Ruby: missing/dup2.c Source File

Ruby 3.0.5p211 (2022-11-24 revision ba5cf0f7c52d4d35cc6a173c89eda98ceffa2dcf)

dup2.c
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1/*
2 * Public domain dup2() lookalike
3 * by Curtis Jackson @ AT&T Technologies, Burlington, NC
4 * electronic address: burl!rcj
5 *
6 * dup2 performs the following functions:
7 *
8 * Check to make sure that fd1 is a valid open file descriptor.
9 * Check to see if fd2 is already open; if so, close it.
10 * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.
11 * Return fd2 if all went well; return BADEXIT otherwise.
12 */
13
14#include "ruby/internal/config.h"
15
16#if defined(HAVE_FCNTL)
17# include <fcntl.h>
18#endif
19
20#if !defined(HAVE_FCNTL) || !defined(F_DUPFD)
21# include <errno.h>
22#endif
23
24#define BADEXIT -1
25
26int
27 dup2(int fd1, int fd2)
28{
29#if defined(HAVE_FCNTL) && defined(F_DUPFD)
30 if (fd1 != fd2) {
31#ifdef F_GETFL
32 if (fcntl(fd1, F_GETFL) < 0)
33 return BADEXIT;
34 if (fcntl(fd2, F_GETFL) >= 0)
35 close(fd2);
36#else
37 close(fd2);
38#endif
39 if (fcntl(fd1, F_DUPFD, fd2) < 0)
40 return BADEXIT;
41 }
42 return fd2;
43#else
44 extern int errno;
45 int i, fd, fds[256];
46
47 if (fd1 == fd2) return 0;
48 close(fd2);
49 for (i=0; i<256; i++) {
50 fd = fds[i] = dup(fd1);
51 if (fd == fd2) break;
52 }
53 while (i) {
54 close(fds[i--]);
55 }
56 if (fd == fd2) return 0;
57 errno = EMFILE;
58 return BADEXIT;
59#endif
60}
BADEXIT
#define BADEXIT
Definition: dup2.c:24
dup2
int dup2(int fd1, int fd2)
Definition: dup2.c:27
config.h
Thin wrapper to ruby/config.h.
fcntl
int fcntl(int, int,...)
Definition: win32.c:4338
F_DUPFD
#define F_DUPFD
Definition: win32.h:575