diff options
Diffstat (limited to 'm4/lseek.m4')
| -rw-r--r-- | m4/lseek.m4 | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/m4/lseek.m4 b/m4/lseek.m4 new file mode 100644 index 00000000..f6452f6f --- /dev/null +++ b/m4/lseek.m4 @@ -0,0 +1,49 @@ +# lseek.m4 serial 6 +dnl Copyright (C) 2007, 2009-2011 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_LSEEK], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + AC_REQUIRE([AC_PROG_CC]) + AC_CACHE_CHECK([whether lseek detects pipes], [gl_cv_func_lseek_pipe], + [if test $cross_compiling = no; then + AC_LINK_IFELSE([AC_LANG_PROGRAM([[ +#include <sys/types.h> /* for off_t */ +#include <stdio.h> /* for SEEK_CUR */ +#include <unistd.h>]], [[ + /* Exit with success only if stdin is seekable. */ + return lseek (0, (off_t)0, SEEK_CUR) < 0; +]])], + [if test -s conftest$ac_exeext \ + && ./conftest$ac_exeext < conftest.$ac_ext \ + && test 1 = "`echo hi \ + | { ./conftest$ac_exeext; echo $?; cat >/dev/null; }`"; then + gl_cv_func_lseek_pipe=yes + else + gl_cv_func_lseek_pipe=no + fi], + [gl_cv_func_lseek_pipe=no]) + else + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#if ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) || defined __BEOS__ +/* mingw and BeOS mistakenly return 0 when trying to seek on pipes. */ + Choke me. +#endif]])], + [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no]) + fi]) + if test $gl_cv_func_lseek_pipe = no; then + gl_REPLACE_LSEEK + fi +]) + +AC_DEFUN([gl_REPLACE_LSEEK], +[ + AC_LIBOBJ([lseek]) + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + REPLACE_LSEEK=1 + AC_DEFINE([LSEEK_PIPE_BROKEN], [1], + [Define to 1 if lseek does not detect pipes.]) +]) |