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author | Lorry Tar Creator <lorry-tar-importer@lorry> | 2016-01-20 10:55:18 +0000 |
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committer | Lorry Tar Creator <lorry-tar-importer@lorry> | 2016-01-20 10:55:18 +0000 |
commit | 70e9163c9c18e995515598085cb824e554eb7ae7 (patch) | |
tree | a42dc8b2a6c031354bf31472de888bfc8a060132 /m4/dup2.m4 | |
parent | cbf5993c43f49281173f185863577d86bfac6eae (diff) | |
download | coreutils-tarball-70e9163c9c18e995515598085cb824e554eb7ae7.tar.gz |
coreutils-8.25HEADcoreutils-8.25master
Diffstat (limited to 'm4/dup2.m4')
-rw-r--r-- | m4/dup2.m4 | 114 |
1 files changed, 108 insertions, 6 deletions
@@ -1,5 +1,5 @@ -#serial 5 -dnl Copyright (C) 2002, 2005, 2007 Free Software Foundation, Inc. +#serial 25 +dnl Copyright (C) 2002, 2005, 2007, 2009-2016 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. @@ -7,9 +7,111 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_DUP2], [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) - AC_CHECK_FUNCS_ONCE([dup2]) - if test $ac_cv_func_dup2 = no; then - HAVE_DUP2=0 - AC_LIBOBJ([dup2]) + AC_REQUIRE([AC_CANONICAL_HOST]) + m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [ + AC_CHECK_FUNCS_ONCE([dup2]) + if test $ac_cv_func_dup2 = no; then + HAVE_DUP2=0 + fi + ], [ + AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.]) + ]) + if test $HAVE_DUP2 = 1; then + AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], + [AC_RUN_IFELSE([ + AC_LANG_PROGRAM( + [[#include <errno.h> + #include <fcntl.h> + #include <limits.h> + #include <sys/resource.h> + #include <unistd.h> + #ifndef RLIM_SAVED_CUR + # define RLIM_SAVED_CUR RLIM_INFINITY + #endif + #ifndef RLIM_SAVED_MAX + # define RLIM_SAVED_MAX RLIM_INFINITY + #endif + ]], + [[int result = 0; + int bad_fd = INT_MAX; + struct rlimit rlim; + if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 + && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX + && rlim.rlim_cur != RLIM_INFINITY + && rlim.rlim_cur != RLIM_SAVED_MAX + && rlim.rlim_cur != RLIM_SAVED_CUR) + bad_fd = rlim.rlim_cur; + #ifdef FD_CLOEXEC + if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) + result |= 1; + #endif + if (dup2 (1, 1) != 1) + result |= 2; + #ifdef FD_CLOEXEC + if (fcntl (1, F_GETFD) != FD_CLOEXEC) + result |= 4; + #endif + close (0); + if (dup2 (0, 0) != -1) + result |= 8; + /* Many gnulib modules require POSIX conformance of EBADF. */ + if (dup2 (2, bad_fd) == -1 && errno != EBADF) + result |= 16; + /* Flush out some cygwin core dumps. */ + if (dup2 (2, -1) != -1 || errno != EBADF) + result |= 32; + dup2 (2, 255); + dup2 (2, 256); + /* On OS/2 kLIBC, dup2() does not work on a directory fd. */ + { + int fd = open (".", O_RDONLY); + if (fd == -1) + result |= 64; + else if (dup2 (fd, fd + 1) == -1) + result |= 128; + + close (fd); + } + return result;]]) + ], + [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], + [case "$host_os" in + mingw*) # on this platform, dup2 always returns 0 for success + gl_cv_func_dup2_works="guessing no" ;; + cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 + gl_cv_func_dup2_works="guessing no" ;; + aix* | freebsd*) + # on AIX 7.1 and FreeBSD 6.1, dup2 (1,toobig) gives EMFILE, + # not EBADF. + gl_cv_func_dup2_works="guessing no" ;; + haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. + gl_cv_func_dup2_works="guessing no" ;; + *-android*) # implemented using dup3(), which fails if oldfd == newfd + gl_cv_func_dup2_works="guessing no" ;; + os2*) # on OS/2 kLIBC, dup2() does not work on a directory fd. + gl_cv_func_dup2_works="guessing no" ;; + *) gl_cv_func_dup2_works="guessing yes" ;; + esac]) + ]) + case "$gl_cv_func_dup2_works" in + *yes) ;; + *) + REPLACE_DUP2=1 + AC_CHECK_FUNCS([setdtablesize]) + ;; + esac fi + dnl Replace dup2() for supporting the gnulib-defined fchdir() function, + dnl to keep fchdir's bookkeeping up-to-date. + m4_ifdef([gl_FUNC_FCHDIR], [ + gl_TEST_FCHDIR + if test $HAVE_FCHDIR = 0; then + if test $HAVE_DUP2 = 1; then + REPLACE_DUP2=1 + fi + fi + ]) ]) + +# Prerequisites of lib/dup2.c. +AC_DEFUN([gl_PREREQ_DUP2], []) |