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Diffstat (limited to 'lib/closeout.c')
-rw-r--r-- | lib/closeout.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/closeout.c b/lib/closeout.c new file mode 100644 index 0000000000000..3c7bed9c3d556 --- /dev/null +++ b/lib/closeout.c @@ -0,0 +1,93 @@ +/* closeout.c - close standard output + + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software + Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#include "closeout.h" + +#include <stdio.h> +#include <errno.h> + +#include "gettext.h" +#define _(msgid) gettext (msgid) + +#include "error.h" +#include "exitfail.h" +#include "quotearg.h" +#include "unlocked-io.h" +#include "__fpending.h" + +static const char *file_name; + +/* Set the file name to be reported in the event an error is detected + by close_stdout. */ +void +close_stdout_set_file_name (const char *file) +{ + file_name = file; +} + +/* Close standard output, exiting with status 'exit_failure' on failure. + If a program writes *anything* to stdout, that program should `fflush' + stdout and make sure that it succeeds before exiting. Otherwise, + suppose that you go to the extreme of checking the return status + of every function that does an explicit write to stdout. The last + printf can succeed in writing to the internal stream buffer, and yet + the fclose(stdout) could still fail (due e.g., to a disk full error) + when it tries to write out that buffered data. Thus, you would be + left with an incomplete output file and the offending program would + exit successfully. + + FIXME: note the fflush suggested above is implicit in the fclose + we actually do below. Consider doing only the fflush and/or using + setvbuf to inhibit buffering. + + Besides, it's wasteful to check the return value from every call + that writes to stdout -- just let the internal stream state record + the failure. That's what the ferror test is checking below. + + It's important to detect such failures and exit nonzero because many + tools (most notably `make' and other build-management systems) depend + on being able to detect failure in other tools via their exit status. */ + +void +close_stdout (void) +{ + int e = ferror (stdout) ? 0 : -1; + + /* If the stream's error bit is clear and there is nothing to flush, + then return right away. */ + if (e && __fpending (stdout) == 0) + return; + + if (fclose (stdout) != 0) + e = errno; + + if (0 <= e) + { + char const *write_error = _("write error"); + if (file_name) + error (exit_failure, e, "%s: %s", quotearg_colon (file_name), + write_error); + else + error (exit_failure, e, "%s", write_error); + } +} |