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Revision 14514b6e71b6f2c26dc95f45f24e748e72052292 authored by Miss Islington (bot) on 10 September 2019, 16:40:32 UTC, committed by GitHub on 10 September 2019, 16:40:32 UTC 
Docs: Small tweaks to c-api/introGH-Include_Files (GH-14698)
 
(cherry picked from commit b6dafe51399f5c6313a00529118a6052b466942f)

Co-authored-by: Kyle Stanley <aeros167@gmail.com>
1 parent 075a441
Raw File
dup2.c 
/*
 * 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>
#include <unistd.h>

#define BADEXIT -1

int
dup2(int fd1, int fd2)
{
    if (fd1 != fd2) {
        if (fcntl(fd1, F_GETFL) < 0)
            return BADEXIT;
        if (fcntl(fd2, F_GETFL) >= 0)
            close(fd2);
        if (fcntl(fd1, F_DUPFD, fd2) < 0)
            return BADEXIT;
    }
    return fd2;
}
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