mirror of
https://github.com/sheumann/hush.git
synced 2024-11-04 14:05:24 +00:00
105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* *printf implementations for busybox
|
|
*
|
|
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
/* Mar 12, 2003 Manuel Novoa III
|
|
*
|
|
* While fwrite(), fputc(), fputs(), etc. all set the stream error flag
|
|
* on failure, the *printf functions are unique in that they can fail
|
|
* for reasons not related to the actual output itself. Among the possible
|
|
* reasons for failure which don't set the streams error indicator,
|
|
* SUSv3 lists EILSEQ, EINVAL, and ENOMEM.
|
|
*
|
|
* In some cases, it would be desirable to have a group of *printf()
|
|
* functions available that _always_ set the stream error indicator on
|
|
* failure. That would allow us to defer error checking until applet
|
|
* exit. Unfortunately, there is no standard way of setting a streams
|
|
* error indicator... even though we can clear it with clearerr().
|
|
*/
|
|
|
|
/* Mar 22, 2006 Rich Felker III
|
|
*
|
|
* Actually there is a portable way to set the error indicator. See below.
|
|
* It is not thread-safe as written due to a race condition with file
|
|
* descriptors but since BB is not threaded that does not matter. It can be
|
|
* made thread-safe at the expense of slightly more code, if this is ever
|
|
* needed in the future.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdarg.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include "libbb.h"
|
|
|
|
#ifdef L_bb_vfprintf
|
|
int bb_vfprintf(FILE * __restrict stream,
|
|
const char * __restrict format,
|
|
va_list arg)
|
|
{
|
|
int rv;
|
|
|
|
if ((rv = vfprintf(stream, format, arg)) < 0) {
|
|
/* The following sequence portably sets the error flag for
|
|
* stream on any remotely POSIX-compliant implementation. */
|
|
|
|
int errno_save = errno;
|
|
int fd = fileno(stream);
|
|
int tmp = dup(fd);
|
|
|
|
fflush(stream);
|
|
close(fd);
|
|
/* Force an attempted write to nonexistant fd => EBADF */
|
|
fputc(0, stream);
|
|
fflush(stream);
|
|
/* Restore the stream's original fd */
|
|
dup2(tmp, fd);
|
|
close(tmp);
|
|
errno = errno_save;
|
|
}
|
|
|
|
return rv;
|
|
}
|
|
#endif
|
|
|
|
#ifdef L_bb_vprintf
|
|
int bb_vprintf(const char * __restrict format, va_list arg)
|
|
{
|
|
return bb_vfprintf(stdout, format, arg);
|
|
}
|
|
#endif
|
|
|
|
#ifdef L_bb_fprintf
|
|
int bb_fprintf(FILE * __restrict stream,
|
|
const char * __restrict format, ...)
|
|
{
|
|
va_list arg;
|
|
int rv;
|
|
|
|
va_start(arg, format);
|
|
rv = bb_vfprintf(stream, format, arg);
|
|
va_end(arg);
|
|
|
|
return rv;
|
|
}
|
|
#endif
|
|
|
|
#ifdef L_bb_printf
|
|
int bb_printf(const char * __restrict format, ...)
|
|
{
|
|
va_list arg;
|
|
int rv;
|
|
|
|
va_start(arg, format);
|
|
rv = bb_vfprintf(stdout, format, arg);
|
|
va_end(arg);
|
|
|
|
return rv;
|
|
}
|
|
#endif
|