99 lines
1.9 KiB
C
Executable file
99 lines
1.9 KiB
C
Executable file
/*
|
|
* freopen.c - open a file and associate a stream with it
|
|
*/
|
|
/* $Header$ */
|
|
|
|
#if defined(_POSIX_SOURCE)
|
|
#include <sys/types.h>
|
|
#endif
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include "loc_incl.h"
|
|
|
|
#define PMODE 0666
|
|
|
|
/* Do not "optimize" this file to use the open with O_CREAT if the file
|
|
* does not exist. The reason is given in fopen.c.
|
|
*/
|
|
#define O_RDONLY 0
|
|
#define O_WRONLY 1
|
|
#define O_RDWR 2
|
|
|
|
#define O_CREAT 0x010
|
|
#define O_TRUNC 0x020
|
|
#define O_APPEND 0x040
|
|
|
|
int _open(const char *path, int flags);
|
|
int _creat(const char *path, _mnx_Mode_t mode);
|
|
int _close(int d);
|
|
|
|
FILE *
|
|
freopen(const char *name, const char *mode, FILE *stream)
|
|
{
|
|
register int i;
|
|
int rwmode = 0, rwflags = 0;
|
|
int fd, flags = stream->_flags & (_IONBF | _IOFBF | _IOLBF | _IOMYBUF);
|
|
|
|
(void) fflush(stream); /* ignore errors */
|
|
(void) _close(fileno(stream));
|
|
|
|
switch(*mode++) {
|
|
case 'r':
|
|
flags |= _IOREAD;
|
|
rwmode = O_RDONLY;
|
|
break;
|
|
case 'w':
|
|
flags |= _IOWRITE;
|
|
rwmode = O_WRONLY;
|
|
rwflags = O_CREAT | O_TRUNC;
|
|
break;
|
|
case 'a':
|
|
flags |= _IOWRITE | _IOAPPEND;
|
|
rwmode = O_WRONLY;
|
|
rwflags |= O_APPEND | O_CREAT;
|
|
break;
|
|
default:
|
|
return (FILE *)NULL;
|
|
}
|
|
|
|
while (*mode) {
|
|
switch(*mode++) {
|
|
case 'b':
|
|
continue;
|
|
case '+':
|
|
rwmode = O_RDWR;
|
|
flags |= _IOREAD | _IOWRITE;
|
|
continue;
|
|
/* The sequence may be followed by aditional characters */
|
|
default:
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if ((rwflags & O_TRUNC)
|
|
|| (((fd = _open(name, rwmode)) < 0)
|
|
&& (rwflags & O_CREAT))) {
|
|
if (((fd = _creat(name, PMODE)) < 0) && flags | _IOREAD) {
|
|
(void) _close(fd);
|
|
fd = _open(name, rwmode);
|
|
}
|
|
}
|
|
|
|
if (fd < 0) {
|
|
for( i = 0; i < FOPEN_MAX; i++) {
|
|
if (stream == __iotab[i]) {
|
|
__iotab[i] = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (stream != stdin && stream != stdout && stream != stderr)
|
|
free((void *)stream);
|
|
return (FILE *)NULL;
|
|
}
|
|
|
|
stream->_count = 0;
|
|
stream->_fd = fd;
|
|
stream->_flags = flags;
|
|
return stream;
|
|
}
|