Mercurial > gnulib
view m4/getdtablesize.m4 @ 40153:878ddb87671b
mountlist: Merge two .m4 files.
* m4/mountlist.m4 (gl_MOUNTLIST): Inline gl_LIST_MOUNTED_FILE_SYSTEMS.
(AC_FUNC_GETMNTENT): Move to here, from m4/ls-mntd-fs.m4.
* m4/ls-mntd-fs.m4: Remove file.
* modules/mountlist (Files): Remove m4/ls-mntd-fs.m4.
author | Bruno Haible <bruno@clisp.org> |
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date | Sun, 27 Jan 2019 11:45:28 +0100 |
parents | b06060465f09 |
children |
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# getdtablesize.m4 serial 7 dnl Copyright (C) 2008-2019 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. AC_DEFUN([gl_FUNC_GETDTABLESIZE], [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) AC_REQUIRE([AC_CANONICAL_HOST]) AC_CHECK_FUNCS_ONCE([getdtablesize]) AC_CHECK_DECLS_ONCE([getdtablesize]) if test $ac_cv_func_getdtablesize = yes && test $ac_cv_have_decl_getdtablesize = yes; then AC_CACHE_CHECK([whether getdtablesize works], [gl_cv_func_getdtablesize_works], [dnl There are two concepts: the "maximum possible file descriptor value + 1" dnl and the "maximum number of open file descriptors in a process". dnl Per SUSv2 and POSIX, getdtablesize() should return the first one. dnl On most platforms, the first and the second concept are the same. dnl On OpenVMS, however, they are different and getdtablesize() returns dnl the second one; thus the test below fails. But we don't care dnl because there's no good way to write a replacement getdtablesize(). case "$host_os" in vms*) gl_cv_func_getdtablesize_works="no (limitation)" ;; *) dnl Cygwin 1.7.25 automatically increases the RLIMIT_NOFILE soft dnl limit up to an unchangeable hard limit; all other platforms dnl correctly require setrlimit before getdtablesize() can report dnl a larger value. AC_RUN_IFELSE([ AC_LANG_PROGRAM([[#include <unistd.h>]], [int size = getdtablesize(); if (dup2 (0, getdtablesize()) != -1) return 1; if (size != getdtablesize()) return 2; ])], [gl_cv_func_getdtablesize_works=yes], [gl_cv_func_getdtablesize_works=no], [case "$host_os" in cygwin*) # on cygwin 1.5.25, getdtablesize() automatically grows gl_cv_func_getdtablesize_works="guessing no" ;; *) gl_cv_func_getdtablesize_works="guessing yes" ;; esac ]) ;; esac ]) case "$gl_cv_func_getdtablesize_works" in *yes | "no (limitation)") ;; *) REPLACE_GETDTABLESIZE=1 ;; esac else HAVE_GETDTABLESIZE=0 fi ]) # Prerequisites of lib/getdtablesize.c. AC_DEFUN([gl_PREREQ_GETDTABLESIZE], [:])