cpython-withatomic / Python / dup2.c

The branch 'legacy-trunk' does not exist.
 * Public domain dup2() lookalike
 * by Curtis Jackson @ AT&T Technologies, Burlington, NC
 * electronic address:  burl!rcj
 * dup2 performs the following functions:
 * Check to make sure that fd1 is a valid open file descriptor.
 * Check to see if fd2 is already open; if so, close it.
 * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.
 * Return fd2 if all went well; return BADEXIT otherwise.

#include <fcntl.h>

#define BADEXIT -1

dup2(fd1, fd2)
int fd1, fd2;
	if (fd1 != fd2) {
		if (fcntl(fd1, F_GETFL) < 0)
			return BADEXIT;
		if (fcntl(fd2, F_GETFL) >= 0)
		if (fcntl(fd1, F_DUPFD, fd2) < 0)
			return BADEXIT;
	return fd2;
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.