From 381e69eace06d863a3dcd9d9f3a8f61fb449be0b Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Fri, 7 Mar 2008 12:21:37 +0100 Subject: dd: avoid unnecessary, but harmless close_stdout call. * src/dd.c (close_stdout_required): New global. (maybe_close_stdout): New function. (main): Set the global. Reported by Ulrich Drepper in http://bugzilla.redhat.com/436368 --- src/dd.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/dd.c b/src/dd.c index c40d0eec4..0a7b15421 100644 --- a/src/dd.c +++ b/src/dd.c @@ -392,6 +392,25 @@ static char const ebcdic_to_ascii[] = '\070', '\071', '\372', '\373', '\374', '\375', '\376', '\377' }; +/* True if we need to close the standard output *stream*. */ +static bool close_stdout_required = true; + +/* The only reason to close the standard output *stream* is if + parse_long_options fails (as it does for --help or --version). + In any other case, dd uses only the STDOUT_FILENO file descriptor, + and the "cleanup" function calls "close (STDOUT_FILENO)". + Closing the file descriptor and then letting the usual atexit-run + close_stdout function call "fclose (stdout)" would result in a + harmless failure of the close syscall (with errno EBADF). + This function serves solely to avoid the unnecessary close_stdout + call, once parse_long_options has succeeded. */ +static void +maybe_close_stdout (void) +{ + if (close_stdout_required) + close_stdout (); +} + void usage (int status) { @@ -1655,12 +1674,14 @@ main (int argc, char **argv) textdomain (PACKAGE); /* Arrange to close stdout if parse_long_options exits. */ - atexit (close_stdout); + atexit (maybe_close_stdout); page_size = getpagesize (); parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE, VERSION, usage, AUTHORS, (char const *) NULL); + close_stdout_required = false; + if (getopt_long (argc, argv, "", NULL, NULL) != -1) usage (EXIT_FAILURE); -- cgit v1.2.3-70-g09d2