procps/lib/fileutils.c

#include <errno.h>
#ifdef HAVE_ERROR_H
# include <error.h>
#endif
#ifdef HAVE_STDIO_EXT_H
# include <stdio_ext.h>
#else
/* FIXME: use a more portable definition of __fpending() (from gnulib?) */
# include <stdio.h>
# define __fpending(fp) ((fp)->_p - (fp)->_bf._base)
#endif
#include <stdlib.h>
#include <unistd.h>

#include "nls.h"
#include "fileutils.h"
#ifndef HAVE_ERROR_H
# include "c.h" /* for error() emulation */
#endif

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 != EPIPE)
			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 */