1/* closeout.c - close standard output 2 3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software 4 Foundation, Inc. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software Foundation, 18 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 19 20#if HAVE_CONFIG_H 21# include <config.h> 22#endif 23 24#include "closeout.h" 25 26#include <stdio.h> 27#include <errno.h> 28 29#include "gettext.h" 30#define _(msgid) gettext (msgid) 31 32#include "error.h" 33#include "exitfail.h" 34#include "quotearg.h" 35#include "unlocked-io.h" 36#include "__fpending.h" 37 38static const char *file_name; 39 40/* Set the file name to be reported in the event an error is detected 41 by close_stdout. */ 42void 43close_stdout_set_file_name (const char *file) 44{ 45 file_name = file; 46} 47 48/* Close standard output, exiting with status 'exit_failure' on failure. 49 If a program writes *anything* to stdout, that program should `fflush' 50 stdout and make sure that it succeeds before exiting. Otherwise, 51 suppose that you go to the extreme of checking the return status 52 of every function that does an explicit write to stdout. The last 53 printf can succeed in writing to the internal stream buffer, and yet 54 the fclose(stdout) could still fail (due e.g., to a disk full error) 55 when it tries to write out that buffered data. Thus, you would be 56 left with an incomplete output file and the offending program would 57 exit successfully. 58 59 FIXME: note the fflush suggested above is implicit in the fclose 60 we actually do below. Consider doing only the fflush and/or using 61 setvbuf to inhibit buffering. 62 63 Besides, it's wasteful to check the return value from every call 64 that writes to stdout -- just let the internal stream state record 65 the failure. That's what the ferror test is checking below. 66 67 It's important to detect such failures and exit nonzero because many 68 tools (most notably `make' and other build-management systems) depend 69 on being able to detect failure in other tools via their exit status. */ 70 71void 72close_stdout (void) 73{ 74 int e = ferror (stdout) ? 0 : -1; 75 76 /* If the stream's error bit is clear and there is nothing to flush, 77 then return right away. */ 78 if (e && __fpending (stdout) == 0) 79 return; 80 81 if (fclose (stdout) != 0) 82 e = errno; 83 84 if (0 <= e) 85 { 86 char const *write_error = _("write error"); 87 if (file_name) 88 error (exit_failure, e, "%s: %s", quotearg_colon (file_name), 89 write_error); 90 else 91 error (exit_failure, e, "%s", write_error); 92 } 93} 94