Branch
Hash :
7b089321
Author :
Date :
2025-01-01T09:24:36
maint: run 'make update-copyright'
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
# isapipe.m4
# serial 1
dnl Copyright (C) 2006, 2009-2025 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.
dnl This file is offered as-is, without any warranty.
# Test whether a file descriptor is a pipe.
dnl Written by Paul Eggert.
AC_DEFUN([gl_ISAPIPE],
[
# OpenVMS has isapipe already, so check for it.
AC_CHECK_FUNCS([isapipe])
if test $ac_cv_func_isapipe = yes; then
HAVE_ISAPIPE=1
else
HAVE_ISAPIPE=0
fi
])
# Prerequisites of lib/isapipe.c.
AC_DEFUN([gl_PREREQ_ISAPIPE],
[
AC_CACHE_CHECK([whether pipes are FIFOs (and for their link count)],
[gl_cv_pipes_are_fifos],
[AC_RUN_IFELSE(
[AC_LANG_SOURCE(
[[#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#ifndef S_ISFIFO
#define S_ISFIFO(m) 0
#endif
#ifndef S_ISSOCK
#define S_ISSOCK(m) 0
#endif
int
main (int argc, char **argv)
{
int fd[2];
struct stat st;
if (pipe (fd) != 0)
return 1;
if (fstat (fd[0], &st) != 0)
return 2;
if (2 <= argc && argv[1][0] == '-')
{
char const *yesno = (S_ISFIFO (st.st_mode) ? "yes" : "no");
if (st.st_nlink <= 1)
{
long int i = st.st_nlink;
if (i != st.st_nlink)
return 3;
printf ("%s (%ld)\n", yesno, i);
}
else
{
unsigned long int i = st.st_nlink;
if (i != st.st_nlink)
return 4;
printf ("%s (%lu)\n", yesno, i);
}
}
else
{
if (! S_ISFIFO (st.st_mode) && ! S_ISSOCK (st.st_mode))
return 5;
}
return 0;
}]])],
[gl_cv_pipes_are_fifos=`./conftest$ac_exeext -`
test -z "$gl_cv_pipes_are_fifos" && gl_cv_pipes_are_fifos=no],
[gl_cv_pipes_are_fifos=unknown],
[gl_cv_pipes_are_fifos=cross-compiling])])
case $gl_cv_pipes_are_fifos in #(
'yes ('*')')
AC_DEFINE([HAVE_FIFO_PIPES], [1],
[Define to 1 if pipes are FIFOs, 0 if sockets. Leave undefined
if not known.]);; #(
'no ('*')')
AC_DEFINE([HAVE_FIFO_PIPES], [0]);;
esac
case $gl_cv_pipes_are_fifos in #(
*'('*')')
AC_DEFINE_UNQUOTED([PIPE_LINK_COUNT_MAX],
[`expr "$gl_cv_pipes_are_fifos" : '.*\((.*)\)'`],
[Define to the maximum link count that a true pipe can have.]);;
esac
])