Source

emacs / lisp / proced.el

Full commit
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
;;; proced.el --- operate on system processes like dired

;; Copyright (C) 2008-2011 Free Software Foundation, Inc.

;; Author: Roland Winkler <winkler@gnu.org>
;; Keywords: Processes, Unix

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Proced makes an Emacs buffer containing a listing of the current
;; system processes.  You can use the normal Emacs commands to move around
;; in this buffer, and special Proced commands to operate on the processes
;; listed.  See `proced-mode' for getting started.
;;
;; To do:
;; - interactive temporary customizability of flags in `proced-grammar-alist'
;; - allow "sudo kill PID", "renice PID"
;;
;; Thoughts and Ideas
;; - Currently, `process-attributes' returns the list of
;;   command-line arguments of a process as one concatenated string.
;;   This format is compatible with `shell-command'.  Also, under
;;   MS-Windows, the command-line arguments are actually stored as a
;;   single string, so that it is impossible to reverse-engineer it back
;;   into separate arguments.  Alternatively, `process-attributes'
;;   could (try to) return a list of strings that correspond to individual
;;   command-line arguments.  Then one could feed such a list of
;;   command-line arguments into `call-process' or `start-process'.
;;   Are there real-world applications when such a feature would be useful?
;;   What about something like `proced-restart-pid'?

;;; Code:

(require 'time-date)                 ; for `with-decoded-time-value'

(defgroup proced nil
  "Proced mode."
  :group 'processes
  :group 'unix
  :prefix "proced-")

(defcustom proced-signal-function 'signal-process
  "Name of signal function.
It can be an elisp function (usually `signal-process') or a string specifying
the external command (usually \"kill\")."
  :group 'proced
  :type '(choice (function :tag "function")
                 (string :tag "command")))

(defcustom proced-signal-list
  '( ;; signals supported on all POSIX compliant systems
    ("HUP" . "   (1.  Hangup)")
    ("INT" . "   (2.  Terminal interrupt)")
    ("QUIT" . "  (3.  Terminal quit)")
    ("ABRT" . "  (6.  Process abort)")
    ("KILL" . "  (9.  Kill - cannot be caught or ignored)")
    ("ALRM" . "  (14. Alarm Clock)")
    ("TERM" . "  (15. Termination)")
    ;; POSIX 1003.1-2001
    ;; Which systems do not support these signals so that we can
    ;; exclude them from `proced-signal-list'?
    ("CONT" . "  (Continue executing)")
    ("STOP" . "  (Stop executing / pause - cannot be caught or ignored)")
    ("TSTP" . "  (Terminal stop / pause)"))
  "List of signals, used for minibuffer completion."
  :group 'proced
  :type '(repeat (cons (string :tag "signal name")
                       (string :tag "description"))))

;; For which attributes can we use a fixed width of the output field?
;; A fixed width speeds up formatting, yet it can make
;; `proced-grammar-alist' system-dependent.
;; (If proced runs like top(1) we want it to be fast.)
;;
;; If it is impossible / unlikely that an attribute has the same value
;; for two processes, then sorting can be based on one ordinary (fast)
;; predicate like `<'.  Otherwise, a list of proced predicates can be used
;; to refine the sort.
;;
;; It would be neat if one could temporarily override the following
;; predefined rules.
(defcustom proced-grammar-alist
  '( ;; attributes defined in `process-attributes'
    (euid    "EUID"    "%d" right proced-< nil (euid pid) (nil t nil))
    (user    "User"    nil left proced-string-lessp nil (user pid) (nil t nil))
    (egid    "EGID"    "%d" right proced-< nil (egid euid pid) (nil t nil))
    (group   "Group"   nil left proced-string-lessp nil (group user pid) (nil t nil))
    (comm    "Command" nil left proced-string-lessp nil (comm pid) (nil t nil))
    (state   "Stat"    nil left proced-string-lessp nil (state pid) (nil t nil))
    (ppid    "PPID"    "%d" right proced-< nil (ppid pid)
             ((lambda (ppid) (proced-filter-parents proced-process-alist ppid))
              "refine to process parents"))
    (pgrp    "PGrp"    "%d" right proced-< nil (pgrp euid pid) (nil t nil))
    (sess    "Sess"    "%d" right proced-< nil (sess pid) (nil t nil))
    (ttname  "TTY"     proced-format-ttname left proced-string-lessp nil (ttname pid) (nil t nil))
    (tpgid   "TPGID"   "%d" right proced-< nil (tpgid pid) (nil t nil))
    (minflt  "MinFlt"  "%d" right proced-< nil (minflt pid) (nil t t))
    (majflt  "MajFlt"  "%d" right proced-< nil (majflt pid) (nil t t))
    (cminflt "CMinFlt" "%d" right proced-< nil (cminflt pid) (nil t t))
    (cmajflt "CMajFlt" "%d" right proced-< nil (cmajflt pid) (nil t t))
    (utime   "UTime"   proced-format-time right proced-time-lessp t (utime pid) (nil t t))
    (stime   "STime"   proced-format-time right proced-time-lessp t (stime pid) (nil t t))
    (time    "Time"   proced-format-time right proced-time-lessp t (time pid) (nil t t))
    (cutime  "CUTime"  proced-format-time right proced-time-lessp t (cutime pid) (nil t t))
    (cstime  "CSTime"  proced-format-time right proced-time-lessp t (cstime pid) (nil t t))
    (ctime   "CTime"  proced-format-time right proced-time-lessp t (ctime pid) (nil t t))
    (pri     "Pr"      "%d" right proced-< t (pri pid) (nil t t))
    (nice    "Ni"      "%3d" 3 proced-< t (nice pid) (t t nil))
    (thcount "THCount" "%d" right proced-< t (thcount pid) (nil t t))
    (start   "Start"   proced-format-start 6 proced-time-lessp nil (start pid) (t t nil))
    (vsize   "VSize"   "%d" right proced-< t (vsize pid) (nil t t))
    (rss     "RSS"     "%d" right proced-< t (rss pid) (nil t t))
    (etime   "ETime"   proced-format-time right proced-time-lessp t (etime pid) (nil t t))
    (pcpu    "%CPU"    "%.1f" right proced-< t (pcpu pid) (nil t t))
    (pmem    "%Mem"    "%.1f" right proced-< t (pmem pid) (nil t t))
    (args    "Args"    proced-format-args left proced-string-lessp nil (args pid) (nil t nil))
    ;;
    ;; attributes defined by proced (see `proced-process-attributes')
    (pid     "PID"     "%d" right proced-< nil (pid)
             ((lambda (ppid) (proced-filter-children proced-process-alist ppid))
              "refine to process children"))
    ;; process tree
    (tree    "Tree"   proced-format-tree left nil nil nil nil))
  "Alist of rules for handling Proced attributes.

Each element has the form

  (KEY NAME FORMAT JUSTIFY PREDICATE REVERSE SORT-SCHEME REFINER).

Symbol KEY is the car of a process attribute.

String NAME appears in the header line.

FORMAT specifies the format for displaying the attribute values.  It can
be a string passed to `format'.  It can be a function called with one
argument, the value of the attribute.  The value nil means take as is.

If JUSTIFY is an integer, its modulus gives the width of the attribute
values formatted with FORMAT.  If JUSTIFY is positive, NAME appears
right-justified, otherwise it appears left-justified.  If JUSTIFY is 'left
or 'right, the field width is calculated from all field values in the listing.
If JUSTIFY is 'left, the field values are formatted left-justified and
right-justified otherwise.

PREDICATE is the predicate for sorting and filtering the process listing
based on attribute KEY.  PREDICATE takes two arguments P1 and P2,
the corresponding attribute values of two processes.  PREDICATE should
return 'equal if P1 has same rank like P2.  Any other non-nil value says
that P1 is \"less than\" P2, or nil if not.
If PREDICATE is nil the attribute cannot be sorted.

PREDICATE defines an ascending sort order.  REVERSE is non-nil if the sort
order is descending.

SORT-SCHEME is a list (KEY1 KEY2 ...) defining a hierarchy of rules
for sorting the process listing.  KEY1, KEY2, ... are KEYs appearing as cars
of `proced-grammar-alist'.  First the PREDICATE of KEY1 is evaluated.
If it yields non-equal, it defines the sort order for the corresponding
processes.  If it evaluates to 'equal the PREDICATE of KEY2 is evaluated, etc.

REFINER can be a list of flags (LESS-B EQUAL-B LARGER-B) used by the command
`proced-refine' (see there) to refine the listing based on attribute KEY.
This command compares the value of attribute KEY of every process with
the value of attribute KEY of the process at the position of point
using PREDICATE.
If PREDICATE yields non-nil, the process is accepted if LESS-B is non-nil.
If PREDICATE yields 'equal, the process is accepted if EQUAL-B is non-nil.
If PREDICATE yields nil, the process is accepted if LARGER-B is non-nil.

REFINER can also be a list (FUNCTION HELP-ECHO).
FUNCTION is called with one argument, the PID of the process at the position
of point.  The function must return a list of PIDs that is used for the refined
listing.  HELP-ECHO is a string that is shown when mouse is over this field.

If REFINER is nil no refinement is done."
  :group 'proced
  :type '(repeat (list :tag "Attribute"
                       (symbol :tag "Key")
                       (string :tag "Header")
                       (choice :tag "Format"
                               (const :tag "None" nil)
                               (string :tag "Format String")
                               (function :tag "Formatting Function"))
                       (choice :tag "Justification"
                               (const :tag "left" left)
                               (const :tag "right" right)
                               (integer :tag "width"))
                       (choice :tag "Predicate"
                               (const :tag "None" nil)
                               (function :tag "Function"))
                       (boolean :tag "Descending Sort Order")
                       (repeat :tag "Sort Scheme" (symbol :tag "Key"))
                       (choice :tag "Refiner"
                               (const :tag "None" nil)
                               (list (function :tag "Refinement Function")
                                     (string :tag "Help echo"))
                               (list :tag "Refine Flags"
                                     (boolean :tag "Less")
                                     (boolean :tag "Equal")
                                     (boolean :tag "Larger"))))))

(defcustom proced-custom-attributes nil
  "List of functions defining custom attributes.
This variable extends the functionality of `proced-process-attributes'.
Each function is called with one argument, the list of attributes
of a system process.  It returns a cons cell of the form (KEY . VALUE)
like `process-attributes'.  This cons cell is appended to the list
returned by `proced-process-attributes'.
If the function returns nil, the value is ignored."
  :group 'proced
  :type '(repeat (function :tag "Attribute")))

;; Formatting and sorting rules are defined "per attribute".  If formatting
;; and / or sorting should use more than one attribute, it appears more
;; transparent to define a new derived attribute, so that formatting and
;; sorting can use them consistently.  (Are there exceptions to this rule?
;; Would it be advantageous to have yet more general methods available?)
;; Sorting can also be based on attributes that are invisible in the listing.

(defcustom proced-format-alist
  '((short user pid tree pcpu pmem start time (args comm))
    (medium user pid tree pcpu pmem vsize rss ttname state start time (args comm))
    (long user euid group pid tree pri nice pcpu pmem vsize rss ttname state
          start time (args comm))
    (verbose user euid group egid pid ppid tree pgrp sess pri nice pcpu pmem
             state thcount vsize rss ttname tpgid minflt majflt cminflt cmajflt
             start time utime stime ctime cutime cstime etime (args comm)))
  "Alist of formats of listing.
The car of each element is a symbol, the name of the format.
The cdr is a list of attribute keys appearing in `proced-grammar-alist'.
An element of this list may also be a list of attribute keys that specifies
alternatives.  If the first attribute is absent for a process, use the second
one, etc."
  :group 'proced
  :type '(alist :key-type (symbol :tag "Format Name")
                :value-type (repeat :tag "Keys"
                                    (choice (symbol :tag "")
                                            (repeat :tag "Alternative Keys"
                                                    (symbol :tag ""))))))

(defcustom proced-format 'short
  "Current format of Proced listing.
It can be the car of an element of `proced-format-alist'.
It can also be a list of keys appearing in `proced-grammar-alist'."
  :group 'proced
  :type '(choice (symbol :tag "Format Name")
                 (repeat :tag "Keys" (symbol :tag ""))))
(make-variable-buffer-local 'proced-format)

;; FIXME: is there a better name for filter `user' that does not coincide
;; with an attribute key?
(defcustom proced-filter-alist
  `((user (user . ,(concat "\\`" (regexp-quote (user-real-login-name)) "\\'")))
    (user-running (user . ,(concat "\\`" (regexp-quote (user-real-login-name)) "\\'"))
                  (state . "\\`[Rr]\\'"))
    (all)
    (all-running (state . "\\`[Rr]\\'"))
    (emacs (fun-all . (lambda (list)
                        (proced-filter-children list ,(emacs-pid))))))
  "Alist of process filters.
The car of each element is a symbol, the name of the filter.
The cdr is a list of elementary filters that are applied to every process.
A process is displayed if it passes all elementary filters of a selected
filter.

An elementary filter can be one of the following:
\(KEY . REGEXP)   If value of attribute KEY matches REGEXP,
                 accept this process.
\(KEY . FUN)      Apply function FUN to attribute KEY.  Accept this process,
                 if FUN returns non-nil.
\(function . FUN) For each process, apply function FUN to list of attributes
                 of each.  Accept the process if FUN returns non-nil.
\(fun-all . FUN)  Apply function FUN to entire process list.
                 FUN must return the filtered list."
  :group 'proced
  :type '(repeat (cons :tag "Filter"
                       (symbol :tag "Filter Name")
                       (repeat :tag "Filters"
                               (choice (cons :tag "Key . Regexp" (symbol :tag "Key") regexp)
                                       (cons :tag "Key . Function" (symbol :tag "Key") function)
                                       (cons :tag "Function" (const :tag "Key: function" function) function)
                                       (cons :tag "Fun-all" (const :tag "Key: fun-all" fun-all) function))))))

(defcustom proced-filter 'user
  "Current filter of proced listing.
It can be the car of an element of `proced-filter-alist'.
It can also be a list of elementary filters as in the cdrs of the elements
of `proced-filter-alist'."
  :group 'proced
  :type '(choice (symbol :tag "Filter Name")
                 (repeat :tag "Filters"
                         (choice (cons :tag "Key . Regexp" (symbol :tag "Key") regexp)
                                 (cons :tag "Key . Function" (symbol :tag "Key") function)
                                 (cons :tag "Function" (const :tag "Key: function" function) function)
                                 (cons :tag "Fun-all" (const :tag "Key: fun-all" fun-all) function)))))
(make-variable-buffer-local 'proced-filter)

(defcustom proced-sort 'pcpu
  "Current sort scheme for proced listing.
It must be the KEY of an element of `proced-grammar-alist'.
It can also be a list of KEYs as in the SORT-SCHEMEs of the elements
of `proced-grammar-alist'."
  :group 'proced
  :type '(choice (symbol :tag "Sort Scheme")
                 (repeat :tag "Key List" (symbol :tag "Key"))))
(make-variable-buffer-local 'proced-sort)

(defcustom proced-descend t
  "Non-nil if proced listing is sorted in descending order."
  :group 'proced
  :type '(boolean :tag "Descending Sort Order"))
(make-variable-buffer-local 'proced-descend)

(defcustom proced-goal-attribute 'args
  "If non-nil, key of the attribute that defines the `goal-column'."
  :group 'proced
  :type '(choice (const :tag "none" nil)
                 (symbol :tag "key")))

(defcustom proced-auto-update-interval 5
  "Time interval in seconds for auto updating Proced buffers."
  :group 'proced
  :type 'integer)

(defcustom proced-auto-update-flag nil
  "Non-nil for auto update of a Proced buffer.
Can be changed interactively via `proced-toggle-auto-update'."
  :group 'proced
  :type 'boolean)
(make-variable-buffer-local 'proced-auto-update-flag)

(defcustom proced-tree-flag nil
  "Non-nil for display of Proced buffer as process tree."
  :group 'proced
  :type 'boolean)
(make-variable-buffer-local 'proced-tree-flag)

(defcustom proced-post-display-hook nil
  "Normal hook run after displaying or updating a Proced buffer.
May be used to adapt the window size via `fit-window-to-buffer'."
  :type 'hook
  :options '(fit-window-to-buffer)
  :group 'proced)

(defcustom proced-after-send-signal-hook nil
  "Normal hook run after sending a signal to processes by `proced-send-signal'.
May be used to revert the process listing."
  :type 'hook
  :options '(proced-revert)
  :group 'proced)

;; Internal variables

(defvar proced-available (not (null (list-system-processes)))
  "Non-nil means Proced is known to work on this system.")

(defvar proced-process-alist nil
  "Alist of processes displayed by Proced.
The car of each element is the PID, and the cdr is a list of
cons pairs, see `proced-process-attributes'.")
(make-variable-buffer-local 'proced-process-alist)

(defvar proced-sort-internal nil
  "Sort scheme for listing (internal format).
It is a list of lists (KEY PREDICATE REVERSE).")

(defvar proced-marker-char ?*		; the answer is 42
  "In Proced, the current mark character.")

;; Faces and font-lock code taken from dired,
;; but face variables are deprecated for new code.
(defgroup proced-faces nil
  "Faces used by Proced."
  :group 'proced
  :group 'faces)

(defface proced-mark
  '((t (:inherit font-lock-constant-face)))
  "Face used for Proced marks."
  :group 'proced-faces)

(defface proced-marked
  '((t (:inherit error)))
  "Face used for marked processes."
  :group 'proced-faces)

(defface proced-sort-header
  '((t (:inherit font-lock-keyword-face)))
  "Face used for header of attribute used for sorting."
  :group 'proced-faces)

(defvar proced-re-mark "^[^ \n]"
  "Regexp matching a marked line.
Important: the match ends just after the marker.")

(defvar proced-header-line nil
  "Headers in Proced buffer as a string.")
(make-variable-buffer-local 'proced-header-line)

(defvar proced-temp-alist nil
  "Temporary alist (internal variable).")

(defvar proced-process-tree nil
  "Proced process tree (internal variable).")

(defvar proced-tree-depth nil
  "Internal variable for depth of Proced process tree.")

(defvar proced-auto-update-timer nil
  "Stores if Proced auto update timer is already installed.")

(defvar proced-log-buffer "*Proced log*"
  "Name of Proced Log buffer.")

(defconst proced-help-string
  "(n)ext, (p)revious, (m)ark, (u)nmark, (k)ill, (q)uit (type ? for more help)"
  "Help string for Proced.")

(defconst proced-header-help-echo
  "mouse-1, mouse-2: sort by attribute %s%s (%s)"
  "Help string shown when mouse is over a sortable header.")

(defconst proced-field-help-echo
  "mouse-2, RET: refine by attribute %s %s"
  "Help string shown when mouse is over a refinable field.")

(defvar proced-font-lock-keywords
  `(;; (Any) proced marks.
    (,proced-re-mark . 'proced-mark)
    ;; Processes marked with `proced-marker-char'
    ;; Should we make sure that only certain attributes are font-locked?
    (,(concat "^[" (char-to-string proced-marker-char) "]")
     ".+" (proced-move-to-goal-column) nil (0 'proced-marked))))

(defvar proced-mode-map
  (let ((km (make-sparse-keymap)))
    ;; moving
    (define-key km " " 'next-line)
    (define-key km "n" 'next-line)
    (define-key km "p" 'previous-line)
    (define-key km "\C-n" 'next-line)
    (define-key km "\C-p" 'previous-line)
    (define-key km "\C-?" 'previous-line)
    (define-key km [down] 'next-line)
    (define-key km [up] 'previous-line)
    ;; marking
    (define-key km "d" 'proced-mark) ; Dired compatibility ("delete")
    (define-key km "m" 'proced-mark)
    (put 'proced-mark :advertised-binding "m")
    (define-key km "u" 'proced-unmark)
    (define-key km "\177" 'proced-unmark-backward)
    (define-key km "M" 'proced-mark-all)
    (define-key km "U" 'proced-unmark-all)
    (define-key km "t" 'proced-toggle-marks)
    (define-key km "C" 'proced-mark-children)
    (define-key km "P" 'proced-mark-parents)
    ;; filtering
    (define-key km "f"  'proced-filter-interactive)
    (define-key km [mouse-2] 'proced-refine)
    (define-key km "\C-m" 'proced-refine)
    ;; sorting
    (define-key km "sc" 'proced-sort-pcpu)
    (define-key km "sm" 'proced-sort-pmem)
    (define-key km "sp" 'proced-sort-pid)
    (define-key km "ss" 'proced-sort-start)
    (define-key km "sS" 'proced-sort-interactive)
    (define-key km "st" 'proced-sort-time)
    (define-key km "su" 'proced-sort-user)
    ;; similar to `Buffer-menu-sort-by-column'
    (define-key km [header-line mouse-1] 'proced-sort-header)
    (define-key km [header-line mouse-2] 'proced-sort-header)
    (define-key km "T" 'proced-toggle-tree)
    ;; formatting
    (define-key km "F"  'proced-format-interactive)
    ;; operate
    (define-key km "o" 'proced-omit-processes)
    (define-key km "x" 'proced-send-signal) ; Dired compatibility
    (define-key km "k" 'proced-send-signal) ; kill processes
    ;; misc
    (define-key km "h" 'describe-mode)
    (define-key km "?" 'proced-help)
    (define-key km [remap undo] 'proced-undo)
    (define-key km [remap advertised-undo] 'proced-undo)
    ;; Additional keybindings are inherited from `special-mode-map'
    km)
  "Keymap for Proced commands.")

(easy-menu-define
  proced-menu proced-mode-map "Proced Menu"
  `("Proced"
    ["Mark" proced-mark
     :help "Mark Current Process"]
    ["Unmark" proced-unmark
     :help "Unmark Current Process"]
    ["Mark All" proced-mark-all
     :help "Mark All Processes"]
    ["Unmark All" proced-unmark-all
     :help "Unmark All Process"]
    ["Toggle Marks" proced-toggle-marks
     :help "Marked Processes Become Unmarked, and Vice Versa"]
    ["Mark Children" proced-mark-children
     :help "Mark Current Process and its Children"]
    ["Mark Parents" proced-mark-parents
     :help "Mark Current Process and its Parents"]
    "--"
    ("Filters"
     :help "Select Filter for Process Listing"
     ,@(mapcar (lambda (el)
                 (let ((filter (car el)))
                   `[,(symbol-name filter)
                     (proced-filter-interactive ',filter)
                     :style radio
                     :selected (eq proced-filter ',filter)]))
               proced-filter-alist))
    ("Sorting"
     :help "Select Sort Scheme"
     ["Sort..." proced-sort-interactive
      :help "Sort Process List"]
     "--"
     ["Sort by %CPU" proced-sort-pcpu]
     ["Sort by %MEM" proced-sort-pmem]
     ["Sort by PID" proced-sort-pid]
     ["Sort by START" proced-sort-start]
     ["Sort by TIME" proced-sort-time]
     ["Sort by USER" proced-sort-user])
    ("Formats"
     :help "Select Format for Process Listing"
     ,@(mapcar (lambda (el)
                 (let ((format (car el)))
                   `[,(symbol-name format)
                     (proced-format-interactive ',format)
                     :style radio
                     :selected (eq proced-format ',format)]))
               proced-format-alist))
    ["Tree Display" proced-toggle-tree
     :style toggle
     :selected (eval proced-tree-flag)
     :help "Display Proced Buffer as Process Tree"]
    "--"
    ["Omit Marked Processes" proced-omit-processes
     :help "Omit Marked Processes in Process Listing."]
    "--"
    ["Revert" revert-buffer
     :help "Revert Process Listing"]
    ["Auto Update" proced-toggle-auto-update
     :style toggle
     :selected (eval proced-auto-update-flag)
     :help "Auto Update of Proced Buffer"]
    ["Send signal" proced-send-signal
     :help "Send Signal to Marked Processes"]))

;; helper functions
(defun proced-marker-regexp ()
  "Return regexp matching `proced-marker-char'."
  ;; `proced-marker-char' must appear in column zero
  (concat "^" (regexp-quote (char-to-string proced-marker-char))))

(defun proced-success-message (action count)
  "Display success message for ACTION performed for COUNT processes."
  (message "%s %s process%s" action count (if (= 1 count) "" "es")))

;; Unlike dired, we do not define our own commands for vertical motion.
;; If `goal-column' is set, `next-line' and `previous-line' are fancy
;; commands to satisfy our modest needs.  If `proced-goal-attribute'
;; and/or `goal-column' are not set, `next-line' and `previous-line'
;; are really what we need to preserve the column of point.
;; We use `proced-move-to-goal-column' for "non-interactive" cases only
;; to get a well-defined position of point.

(defun proced-move-to-goal-column ()
  "Move to `goal-column' if non-nil.  Return position of point."
  (beginning-of-line)
  (unless (eobp)
    (if goal-column
        (forward-char goal-column)
      (forward-char 2)))
  (point))

(defun proced-header-line ()
  "Return header line for Proced buffer."
  (list (propertize " " 'display '(space :align-to 0))
        (if (<= (window-hscroll) (length proced-header-line))
            (replace-regexp-in-string ;; preserve text properties
             "\\(%\\)" "\\1\\1"
             (substring proced-header-line (window-hscroll))))))

(defun proced-pid-at-point ()
  "Return pid of system process at point.
Return nil if point is not on a process line."
  (save-excursion
    (beginning-of-line)
    (if (looking-at "^. .")
        (get-text-property (match-end 0) 'proced-pid))))

;; proced mode

(define-derived-mode proced-mode special-mode "Proced"
  "Mode for displaying system processes and sending signals to them.
Type \\[proced] to start a Proced session.  In a Proced buffer
type \\<proced-mode-map>\\[proced-mark] to mark a process for later commands.
Type \\[proced-send-signal] to send signals to marked processes.

The initial content of a listing is defined by the variable `proced-filter'
and the variable `proced-format'.
The variable `proced-filter' specifies which system processes are displayed.
The variable `proced-format' specifies which attributes are displayed for
each process.  Type \\[proced-filter-interactive] and \\[proced-format-interactive]
to change the values of `proced-filter' and `proced-format'.
The current value of the variable `proced-filter' is indicated in the
mode line.

The sort order of Proced listings is defined by the variable `proced-sort'.
Type \\[proced-sort-interactive] or click on a header in the header line
to change the sort scheme.  The current sort scheme is indicated in the
mode line, using \"+\" or \"-\" for ascending or descending sort order.

Type \\[proced-toggle-tree] to toggle whether the listing is
displayed as process tree.

An existing Proced listing can be refined by typing \\[proced-refine].
Refining an existing listing does not update the variable `proced-filter'.

The attribute-specific rules for formatting, filtering, sorting, and refining
are defined in `proced-grammar-alist'.

After displaying or updating a Proced buffer, Proced runs the normal hook
`proced-post-display-hook'.

\\{proced-mode-map}"
  (abbrev-mode 0)
  (auto-fill-mode 0)
  (setq buffer-read-only t
        truncate-lines t
        header-line-format '(:eval (proced-header-line)))
  (add-hook 'post-command-hook 'force-mode-line-update nil t)
  (set (make-local-variable 'revert-buffer-function) 'proced-revert)
  (set (make-local-variable 'font-lock-defaults)
       '(proced-font-lock-keywords t nil nil beginning-of-line))
  (if (and (not proced-auto-update-timer) proced-auto-update-interval)
      (setq proced-auto-update-timer
            (run-at-time t proced-auto-update-interval
                         'proced-auto-update-timer))))

;;;###autoload
(defun proced (&optional arg)
  "Generate a listing of UNIX system processes.
If invoked with optional ARG the window displaying the process
information will be displayed but not selected.
Runs the normal hook `proced-post-display-hook'.

See `proced-mode' for a description of features available in Proced buffers."
  (interactive "P")
  (unless proced-available
    (error "Proced is not available on this system"))
  (let ((buffer (get-buffer-create "*Proced*")) new)
    (set-buffer buffer)
    (setq new (zerop (buffer-size)))
    (when new
      (proced-mode)
      ;; `proced-update' runs `proced-post-display-hook' only if the
      ;; Proced buffer has been selected.  Yet the following call of
      ;; `proced-update' is for an empty Proced buffer that has not
      ;; yet been selected.  Therefore we need to call
      ;; `proced-post-display-hook' below.
      (proced-update t))
    (if arg
        (progn
          (display-buffer buffer)
          (with-current-buffer buffer
            (proced-update t)))
      (pop-to-buffer buffer)
      (proced-update t)
      (message
       (substitute-command-keys
        "Type \\<proced-mode-map>\\[quit-window] to quit, \\[proced-help] for help")))))

(defun proced-auto-update-timer ()
  "Auto-update Proced buffers using `run-at-time'."
  (dolist (buf (buffer-list))
    (with-current-buffer buf
      (if (and (eq major-mode 'proced-mode)
               proced-auto-update-flag)
          (proced-update t t)))))

(defun proced-toggle-auto-update (arg)
  "Change whether this Proced buffer is updated automatically.
With prefix ARG, update this buffer automatically if ARG is positive,
otherwise do not update.  Sets the variable `proced-auto-update-flag'.
The time interval for updates is specified via `proced-auto-update-interval'."
  (interactive (list (or current-prefix-arg 'toggle)))
  (setq proced-auto-update-flag
        (cond ((eq arg 'toggle) (not proced-auto-update-flag))
              (arg (> (prefix-numeric-value arg) 0))
              (t (not proced-auto-update-flag))))
  (message "Proced auto update %s"
           (if proced-auto-update-flag "enabled" "disabled")))

;;; Mark

(defun proced-mark (&optional count)
  "Mark the current (or next COUNT) processes."
  (interactive "p")
  (proced-do-mark t count))

(defun proced-unmark (&optional count)
  "Unmark the current (or next COUNT) processes."
  (interactive "p")
  (proced-do-mark nil count))

(defun proced-unmark-backward (&optional count)
  "Unmark the previous (or COUNT previous) processes."
  ;; Analogous to `dired-unmark-backward',
  ;; but `ibuffer-unmark-backward' behaves different.
  (interactive "p")
  (proced-do-mark nil (- (or count 1))))

(defun proced-do-mark (mark &optional count)
  "Mark the current (or next COUNT) processes using MARK."
  (or count (setq count 1))
  (let ((backward (< count 0))
	buffer-read-only)
    (setq count (1+ (if (<= 0 count) count
                      (min (1- (line-number-at-pos)) (abs count)))))
    (beginning-of-line)
    (while (not (or (zerop (setq count (1- count))) (eobp)))
      (proced-insert-mark mark backward))
    (proced-move-to-goal-column)))

(defun proced-toggle-marks ()
  "Toggle marks: marked processes become unmarked, and vice versa."
  (interactive)
  (let ((mark-re (proced-marker-regexp))
        buffer-read-only)
    (save-excursion
      (goto-char (point-min))
      (while (not (eobp))
        (cond ((looking-at mark-re)
               (proced-insert-mark nil))
              ((looking-at " ")
               (proced-insert-mark t))
              (t
               (forward-line 1)))))))

(defun proced-insert-mark (mark &optional backward)
  "If MARK is non-nil, insert `proced-marker-char'.
If BACKWARD is non-nil, move one line backwards before inserting the mark.
Otherwise move one line forward after inserting the mark."
  (if backward (forward-line -1))
  (insert (if mark proced-marker-char ?\s))
  (delete-char 1)
  (unless backward (forward-line)))

(defun proced-mark-all ()
  "Mark all processes.
If `transient-mark-mode' is turned on and the region is active,
mark the region."
  (interactive)
  (proced-do-mark-all t))

(defun proced-unmark-all ()
  "Unmark all processes.
If `transient-mark-mode' is turned on and the region is active,
unmark the region."
  (interactive)
  (proced-do-mark-all nil))

(defun proced-do-mark-all (mark)
  "Mark all processes using MARK.
If `transient-mark-mode' is turned on and the region is active,
mark the region."
  (let* ((count 0)
         (proced-marker-char (if mark proced-marker-char ?\s))
         (marker-re (proced-marker-regexp))
         end buffer-read-only)
    (save-excursion
      (if (use-region-p)
          ;; Operate even on those lines that are only partially a part
          ;; of region.  This appears most consistent with
          ;; `proced-move-to-goal-column'.
          (progn (setq end (save-excursion
                             (goto-char (region-end))
                             (unless (looking-at "^") (forward-line))
                             (point)))
                 (goto-char (region-beginning))
                 (unless (looking-at "^") (beginning-of-line)))
        (goto-char (point-min))
        (setq end (point-max)))
      (while (< (point) end)
        (unless (looking-at marker-re)
          (setq count (1+ count))
          (insert proced-marker-char)
          (delete-char 1))
        (forward-line))
      (proced-success-message (if mark "Marked" "Unmarked") count))))

(defun proced-mark-children (ppid &optional omit-ppid)
  "Mark child processes of process PPID.
Also mark process PPID unless prefix OMIT-PPID is non-nil."
  (interactive (list (proced-pid-at-point) current-prefix-arg))
  (proced-mark-process-alist
   (proced-filter-children proced-process-alist ppid omit-ppid)))

(defun proced-mark-parents (cpid &optional omit-cpid)
  "Mark parent processes of process CPID.
Also mark CPID unless prefix OMIT-CPID is non-nil."
  (interactive (list (proced-pid-at-point) current-prefix-arg))
  (proced-mark-process-alist
   (proced-filter-parents proced-process-alist cpid omit-cpid)))

(defun proced-mark-process-alist (process-alist &optional quiet)
  "Mark processes in PROCESS-ALIST.
If QUIET is non-nil suppress status message."
  (let ((count 0))
    (if process-alist
        (let (buffer-read-only)
          (save-excursion
            (goto-char (point-min))
            (while (not (eobp))
              (when (assq (proced-pid-at-point) process-alist)
                (insert proced-marker-char)
                (delete-char 1)
                (setq count (1+ count)))
              (forward-line)))))
    (unless quiet
      (proced-success-message "Marked" count))))

;; Mostly analog of `dired-do-kill-lines'.
;; However, for negative args the target lines of `dired-do-kill-lines'
;; include the current line, whereas `dired-mark' for negative args operates
;; on the preceding lines.  Here we are consistent with `dired-mark'.
(defun proced-omit-processes (&optional arg quiet)
  "Omit marked processes.
With prefix ARG, omit that many lines starting with the current line.
\(A negative argument omits backward.)
If `transient-mark-mode' is turned on and the region is active,
omit the processes in region.
If QUIET is non-nil suppress status message.
Returns count of omitted lines."
  (interactive "P")
  (let ((mark-re (proced-marker-regexp))
        (count 0)
        buffer-read-only)
    (cond ((use-region-p) ;; Omit active region
           (let ((lines (count-lines (region-beginning) (region-end))))
             (save-excursion
               (goto-char (region-beginning))
               (while (< count lines)
                 (proced-omit-process)
                 (setq count (1+ count))))))
          ((not arg) ;; Omit marked lines
           (save-excursion
             (goto-char (point-min))
             (while (and (not (eobp))
                         (re-search-forward mark-re nil t))
               (proced-omit-process)
               (setq count (1+ count)))))
          ((< 0 arg) ;; Omit forward
           (while (and (not (eobp)) (< count arg))
             (proced-omit-process)
             (setq count (1+ count))))
          ((< arg 0) ;; Omit backward
           (while (and (not (bobp)) (< count (- arg)))
             (forward-line -1)
             (proced-omit-process)
             (setq count (1+ count)))))
    (unless (zerop count) (proced-move-to-goal-column))
    (unless quiet (proced-success-message "Omitted" count))
    count))

(defun proced-omit-process ()
  "Omit process from listing point is on.
Update `proced-process-alist' accordingly."
  (setq proced-process-alist
        (assq-delete-all (proced-pid-at-point) proced-process-alist))
  (delete-region (line-beginning-position)
                 (save-excursion (forward-line) (point))))

;;; Filtering

(defun proced-filter (process-alist filter-list)
  "Apply FILTER-LIST to PROCESS-ALIST.
Return the filtered process list."
  (if (symbolp filter-list)
      (setq filter-list (cdr (assq filter-list proced-filter-alist))))
  (dolist (filter filter-list)
    (let (new-alist)
      (cond ( ;; apply function to entire process list
             (eq (car filter) 'fun-all)
             (setq new-alist (funcall (cdr filter) process-alist)))
            ( ;; apply predicate to each list of attributes
             (eq (car filter) 'function)
             (dolist (process process-alist)
               (if (funcall (car filter) (cdr process))
                   (push process new-alist))))
            (t ;; apply predicate to specified attribute
             (let ((fun (if (stringp (cdr filter))
                            `(lambda (val)
                               (string-match ,(cdr filter) val))
                          (cdr filter)))
                   value)
               (dolist (process process-alist)
                 (setq value (cdr (assq (car filter) (cdr process))))
                 (if (and value (funcall fun value))
                     (push process new-alist))))))
      (setq process-alist new-alist)))
  process-alist)

(defun proced-filter-interactive (scheme)
  "Filter Proced buffer using SCHEME.
When called interactively, an empty string means nil, i.e., no filtering.
Set variable `proced-filter' to SCHEME.  Revert listing."
  (interactive
   (let ((scheme (completing-read "Filter: "
                                  proced-filter-alist nil t)))
     (list (if (string= "" scheme) nil (intern scheme)))))
  ;; only update if necessary
  (unless (eq proced-filter scheme)
    (setq proced-filter scheme)
    (proced-update t)))

(defun proced-filter-parents (process-alist pid &optional omit-pid)
  "For PROCESS-ALIST return list of parent processes of PID.
This list includes PID unless OMIT-PID is non-nil."
  (let ((parent-list (unless omit-pid (list (assq pid process-alist))))
        (process (assq pid process-alist))
        ppid)
    (while (and (setq ppid (cdr (assq 'ppid (cdr process))))
                ;; Ignore a PPID that equals PID.
                (/= ppid pid)
                ;; Accept only PPIDs that correspond to members in PROCESS-ALIST.
                (setq process (assq ppid process-alist)))
      (setq pid ppid)
      (push process parent-list))
    parent-list))

(defun proced-filter-children (process-alist ppid &optional omit-ppid)
  "For PROCESS-ALIST return list of child processes of PPID.
This list includes PPID unless OMIT-PPID is non-nil."
  (let ((proced-temp-alist (proced-children-alist process-alist))
        new-alist)
    (dolist (pid (proced-children-pids ppid))
      (push (assq pid process-alist) new-alist))
    (if omit-ppid
        (assq-delete-all ppid new-alist)
      new-alist)))

;;; Process tree

(defun proced-children-alist (process-alist)
  "Return children alist for PROCESS-ALIST.
The children alist has elements (PPID PID1 PID2 ...).
PPID is a parent PID.  PID1, PID2, ... are the child processes of PPID.
The children alist inherits the sorting order of PROCESS-ALIST.
The list of children does not include grandchildren."
  ;; The PPIDs inherit the sorting order of PROCESS-ALIST.
  (let ((process-tree (mapcar (lambda (a) (list (car a))) process-alist))
        ppid)
    (dolist (process process-alist)
      (setq ppid (cdr (assq 'ppid (cdr process))))
      (if (and ppid
               ;; Ignore a PPID that equals PID.
               (/= ppid (car process))
               ;; Accept only PPIDs that correspond to members in PROCESS-ALIST.
               (assq ppid process-alist))
          (let ((temp-alist process-tree) elt)
            (while (setq elt (pop temp-alist))
              (when (eq ppid (car elt))
                (setq temp-alist nil)
                (setcdr elt (cons (car process) (cdr elt))))))))
    ;; The child processes inherit the sorting order of PROCESS-ALIST.
    (setq process-tree
          (mapcar (lambda (a) (cons (car a) (nreverse (cdr a))))
                  process-tree))))

(defun proced-children-pids (ppid)
  "Return list of children PIDs of PPID (including PPID)."
  (let ((cpids (cdr (assq ppid proced-temp-alist))))
    (if cpids
        (cons ppid (apply 'append (mapcar 'proced-children-pids cpids)))
      (list ppid))))

(defun proced-process-tree (process-alist)
  "Return process tree for PROCESS-ALIST.
It is an alist of alists where the car of each alist is a parent process
and the cdr is a list of child processes according to the ppid attribute
of these processes.
The process tree inherits the sorting order of PROCESS-ALIST."
  (let ((proced-temp-alist (proced-children-alist process-alist))
        pid-alist proced-process-tree)
    (while (setq pid-alist (pop proced-temp-alist))
      (push (proced-process-tree-internal pid-alist) proced-process-tree))
    (nreverse proced-process-tree)))

(defun proced-process-tree-internal (pid-alist)
  "Helper function for `proced-process-tree'."
  (let ((cpid-list (cdr pid-alist)) cpid-alist cpid)
    (while (setq cpid (car cpid-list))
      (if (setq cpid-alist (assq cpid proced-temp-alist))
          ;; Unprocessed part of process tree that needs to be
          ;; analyzed recursively.
          (progn
            (setq proced-temp-alist
                  (assq-delete-all cpid proced-temp-alist))
            (setcar cpid-list (proced-process-tree-internal cpid-alist)))
        ;; We already processed this subtree and take it "as is".
        (setcar cpid-list (assq cpid proced-process-tree))
        (setq proced-process-tree
              (assq-delete-all cpid proced-process-tree)))
      (pop cpid-list)))
  pid-alist)

(defun proced-toggle-tree (arg)
  "Toggle the display of the process listing as process tree.
With prefix ARG, display as process tree if ARG is positive, otherwise
do not display as process tree.  Sets the variable `proced-tree-flag'.

The process tree is generated from the selected processes in the
Proced buffer (that is, the processes in `proced-process-alist').
All processes that do not have a parent process in this list
according to their ppid attribute become the root of a process tree.
Each parent process is followed by its child processes.
The process tree inherits the chosen sorting order of the process listing,
that is, child processes of the same parent process are sorted using
the selected sorting order."
  (interactive (list (or current-prefix-arg 'toggle)))
  (setq proced-tree-flag
        (cond ((eq arg 'toggle) (not proced-tree-flag))
              (arg (> (prefix-numeric-value arg) 0))
              (t (not proced-tree-flag))))
  (proced-update)
  (message "Proced process tree display %s"
           (if proced-tree-flag "enabled" "disabled")))

(defun proced-tree (process-alist)
  "Rearrange PROCESS-ALIST as process tree.
If `proced-tree-flag' is non-nil, rearrange PROCESS-ALIST such that
every processes is followed by its child processes.  Each process
gets a tree attribute that specifies the depth of the process in the tree.
A root process is a process with no parent within PROCESS-ALIST according
to its value of the ppid attribute.  It has depth 0.

If `proced-tree-flag' is nil, remove the tree attribute.
Return the rearranged process list."
  (if proced-tree-flag
      ;; add tree attribute
      (let ((process-tree (proced-process-tree process-alist))
            (proced-tree-depth 0)
            (proced-temp-alist process-alist)
            proced-process-tree pt)
        (while (setq pt (pop process-tree))
          (proced-tree-insert pt))
        (nreverse proced-process-tree))
    ;; remove tree attribute
    (let ((process-alist process-alist))
      (while process-alist
        (setcar process-alist
                (assq-delete-all 'tree (car process-alist)))
        (pop process-alist)))
    process-alist))

(defun proced-tree-insert (process-tree)
  "Helper function for `proced-tree'."
  (let ((pprocess (assq (car process-tree) proced-temp-alist)))
    (push (append (list (car pprocess))
                  (list (cons 'tree proced-tree-depth))
                  (cdr pprocess))
          proced-process-tree)
    (if (cdr process-tree)
        (let ((proced-tree-depth (1+ proced-tree-depth)))
          (mapc 'proced-tree-insert (cdr process-tree))))))

;; Refining

;; Filters are used to select the processes in a new listing.
;; Refiners are used to narrow down further (interactively) the processes
;; in an existing listing.

(defun proced-refine (&optional event)
  "Refine Proced listing by comparing with the attribute value at point.
Optional EVENT is the location of the Proced field.

Refinement is controlled by the REFINER defined for each attribute ATTR
in `proced-grammar-alist'.

If REFINER is a list of flags and point is on a process's value of ATTR,
this command compares the value of ATTR of every process with the value
of ATTR of the process at the position of point.

The predicate for the comparison of two ATTR values is defined
in `proced-grammar-alist'.  For each return value of the predicate
a refine flag is defined in `proced-grammar-alist'.  One can select
processes for which the value of ATTR is \"less than\", \"equal\",
and / or \"larger\" than ATTR of the process point is on.  A process
is included in the new listing if the refine flag for the corresponding
return value of the predicate is non-nil.
The help-echo string for `proced-refine' uses \"+\" or \"-\" to indicate
the current values of these refine flags.

If REFINER is a cons pair (FUNCTION . HELP-ECHO), FUNCTION is called
with one argument, the PID of the process at the position of point.
The function must return a list of PIDs that is used for the refined
listing.  HELP-ECHO is a string that is shown when mouse is over this field.

This command refines an already existing process listing generated initially
based on the value of the variable `proced-filter'.  It does not change
this variable.  It does not revert the listing.  If you frequently need
a certain refinement, consider defining a new filter in `proced-filter-alist'."
  (interactive (list last-input-event))
  (if event (posn-set-point (event-end event)))
  (let ((key (get-text-property (point) 'proced-key))
        (pid (get-text-property (point) 'proced-pid)))
    (if (and key pid)
        (let* ((grammar (assq key proced-grammar-alist))
               (refiner (nth 7 grammar)))
          (when refiner
            (cond ((functionp (car refiner))
                   (setq proced-process-alist (funcall (car refiner) pid)))
                  ((consp refiner)
                   (let ((predicate (nth 4 grammar))
                         (ref (cdr (assq key (cdr (assq pid proced-process-alist)))))
                         val new-alist)
                     (dolist (process proced-process-alist)
                       (setq val (funcall predicate (cdr (assq key (cdr process))) ref))
                       (if (cond ((not val) (nth 2 refiner))
                                 ((eq val 'equal) (nth 1 refiner))
                                 (val (car refiner)))
                           (push process new-alist)))
                     (setq proced-process-alist new-alist))))
            ;; Do not revert listing.
            (proced-update)))
      (message "No refiner defined here."))))

;; Proced predicates for sorting and filtering are based on a three-valued
;; logic:
;; Predicates take two arguments P1 and P2, the corresponding attribute
;; values of two processes.  Predicates should return 'equal if P1 has
;; same rank like P2.  Any other non-nil value says that P1 is "less than" P2,
;; or nil if not.

(defun proced-< (num1 num2)
  "Return t if NUM1 less than NUM2.
Return `equal' if NUM1 equals NUM2.  Return nil if NUM1 greater than NUM2."
  (if (= num1 num2)
      'equal
    (< num1 num2)))

(defun proced-string-lessp (s1 s2)
  "Return t if string S1 is less than S2 in lexicographic order.
Return `equal' if S1 and S2 have identical contents.
Return nil otherwise."
  (if (string= s1 s2)
      'equal
    (string-lessp s1 s2)))

(defun proced-time-lessp (t1 t2)
  "Return t if time value T1 is less than time value T2.
Return `equal' if T1 equals T2.  Return nil otherwise."
  (with-decoded-time-value ((high1 low1 micro1 t1)
			    (high2 low2 micro2 t2))
    (cond ((< high1 high2))
          ((< high2 high1) nil)
          ((< low1 low2))
          ((< low2 low1) nil)
          ((< micro1 micro2))
          ((< micro2 micro1) nil)
          (t 'equal))))

;;; Sorting

(defsubst proced-xor (b1 b2)
  "Return the logical exclusive or of args B1 and B2."
  (and (or b1 b2)
       (not (and b1 b2))))

(defun proced-sort-p (p1 p2)
  "Predicate for sorting processes P1 and P2."
  (if (not (cdr proced-sort-internal))
      ;; only one predicate: fast scheme
      (let* ((sorter (car proced-sort-internal))
             (k1 (cdr (assq (car sorter) (cdr p1))))
             (k2 (cdr (assq (car sorter) (cdr p2)))))
        ;; if the attributes are undefined, we should really abort sorting
        (if (and k1 k2)
            (proced-xor (funcall (nth 1 sorter) k1 k2)
                        (nth 2 sorter))))
    (let ((sort-list proced-sort-internal) sorter predicate k1 k2)
      (catch 'done
        (while (setq sorter (pop sort-list))
          (setq k1 (cdr (assq (car sorter) (cdr p1)))
                k2 (cdr (assq (car sorter) (cdr p2)))
                predicate
                (if (and k1 k2)
                    (funcall (nth 1 sorter) k1 k2)))
          (if (not (eq predicate 'equal))
              (throw 'done (proced-xor predicate (nth 2 sorter)))))
        (eq t predicate)))))

(defun proced-sort (process-alist sorter descend)
  "Sort PROCESS-ALIST using scheme SORTER.
SORTER is a scheme like `proced-sort'.
DESCEND is non-nil if the first element of SORTER is sorted
in descending order.
Return the sorted process list."
  ;; translate SORTER into a list of lists (KEY PREDICATE REVERSE)
  (setq proced-sort-internal
        (mapcar (lambda (arg)
                  (let ((grammar (assq arg proced-grammar-alist)))
                    (unless (nth 4 grammar)
                      (error "Attribute %s not sortable" (car grammar)))
                    (list arg (nth 4 grammar) (nth 5 grammar))))
                (cond ((listp sorter) sorter)
                      ((and (symbolp sorter)
                            (nth 6 (assq sorter proced-grammar-alist))))
                      ((symbolp sorter) (list sorter))
                      (t (error "Sorter undefined %s" sorter)))))
  (if proced-sort-internal
      (progn
        ;; splice DESCEND into the list
        (setcar proced-sort-internal
                (list (caar proced-sort-internal)
                      (nth 1 (car proced-sort-internal)) descend))
        (sort process-alist 'proced-sort-p))
    process-alist))

(defun proced-sort-interactive (scheme &optional arg)
  "Sort Proced buffer using SCHEME.
When called interactively, an empty string means nil, i.e., no sorting.

Prefix ARG controls sort order:
- If prefix ARG is positive (negative), sort in ascending (descending) order.
- If ARG is nil or 'no-arg and SCHEME is equal to the previous sorting scheme,
  reverse the sorting order.
- If ARG is nil or 'no-arg and SCHEME differs from the previous sorting scheme,
  adopt the sorting order defined for SCHEME in `proced-grammar-alist'.

Set variable `proced-sort' to SCHEME.  The current sort scheme is displayed
in the mode line, using \"+\" or \"-\" for ascending or descending order."
  (interactive
   (let* (choices
          (scheme (completing-read "Sort attribute: "
                                   (dolist (grammar proced-grammar-alist choices)
                                     (if (nth 4 grammar)
                                         (push (list (car grammar)) choices)))
                                   nil t)))
     (list (if (string= "" scheme) nil (intern scheme))
           ;; like 'toggle in `define-derived-mode'
           (or current-prefix-arg 'no-arg))))

  (setq proced-descend
        ;; If `proced-sort-interactive' is called repeatedly for the same
        ;; sort key, the sort order is reversed.
        (cond ((and (eq arg 'no-arg) (equal proced-sort scheme))
               (not proced-descend))
              ((eq arg 'no-arg)
               (nth 5 (assq (if (consp scheme) (car scheme) scheme)
                            proced-grammar-alist)))
              (arg (< (prefix-numeric-value arg) 0))
              ((equal proced-sort scheme)
               (not proced-descend))
              (t (nth 5 (assq (if (consp scheme) (car scheme) scheme)
                                   proced-grammar-alist))))
        proced-sort scheme)
  (proced-update))

(defun proced-sort-pcpu (&optional arg)
  "Sort Proced buffer by percentage CPU time (%CPU).
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'pcpu arg))

(defun proced-sort-pmem (&optional arg)
  "Sort Proced buffer by percentage memory usage (%MEM).
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'pmem arg))

(defun proced-sort-pid (&optional arg)
  "Sort Proced buffer by PID.
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'pid arg))

(defun proced-sort-start (&optional arg)
  "Sort Proced buffer by time the command started (START).
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'start arg))

(defun proced-sort-time (&optional arg)
  "Sort Proced buffer by CPU time (TIME).
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'time arg))

(defun proced-sort-user (&optional arg)
  "Sort Proced buffer by USER.
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list (or current-prefix-arg 'no-arg)))
  (proced-sort-interactive 'user arg))

(defun proced-sort-header (event &optional arg)
  "Sort Proced listing based on an attribute.
EVENT is a mouse event with starting position in the header line.
It is converted to the corresponding attribute key.
This command updates the variable `proced-sort'.
Prefix ARG controls sort order, see `proced-sort-interactive'."
  (interactive (list last-input-event (or last-prefix-arg 'no-arg)))
  (let ((start (event-start event))
        col key)
    (save-selected-window
      (select-window (posn-window start))
      (setq col (+ (1- (car (posn-actual-col-row start)))
                   (window-hscroll)))
      (when (and (<= 0 col) (< col (length proced-header-line)))
        (setq key (get-text-property col 'proced-key proced-header-line))
        (if key
            (proced-sort-interactive key arg)
          (message "No sorter defined here."))))))

;;; Formatting

(defun proced-format-time (time)
  "Format time interval TIME."
  (let* ((ftime (float-time time))
         (days (truncate ftime 86400))
         (ftime (mod ftime 86400))
         (hours (truncate ftime 3600))
         (ftime (mod ftime 3600))
         (minutes (truncate ftime 60))
         (seconds (mod ftime 60)))
    (cond ((< 0 days)
           (format "%d-%02d:%02d:%02d" days hours minutes seconds))
          ((< 0 hours)
           (format "%02d:%02d:%02d" hours minutes seconds))
          (t
           (format "%02d:%02d" minutes seconds)))))

(defun proced-format-start (start)
  "Format time START.
The return string is always 6 characters wide."
  (let ((d-start (decode-time start))
        (d-current (decode-time)))
    (cond ( ;; process started in previous years
           (< (nth 5 d-start) (nth 5 d-current))
           (format-time-string "  %Y" start))
          ;; process started today
          ((and (= (nth 3 d-start) (nth 3 d-current))
                (= (nth 4 d-start) (nth 4 d-current)))
           (format-time-string " %H:%M" start))
          (t ;; process started this year
           (format-time-string "%b %e" start)))))

(defun proced-format-ttname (ttname)
  "Format attribute TTNAME, omitting path \"/dev/\"."
  ;; Does this work for all systems?
  (substring ttname (if (string-match "\\`/dev/" ttname)
                        (match-end 0) 0)))

(defun proced-format-tree (tree)
  "Format attribute TREE."
  (concat (make-string tree ?\s) (number-to-string tree)))

;; Proced assumes that every process occupies only one line in the listing.
(defun proced-format-args (args)
  "Format attribute ARGS.
Replace newline characters by \"^J\" (two characters)."
  (replace-regexp-in-string "\n" "^J" args))

(defun proced-format (process-alist format)
  "Display PROCESS-ALIST using FORMAT."
  (if (symbolp format)
      (setq format (cdr (assq format proced-format-alist))))

  ;; Not all systems give us all attributes.  We take `emacs-pid' as a
  ;; representative process PID.  If FORMAT contains a list of alternative
  ;; attributes, we take the first attribute that is non-nil for `emacs-pid'.
  ;; If none of the alternatives is non-nil, the attribute is ignored
  ;; in the listing.
  (let ((standard-attributes
         (car (proced-process-attributes (list (emacs-pid)))))
        new-format fmi)
    (if (and proced-tree-flag
             (assq 'ppid standard-attributes))
        (push (cons 'tree 0) standard-attributes))
    (dolist (fmt format)
      (if (symbolp fmt)
          (if (assq fmt standard-attributes)
              (push fmt new-format))
        (while (setq fmi (pop fmt))
          (when (assq fmi standard-attributes)
            (push fmi new-format)
            (setq fmt nil)))))
    (setq format (nreverse new-format)))

  (insert (make-string (length process-alist) ?\n))
  (let ((whitespace " ") (unknown "?")
        (sort-key (if (consp proced-sort) (car proced-sort) proced-sort))
        header-list grammar)
    ;; Loop over all attributes
    (while (setq grammar (assq (pop format) proced-grammar-alist))
      (let* ((key (car grammar))
             (fun (cond ((stringp (nth 2 grammar))
                         `(lambda (arg) (format ,(nth 2 grammar) arg)))
                        ((not (nth 2 grammar)) 'identity)
                        ( t (nth 2 grammar))))
             (whitespace (if format whitespace ""))
             ;; Text properties:
             ;; We use the text property `proced-key' to store in each
             ;; field the corresponding key.
             ;; Of course, the sort predicate appearing in help-echo
             ;; is only part of the story.  But it gives the main idea.
             (hprops
              (if (nth 4 grammar)
                  (let ((descend (if (eq key sort-key) proced-descend (nth 5 grammar))))
                    `(proced-key ,key mouse-face highlight
                                 help-echo ,(format proced-header-help-echo
                                                    (if descend "-" "+")
                                                    (nth 1 grammar)
                                                    (if descend "descending" "ascending"))))))
             (refiner (nth 7 grammar))
             (fprops
              (cond ((functionp (car refiner))
                     `(proced-key ,key mouse-face highlight
                                  help-echo ,(format "mouse-2, RET: %s"
                                                     (nth 1 refiner))))
                    ((consp refiner)
                     `(proced-key ,key mouse-face highlight
                                  help-echo ,(format "mouse-2, RET: refine by attribute %s %s"
                                                     (nth 1 grammar)
                                                     (mapconcat (lambda (s)
                                                                  (if s "+" "-"))
                                                                refiner ""))))))
             value)

        ;; highlight the header of the sort column
        (if (eq key sort-key)
            (setq hprops (append '(face proced-sort-header) hprops)))
        (goto-char (point-min))
        (cond ( ;; fixed width of output field
               (numberp (nth 3 grammar))
               (dolist (process process-alist)
                 (end-of-line)
                 (setq value (cdr (assq key (cdr process))))
                 (insert (if value
                             (apply 'propertize (funcall fun value) fprops)
                           (format (concat "%" (number-to-string (nth 3 grammar)) "s")
                                   unknown))
                         whitespace)
                 (forward-line))
               (push (format (concat "%" (number-to-string (nth 3 grammar)) "s")
                             (apply 'propertize (nth 1 grammar) hprops))
                     header-list))

              ( ;; last field left-justified
               (and (not format) (eq 'left (nth 3 grammar)))
               (dolist (process process-alist)
                 (end-of-line)
                 (setq value (cdr (assq key (cdr process))))
                 (insert (if value (apply 'propertize (funcall fun value) fprops)
                           unknown))
                 (forward-line))
               (push (apply 'propertize (nth 1 grammar) hprops) header-list))

              (t ;; calculated field width
               (let ((width (length (nth 1 grammar)))
                     field-list value)
                 (dolist (process process-alist)
                   (setq value (cdr (assq key (cdr process))))
                   (if value
                       (setq value (apply 'propertize (funcall fun value) fprops)
                             width (max width (length value))
                             field-list (cons value field-list))
                     (push unknown field-list)
                     (setq width (max width (length unknown)))))
                 (let ((afmt (concat "%" (if (eq 'left (nth 3 grammar)) "-" "")
                                     (number-to-string width) "s")))
                   (push (format afmt (apply 'propertize (nth 1 grammar) hprops))
                         header-list)
                   (dolist (value (nreverse field-list))
                     (end-of-line)
                     (insert (format afmt value) whitespace)
                     (forward-line))))))))

    ;; final cleanup
    (goto-char (point-min))
    (dolist (process process-alist)
      ;; We use the text property `proced-pid' to store in each line
      ;; the corresponding pid
      (put-text-property (point) (line-end-position) 'proced-pid (car process))
      (forward-line))
    ;; Set header line
    (setq proced-header-line
          (mapconcat 'identity (nreverse header-list) whitespace))
    (if (string-match "[ \t]+$" proced-header-line)
        (setq proced-header-line (substring proced-header-line 0
                                            (match-beginning 0))))
    ;; (delete-trailing-whitespace)
    (goto-char (point-min))
    (while (re-search-forward "[ \t\r]+$" nil t)
      (delete-region (match-beginning 0) (match-end 0)))))

(defun proced-format-interactive (scheme &optional revert)
  "Format Proced buffer using SCHEME.
When called interactively, an empty string means nil, i.e., no formatting.
Set variable `proced-format' to SCHEME.
With prefix REVERT non-nil revert listing."
  (interactive
   (let ((scheme (completing-read "Format: "
                                  proced-format-alist nil t)))
     (list (if (string= "" scheme) nil (intern scheme))
           current-prefix-arg)))
  ;; only update if necessary
  (when (or (not (eq proced-format scheme)) revert)
    (setq proced-format scheme)
    (proced-update revert)))

;; generate listing

(defun proced-process-attributes (&optional pid-list)
  "Return alist of attributes for each system process.
This alist can be customized via `proced-custom-attributes'.
Optional arg PID-LIST is a list of PIDs of system process that are analyzed.
If no attributes are known for a process (possibly because it already died)
the process is ignored."
  ;; Should we make it customizable whether processes with empty attribute
  ;; lists are ignored?  When would such processes be of interest?
  (let (process-alist attributes attr)
    (dolist (pid (or pid-list (list-system-processes)) process-alist)
      (when (setq attributes (process-attributes pid))
        (setq attributes (cons (cons 'pid pid) attributes))
        (dolist (fun proced-custom-attributes)
          (if (setq attr (funcall fun attributes))
              (push attr attributes)))
        (push (cons pid attributes) process-alist)))))

(defun proced-update (&optional revert quiet)
  "Update the Proced process information.  Preserves point and marks.
With prefix REVERT non-nil, revert listing.
Suppress status information if QUIET is nil.
After updating a displayed Proced buffer run the normal hook
`proced-post-display-hook'."
  ;; This is the main function that generates and updates the process listing.
  (interactive "P")
  (setq revert (or revert (not proced-process-alist)))
  (or quiet (message (if revert "Updating process information..."
                       "Updating process display...")))
  (if revert ;; evaluate all processes
      (setq proced-process-alist (proced-process-attributes)))
  ;; filtering and sorting
  (setq proced-process-alist
        (proced-sort (proced-filter proced-process-alist proced-filter)
                     proced-sort proced-descend))

  ;; display as process tree?
  (setq proced-process-alist
        (proced-tree proced-process-alist))

  ;; It is useless to keep undo information if we revert, filter, or
  ;; refine the listing so that `proced-process-alist' has changed.
  ;; We could keep the undo information if we only re-sort the buffer.
  ;; Would that be useful?  Re-re-sorting is easy, too.
  (if (consp buffer-undo-list)
      (setq buffer-undo-list nil))
  (let ((buffer-undo-list t)
        ;; If point is on a field, we try to return point to that field.
        ;; Otherwise we try to return to the same column
        (old-pos (let ((pid (proced-pid-at-point))
                       (key (get-text-property (point) 'proced-key)))
                   (list pid key ; can both be nil
                         (if key
                             (if (get-text-property (1- (point)) 'proced-key)
                                 (- (point) (previous-single-property-change
                                             (point) 'proced-key))
                               0)
                           (current-column)))))
        buffer-read-only mp-list)
    ;; remember marked processes (whatever the mark was)
    (goto-char (point-min))
    (while (re-search-forward "^\\(\\S-\\)" nil t)
      (push (cons (save-match-data (proced-pid-at-point))
                  (match-string-no-properties 1)) mp-list))

    ;; generate listing
    (erase-buffer)
    (proced-format proced-process-alist proced-format)
    (goto-char (point-min))
    (while (not (eobp))
      (insert "  ")
      (forward-line))
    (setq proced-header-line (concat "  " proced-header-line))
    (if revert (set-buffer-modified-p nil))

    ;; set `goal-column'
    (let ((grammar (assq proced-goal-attribute proced-grammar-alist)))
      (setq goal-column ;; set to nil if no match
            (if (and grammar
                     (not (zerop (buffer-size)))
                     (string-match (regexp-quote (nth 1 grammar))
                                   proced-header-line))
                (if (nth 3 grammar)
                    (match-beginning 0)
                  (match-end 0)))))

    ;; Restore process marks and buffer position (if possible).
    ;; Sometimes this puts point in the middle of the proced buffer
    ;; where it is not interesting.  Is there a better / more flexible solution?
    (goto-char (point-min))
    (let (pid mark new-pos)
      (if (or mp-list (car old-pos))
          (while (not (eobp))
            (setq pid (proced-pid-at-point))
            (when (setq mark (assq pid mp-list))
              (insert (cdr mark))
              (delete-char 1)
              (beginning-of-line))
            (when (eq (car old-pos) pid)
              (if (nth 1 old-pos)
                  (let ((limit (line-end-position)) pos)
                    (while (and (not new-pos)
                                (setq pos (next-property-change (point) nil limit)))
                      (goto-char pos)
                      (when (eq (nth 1 old-pos)
                                (get-text-property (point) 'proced-key))
                        (forward-char (min (nth 2 old-pos)
                                           (- (next-property-change (point))
                                              (point))))
                        (setq new-pos (point))))
                    (unless new-pos
                      ;; we found the process, but the field of point
                      ;; is not listed anymore
                      (setq new-pos (proced-move-to-goal-column))))
                (setq new-pos (min (+ (line-beginning-position) (nth 2 old-pos))
                                   (line-end-position)))))
            (forward-line)))
      (if new-pos
          (goto-char new-pos)
        (goto-char (point-min))
        (proced-move-to-goal-column)))
    ;; update modeline
    ;; Does the long `mode-name' clutter the modeline?  It would be nice
    ;; to have some other location for displaying the values of the various
    ;; flags that affect the behavior of proced (flags one might want
    ;; to change on the fly).  Where??
    (setq mode-name
          (concat "Proced"
                  (if proced-filter
                      (concat ": " (symbol-name proced-filter))
                    "")
                  (if proced-sort
                      (let* ((key (if (consp proced-sort) (car proced-sort)
                                    proced-sort))
                             (grammar (assq key proced-grammar-alist)))
                        (concat " by " (if proced-descend "-" "+")
                                (nth 1 grammar)))
                    "")))
    (force-mode-line-update)
    ;; run `proced-post-display-hook' only for a displayed buffer.
    (if (get-buffer-window) (run-hooks 'proced-post-display-hook))
    ;; done
    (or quiet (input-pending-p)
        (message (if revert "Updating process information...done."
                   "Updating process display...done.")))))

(defun proced-revert (&rest _args)
  "Reevaluate the process listing based on the currently running processes.
Preserves point and marks."
  (proced-update t))

(defun proced-send-signal (&optional signal)
  "Send a SIGNAL to the marked processes.
If no process is marked, operate on current process.
SIGNAL may be a string (HUP, INT, TERM, etc.) or a number.
If SIGNAL is nil display marked processes and query interactively for SIGNAL.
After sending the signal, this command runs the normal hook
`proced-after-send-signal-hook'."
  (interactive)
  (let ((regexp (proced-marker-regexp))
        process-alist)
    ;; collect marked processes
    (save-excursion
      (goto-char (point-min))
      (while (re-search-forward regexp nil t)
        (push (cons (proced-pid-at-point)
                    ;; How much info should we collect here?
                    (buffer-substring-no-properties
                     (+ 2 (line-beginning-position))
                     (line-end-position)))
              process-alist)))
    (setq process-alist
          (if process-alist
              (nreverse process-alist)
            ;; take current process
            (list (cons (proced-pid-at-point)
                        (buffer-substring-no-properties
                         (+ 2 (line-beginning-position))
                         (line-end-position))))))
    (unless signal
      ;; Display marked processes (code taken from `dired-mark-pop-up').
      (let ((bufname  " *Marked Processes*") ; use leading space in buffer name
					; to make this buffer ephemeral
            (header-line (substring-no-properties proced-header-line)))
        (with-current-buffer (get-buffer-create bufname)
          (setq truncate-lines t
                proced-header-line header-line ; inherit header line
                header-line-format '(:eval (proced-header-line)))
          (add-hook 'post-command-hook 'force-mode-line-update nil t)
          (let ((inhibit-read-only t))
            (erase-buffer)
            (buffer-disable-undo)
            (setq buffer-read-only t)
            (dolist (process process-alist)
              (insert "  " (cdr process) "\n"))
            (delete-char -1)
            (goto-char (point-min)))
          (save-window-excursion
            ;; Analogous to `dired-pop-to-buffer'
            ;; Don't split window horizontally.  (Bug#1806)
            (let (split-width-threshold)
              (pop-to-buffer (current-buffer)))
            (fit-window-to-buffer (get-buffer-window) nil 1)
            (let* ((completion-ignore-case t)
                   (pnum (if (= 1 (length process-alist))
                             "1 process"
                           (format "%d processes" (length process-alist))))
                   (completion-extra-properties
                    '(:annotation-function
                      (lambda (s) (cdr (assoc s proced-signal-list))))))
              (setq signal
                    (completing-read (concat "Send signal [" pnum
                                             "] (default TERM): ")
                                     proced-signal-list
                                     nil nil nil nil "TERM")))))))
    ;; send signal
    (let ((count 0)
          failures)
      ;; Why not always use `signal-process'?  See
      ;; http://lists.gnu.org/archive/html/emacs-devel/2008-03/msg02955.html
      (if (functionp proced-signal-function)
          ;; use built-in `signal-process'
          (let ((signal (if (stringp signal)
                            (if (string-match "\\`[0-9]+\\'" signal)
                                (string-to-number signal)
                              (make-symbol signal))
                          signal)))   ; number
            (dolist (process process-alist)
              (condition-case err
                  (if (zerop (funcall
                              proced-signal-function (car process) signal))
                      (setq count (1+ count))
                    (proced-log "%s\n" (cdr process))
                    (push (cdr process) failures))
                (error ; catch errors from failed signals
                 (proced-log "%s\n" err)
                 (proced-log "%s\n" (cdr process))
                 (push (cdr process) failures)))))
        ;; use external system call
        (let ((signal (concat "-" (if (numberp signal)
                                      (number-to-string signal) signal))))
          (dolist (process process-alist)
            (with-temp-buffer
              (condition-case nil
                  (if (zerop (call-process
                              proced-signal-function nil t nil
                              signal (number-to-string (car process))))
                      (setq count (1+ count))
                    (proced-log (current-buffer))
                    (proced-log "%s\n" (cdr process))
                    (push (cdr process) failures))
                (error ; catch errors from failed signals
                 (proced-log (current-buffer))
                 (proced-log "%s\n" (cdr process))
                 (push (cdr process) failures)))))))
      (if failures
          ;; Proced error message are not always very precise.
          ;; Can we issue a useful one-line summary in the
          ;; message area (using FAILURES) if only one signal failed?
          (proced-log-summary
           signal
           (format "%d of %d signal%s failed"
                   (length failures) (length process-alist)
                   (if (= 1 (length process-alist)) "" "s")))
        (proced-success-message "Sent signal to" count)))
    ;; final clean-up
    (run-hooks 'proced-after-send-signal-hook)))

;; similar to `dired-why'
(defun proced-why ()
  "Pop up a buffer with error log output from Proced.
A group of errors from a single command ends with a formfeed.
Thus, use \\[backward-page] to find the beginning of a group of errors."
  (interactive)
  (if (get-buffer proced-log-buffer)
      (save-selected-window
        ;; move `proced-log-buffer' to the front of the buffer list
        (select-window (display-buffer (get-buffer proced-log-buffer)))
        (setq truncate-lines t)
        (set-buffer-modified-p nil)
        (setq buffer-read-only t)
        (goto-char (point-max))
        (forward-line -1)
        (backward-page 1)
        (recenter 0))))

;; similar to `dired-log'
(defun proced-log (log &rest args)
  "Log a message or the contents of a buffer.
If LOG is a string and there are more args, it is formatted with
those ARGS.  Usually the LOG string ends with a \\n.
End each bunch of errors with (proced-log t signal):
this inserts the current time, buffer and signal at the start of the page,
and \f (formfeed) at the end."
  (let ((obuf (current-buffer)))
    (with-current-buffer (get-buffer-create proced-log-buffer)
      (goto-char (point-max))
      (let (buffer-read-only)
	(cond ((stringp log)
	       (insert (if args
			   (apply 'format log args)
			 log)))
	      ((bufferp log)
	       (insert-buffer-substring log))
	      ((eq t log)
	       (backward-page 1)
	       (unless (bolp)
		 (insert "\n"))
	       (insert (current-time-string)
		       "\tBuffer `" (buffer-name obuf) "', "
                       (format "signal `%s'\n" (car args)))
	       (goto-char (point-max))
	       (insert "\f\n")))))))

;; similar to `dired-log-summary'
(defun proced-log-summary (signal string)
  "State a summary of SIGNAL's failures, in echo area and log buffer.
STRING is an overall summary of the failures."
  (message "Signal %s: %s--type ? for details" signal string)
  ;; Log a summary describing a bunch of errors.
  (proced-log (concat "\n" string "\n"))
  (proced-log t signal))

(defun proced-help ()
  "Provide help for the Proced user."
  (interactive)
  (proced-why)
  (if (eq last-command 'proced-help)
      (describe-mode)
    (message proced-help-string)))

(defun proced-undo ()
  "Undo in a Proced buffer.
This doesn't recover killed processes, it just undoes changes in the Proced
buffer.  You can use it to recover marks."
  (interactive)
  (let (buffer-read-only)
    (undo))
  (message "Change in Proced buffer undone.
Killed processes cannot be recovered by Emacs."))

(provide 'proced)

;;; proced.el ends here