| # pwrite.m4 serial 5 |
| dnl Copyright (C) 2010-2020 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_PWRITE], |
| [ |
| AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) |
| AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| |
| dnl Persuade glibc <unistd.h> to declare pwrite(). |
| AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) |
| |
| AC_CHECK_FUNCS_ONCE([pwrite]) |
| if test $ac_cv_func_pwrite = yes; then |
| dnl On HP-UX 11.11 with _FILE_OFFSET_BITS=64, pwrite() on a file does not |
| dnl fail when an invalid (negative) offset is passed and uses an arbitrary |
| dnl offset instead of the argument. |
| AC_CACHE_CHECK([whether pwrite works], |
| [gl_cv_func_pwrite_works], |
| [ |
| dnl Initial guess, used when cross-compiling. |
| changequote(,)dnl |
| case "$host_os" in |
| # Guess no on HP-UX. |
| hpux*) gl_cv_func_pwrite_works="guessing no" ;; |
| # Guess yes otherwise. |
| *) gl_cv_func_pwrite_works="guessing yes" ;; |
| esac |
| changequote([,])dnl |
| gl_save_CPPFLAGS="$CPPFLAGS" |
| CPPFLAGS="$CPPFLAGS -D_FILE_OFFSET_BITS=64" |
| rm -f conftest.out |
| AC_RUN_IFELSE( |
| [AC_LANG_PROGRAM([[ |
| #include <sys/types.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| ]], |
| [[ |
| { |
| /* This test fails on HP-UX 11.00..11.11. */ |
| { |
| int fd = open ("conftest.out", O_RDWR | O_CREAT | O_TRUNC, 0600); |
| if (fd < 0) |
| return 1; |
| if (pwrite (fd, "b", 1, (off_t) -1) >= 0) |
| return 2; |
| } |
| /* This test fails on HP-UX 11.00..11.11. */ |
| { |
| int fd; |
| char buf[] = "01"; |
| |
| fd = open ("conftest.out", O_WRONLY | O_CREAT | O_TRUNC, 0600); |
| if (fd < 0) |
| return 3; |
| if (write (fd, buf, 2) < 2) |
| return 4; |
| if (close (fd) < 0) |
| return 5; |
| |
| fd = open ("conftest.out", O_WRONLY, 0600); |
| if (fd < 0) |
| return 6; |
| if (pwrite (fd, "W", 1, (off_t) 0) != 1) |
| return 7; |
| if (close (fd) < 0) |
| return 8; |
| |
| fd = open ("conftest.out", O_RDONLY); |
| if (fd < 0) |
| return 9; |
| if (read (fd, buf, 2) < 2) |
| return 10; |
| if (close (fd) < 0) |
| return 11; |
| if (buf[0] != 'W') |
| return 12; |
| if (buf[1] != '1') |
| return 13; |
| } |
| return 0; |
| }]])], |
| [gl_cv_func_pwrite_works=yes], |
| [gl_cv_func_pwrite_works=no], |
| [:]) |
| rm -f conftest.out |
| CPPFLAGS="$gl_save_CPPFLAGS" |
| ]) |
| case "$gl_cv_func_pwrite_works" in |
| *yes) ;; |
| *) REPLACE_PWRITE=1 ;; |
| esac |
| else |
| HAVE_PWRITE=0 |
| fi |
| ]) |