lib: add fileutils file with stream error checking facility

The close_stream() is copied from GNU lib. Inspiration to do this
is talk by Jim Meyering - Goodbye World! The perils of relying on
output streams in C.

Reference: http://www.irill.org/events/ghm-gnu-hackers-meeting/videos/jim-meyering-goodbye-world-the-perils-of-relying-on-output-streams-in-c
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
This commit is contained in:
Sami Kerola 2012-03-23 11:10:04 +01:00
parent 1462c4e581
commit c7cf98b0e0
8 changed files with 81 additions and 1 deletions

7
include/fileutils.h Normal file
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@ -0,0 +1,7 @@
#ifndef PROCPS_NG_FILEUTILS
#define PROCPS_NG_FILEUTILS
int close_stream(FILE * stream);
void close_stdout(void);
#endif

1
lib/.gitignore vendored
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@ -1,2 +1,3 @@
.dirstamp .dirstamp
test_fileutils
test_strutils test_strutils

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@ -2,6 +2,7 @@ AM_CPPFLAGS = -include $(top_builddir)/config.h -I$(top_srcdir)/include
AM_CPPFLAGS += -DTEST_PROGRAM AM_CPPFLAGS += -DTEST_PROGRAM
noinst_PROGRAMS = test_strutils noinst_PROGRAMS = test_strutils test_fileutils
test_strutils_SOURCES = strutils.c test_strutils_SOURCES = strutils.c
test_fileutils_SOURCES = fileutils.c

43
lib/fileutils.c Normal file
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@ -0,0 +1,43 @@
#include <errno.h>
#include <error.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <unistd.h>
#include "nls.h"
int close_stream(FILE * stream)
{
const int some_pending = (__fpending(stream) != 0);
const int prev_fail = (ferror(stream) != 0);
const int fclose_fail = (fclose(stream) != 0);
if (prev_fail || (fclose_fail && (some_pending || errno != EBADF))) {
if (!fclose_fail)
errno = 0;
return EOF;
}
return 0;
}
/* Use atexit(); */
void close_stdout(void)
{
if (close_stream(stdout) != 0 && !(errno == EPIPE)) {
char const *write_error = _("write error");
error(0, errno, "%s", write_error);
_exit(EXIT_FAILURE);
}
if (close_stream(stderr) != 0)
_exit(EXIT_FAILURE);
}
#ifdef TEST_PROGRAM
#include <stdio.h>
int main(int argc, char *argv[])
{
atexit(close_stdout);
printf("Hello, World!\n");
return EXIT_SUCCESS;
}
#endif /* TEST_PROGRAM */

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@ -34,6 +34,7 @@ EXTRA_DIST = \
global-conf.exp \ global-conf.exp \
free.test/free.exp \ free.test/free.exp \
kill.test/kill.exp \ kill.test/kill.exp \
lib.test/fileutils.exp \
lib.test/strutils.exp \ lib.test/strutils.exp \
pgrep.test/pgrep.exp \ pgrep.test/pgrep.exp \
pkill.test/pkill.exp \ pkill.test/pkill.exp \

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@ -0,0 +1,19 @@
#
# Testsuite for lib/fileutils program
#
set noarg "${topdir}lib/test_fileutils"
set test "without argument"
spawn $noarg
expect_pass "$test" "Hello, World!"
set badfd "${topdir}testsuite/lib.test/fileutils_badfd.sh"
set test "test bad file descriptor"
spawn $badfd
expect_pass "$test" "test_fileutils: write error: Bad file descriptor"
set full "${topdir}testsuite/lib.test/fileutils_full.sh"
set test "test no space left on device"
spawn $full
expect_pass "$test" "test_fileutils: write error: No space left on device"

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@ -0,0 +1,4 @@
#!/bin/sh
BASEDIR=$(dirname ${0})
${BASEDIR}/../../lib/test_fileutils >&-

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@ -0,0 +1,4 @@
#!/bin/sh
BASEDIR=$(dirname ${0})
${BASEDIR}/../../lib/test_fileutils > /dev/full