mirror of https://github.com/pygos/init.git
55 lines
846 B
C
55 lines
846 B
C
/* SPDX-License-Identifier: ISC */
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
|
|
#include "util.h"
|
|
|
|
FILE *fopenat(int dirfd, const char *filename, const char *mode)
|
|
{
|
|
const char *ptr = mode;
|
|
int fd, flags = 0;
|
|
FILE *fp;
|
|
|
|
switch (*(ptr++)) {
|
|
case 'r':
|
|
flags = O_RDONLY;
|
|
break;
|
|
case 'w':
|
|
flags = O_WRONLY | O_CREAT | O_TRUNC;
|
|
break;
|
|
case 'a':
|
|
flags = O_WRONLY | O_CREAT | O_APPEND;
|
|
break;
|
|
default:
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
|
|
if (*ptr == '+') {
|
|
flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
|
|
++ptr;
|
|
}
|
|
|
|
if (*ptr == 'b')
|
|
++ptr;
|
|
|
|
if (*ptr != '\0') {
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
|
|
fd = openat(dirfd, filename, flags, 0644);
|
|
if (fd == -1)
|
|
return NULL;
|
|
|
|
fp = fdopen(fd, mode);
|
|
if (fp == NULL)
|
|
close(fd);
|
|
|
|
return fp;
|
|
}
|