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caf8a9b2 PE |
1 | #serial 18 |
2 | dnl Copyright (C) 2002, 2005, 2007, 2009-2012 Free Software Foundation, Inc. | |
7a7ef429 PE |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | AC_DEFUN([gl_FUNC_DUP2], | |
8 | [ | |
9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) | |
10 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
11 | m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [ | |
12 | AC_CHECK_FUNCS_ONCE([dup2]) | |
13 | if test $ac_cv_func_dup2 = no; then | |
14 | HAVE_DUP2=0 | |
7a7ef429 PE |
15 | fi |
16 | ], [ | |
17 | AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.]) | |
18 | ]) | |
19 | if test $HAVE_DUP2 = 1; then | |
20 | AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], | |
21 | [AC_RUN_IFELSE([ | |
22 | AC_LANG_PROGRAM([[#include <unistd.h> | |
23 | #include <fcntl.h> | |
24 | #include <errno.h>]], | |
25 | [int result = 0; | |
26 | #ifdef FD_CLOEXEC | |
27 | if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) | |
28 | result |= 1; | |
29 | #endif | |
30 | if (dup2 (1, 1) == 0) | |
31 | result |= 2; | |
32 | #ifdef FD_CLOEXEC | |
33 | if (fcntl (1, F_GETFD) != FD_CLOEXEC) | |
34 | result |= 4; | |
35 | #endif | |
36 | close (0); | |
37 | if (dup2 (0, 0) != -1) | |
38 | result |= 8; | |
39 | /* Many gnulib modules require POSIX conformance of EBADF. */ | |
40 | if (dup2 (2, 1000000) == -1 && errno != EBADF) | |
41 | result |= 16; | |
42 | return result; | |
43 | ]) | |
44 | ], | |
45 | [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], | |
46 | [case "$host_os" in | |
47 | mingw*) # on this platform, dup2 always returns 0 for success | |
caf8a9b2 | 48 | gl_cv_func_dup2_works="guessing no" ;; |
7a7ef429 | 49 | cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 |
caf8a9b2 | 50 | gl_cv_func_dup2_works="guessing no" ;; |
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51 | linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a |
52 | # closed fd may yield -EBADF instead of -1 / errno=EBADF. | |
caf8a9b2 | 53 | gl_cv_func_dup2_works="guessing no" ;; |
7a7ef429 | 54 | freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF. |
caf8a9b2 | 55 | gl_cv_func_dup2_works="guessing no" ;; |
7a7ef429 | 56 | haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. |
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57 | gl_cv_func_dup2_works="guessing no" ;; |
58 | *) gl_cv_func_dup2_works="guessing yes" ;; | |
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59 | esac]) |
60 | ]) | |
caf8a9b2 PE |
61 | case "$gl_cv_func_dup2_works" in |
62 | *yes) ;; | |
63 | *) | |
64 | REPLACE_DUP2=1 | |
65 | ;; | |
66 | esac | |
7a7ef429 | 67 | fi |
54020294 PE |
68 | dnl Replace dup2() for supporting the gnulib-defined fchdir() function, |
69 | dnl to keep fchdir's bookkeeping up-to-date. | |
70 | m4_ifdef([gl_FUNC_FCHDIR], [ | |
71 | gl_TEST_FCHDIR | |
72 | if test $HAVE_FCHDIR = 0; then | |
caf8a9b2 PE |
73 | if test $HAVE_DUP2 = 1; then |
74 | REPLACE_DUP2=1 | |
75 | fi | |
54020294 PE |
76 | fi |
77 | ]) | |
7a7ef429 | 78 | ]) |
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79 | |
80 | # Prerequisites of lib/dup2.c. | |
81 | AC_DEFUN([gl_PREREQ_DUP2], []) |