Mercurial > hg > octave-nkf > gnulib-hg
changeset 1662:096732ffc839
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author | Jim Meyering <jim@meyering.net> |
---|---|
date | Mon, 25 Jan 1999 00:13:36 +0000 |
parents | f3f8922f57bb |
children | 8ae2c5884032 |
files | lib/closeout.c |
diffstat | 1 files changed, 18 insertions(+), 2 deletions(-) [+] |
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--- a/lib/closeout.c +++ b/lib/closeout.c @@ -1,5 +1,5 @@ /* closeout.c - close standard output - Copyright (C) 1998 Free Software Foundation, Inc. + Copyright (C) 1998, 1999 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 @@ -42,7 +42,23 @@ #include "closeout.h" #include "error.h" -/* Close standard output, exiting with status STATUS on failure. */ +/* Close standard output, exiting with status STATUS on failure. + If a program writes *anything* to stdout, that program should close + stdout and make sure that the close succeeds. 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. + + 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) {