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Diffstat (limited to 'gnu/usr.bin/grep/closeout.c')
-rw-r--r-- | gnu/usr.bin/grep/closeout.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/gnu/usr.bin/grep/closeout.c b/gnu/usr.bin/grep/closeout.c new file mode 100644 index 000000000000..4fdac32b2e85 --- /dev/null +++ b/gnu/usr.bin/grep/closeout.c @@ -0,0 +1,121 @@ +/* closeout.c - close standard output + Copyright (C) 1998, 1999, 2000, 2001 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 + +#if ENABLE_NLS +# include <libintl.h> +# define _(Text) gettext (Text) +#else +# define _(Text) Text +#endif + +#if HAVE_STDLIB_H +# include <stdlib.h> +#endif +#ifndef EXIT_FAILURE +# define EXIT_FAILURE 1 +#endif + +#include <stdio.h> + +#include <errno.h> +#ifndef errno +extern int errno; +#endif + +#include "closeout.h" +#include "error.h" +#include "quotearg.h" +#if 0 +#include "__fpending.h" +#endif + +static int default_exit_status = EXIT_FAILURE; +static const char *file_name; + +/* Set the value to be used for the exit status when close_stdout is called. + This is useful when it is not convenient to call close_stdout_status, + e.g., when close_stdout is called via atexit. */ +void +close_stdout_set_status (int status) +{ + default_exit_status = status; +} + +/* Set the file name to be reported in the event an error is detected + by close_stdout_status. */ +void +close_stdout_set_file_name (const char *file) +{ + file_name = file; +} + +/* Close standard output, exiting with status STATUS 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_status (int status) +{ + int e = ferror (stdout) ? 0 : -1; + +#if 0 + if (__fpending (stdout) == 0) + return; +#endif + + if (fclose (stdout) != 0) + e = errno; + + if (0 < e) + { + char const *write_error = _("write error"); + if (file_name) + error (status, e, "%s: %s", quotearg_colon (file_name), write_error); + else + error (status, e, "%s", write_error); + } +} + +/* Close standard output, exiting with status EXIT_FAILURE on failure. */ +void +close_stdout (void) +{ + close_stdout_status (default_exit_status); +} |