close-stream.c

Absolute File Name:

/home/opencoverage/opencoverage/guest-scripts/coreutils/src/gnulib/lib/close-stream.c

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/* Close a stream, with nicer error checking than fclose's.

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 3 of the License, 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, see <https://www.gnu.org/licenses/>. */

#include <config.h>

#include "close-stream.h"

#include <errno.h>

#include <stdbool.h>

#include "fpending.h"

#if USE_UNLOCKED_IO

# include "unlocked-io.h"

#endif

/* Close STREAM. Return 0 if successful, EOF (setting errno)

otherwise. A failure might set errno to 0 if the error number

cannot be determined.

A failure with errno set to EPIPE may or may not indicate an error

situation worth signaling to the user. See the documentation of the

close_stdout_set_ignore_EPIPE function for details.

If a program writes *anything* to STREAM, that program should close

STREAM 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 STREAM. The last

printf can succeed in writing to the internal stream buffer, and yet

the fclose(STREAM) 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. Even calling fflush is not always sufficient,

since some file systems (NFS and CODA) buffer written/flushed data

until an actual close call.

Besides, it's wasteful to check the return value from every call

that writes to STREAM -- just let the internal stream state record

the failure. That's what the ferror test is checking below. */

int

close_stream (FILE *stream)

{

const bool some_pending = (__fpending (stream) != 0);

const bool prev_fail = (ferror (stream) != 0);

const bool fclose_fail = (fclose (stream) != 0);

/* Return an error indication if there was a previous failure or if

fclose failed, with one exception: ignore an fclose failure if

there was no previous error, no data remains to be flushed, and

fclose failed with EBADF. That can happen when a program like cp

is invoked like this 'cp a b >&-' (i.e., with standard output

closed) and doesn't generate any output (hence no previous error

and nothing to be flushed). */

if (prev_fail || (fclose_fail && (some_pending || errno != EBADF)))

prev_fail	Description
TRUE	never evaluated
FALSE	evaluated 78835 times by 106 tests Evaluated by: [ b2sum base32 base64 basename cat chcon chgrp chmod chown chroot cksum comm cp csplit cut date dd df dir dircolors dirname du echo env ...

fclose_fail	Description
TRUE	evaluated 28 times by 15 tests Evaluated by: chmod cp dd ln mkdir mktemp mv printf rm rmdir sleep tail test timeout touch
FALSE	evaluated 78807 times by 106 tests Evaluated by: [ b2sum base32 base64 basename cat chcon chgrp chmod chown chroot cksum comm cp csplit cut date dd df dir dircolors dirname du echo env ...

some_pending	Description
TRUE	evaluated 4 times by 1 test Evaluated by: mktemp
FALSE	evaluated 24 times by 14 tests Evaluated by: chmod cp dd ln mkdir mv printf rm rmdir sleep tail test timeout touch

(*__errno_location ()) != 9	Description
TRUE	never evaluated
FALSE	evaluated 24 times by 14 tests Evaluated by: chmod cp dd ln mkdir mv printf rm rmdir sleep tail test timeout touch

0-78835

{

if (! fclose_fail)

! fclose_fail	Description
TRUE	never evaluated
FALSE	evaluated 4 times by 1 test Evaluated by: mktemp

0-4

errno = 0;

never executed: (*__errno_location ()) = 0;

return EOF;

executed 4 times by 1 test: return (-1) ;

Executed by:

mktemp

}

return 0;

executed 78831 times by 106 tests: return 0;

Executed by:

[
b2sum
base32
base64
basename
cat
chcon
chgrp
chmod
chown
chroot
cksum
comm
cp
csplit
cut
date
dd
df
dir
dircolors
dirname
du
echo
env
...

78831

}

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