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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:46:38 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:46:38 +0000 |
commit | a06ac93dcf311dac3943cb5d96ad47625d413c2d (patch) | |
tree | 6efda5e24896e7920ccac1f97aecc73406525040 /m4/isapipe.m4 | |
parent | Initial commit. (diff) | |
download | coreutils-upstream.tar.xz coreutils-upstream.zip |
Adding upstream version 8.30.upstream/8.30upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'm4/isapipe.m4')
-rw-r--r-- | m4/isapipe.m4 | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/m4/isapipe.m4 b/m4/isapipe.m4 new file mode 100644 index 0000000..a85109b --- /dev/null +++ b/m4/isapipe.m4 @@ -0,0 +1,93 @@ +# Test whether a file descriptor is a pipe. + +dnl Copyright (C) 2006, 2009-2018 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 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 +]) |