blob: f8bfe1399992a9b09270b4b9e631b122d99e0dff [file] [log] [blame]
/*
* Portable xxxat() functions.
*
* No copyright is claimed. This code is in the public domain; do with
* it what you wish.
*
* Written by Karel Zak <kzak@redhat.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include "at.h"
#include "c.h"
#ifdef HAVE_FSTATAT
int fstat_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *filename, struct stat *st, int nofollow)
{
return fstatat(dir, filename, st,
nofollow ? AT_SYMLINK_NOFOLLOW : 0);
}
#else
int fstat_at(int dir, const char *dirname, const char *filename,
struct stat *st, int nofollow)
{
if (*filename != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, filename);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return nofollow ? lstat(path, st) : stat(path, st);
}
return nofollow ? lstat(filename, st) : stat(filename, st);
}
#endif
#ifdef HAVE_FSTATAT
int open_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *filename, int flags)
{
return openat(dir, filename, flags);
}
#else
int open_at(int dir, const char *dirname, const char *filename, int flags)
{
if (*filename != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, filename);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return open(path, flags);
}
return open(filename, flags);
}
#endif
FILE *fopen_at(int dir, const char *dirname, const char *filename, int flags,
const char *mode)
{
int fd = open_at(dir, dirname, filename, flags);
if (fd < 0)
return NULL;
return fdopen(fd, mode);
}
#ifdef HAVE_FSTATAT
ssize_t readlink_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *pathname, char *buf, size_t bufsiz)
{
return readlinkat(dir, pathname, buf, bufsiz);
}
#else
ssize_t readlink_at(int dir, const char *dirname, const char *pathname,
char *buf, size_t bufsiz)
{
if (*pathname != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, pathname);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return readlink(path, buf, bufsiz);
}
return readlink(pathname, buf, bufsiz);
}
#endif
#ifdef TEST_PROGRAM_AT
#include <errno.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
int main(int argc, char *argv[])
{
DIR *dir;
struct dirent *d;
char *dirname;
if (argc != 2) {
fprintf(stderr, "usage: %s <directory>\n", argv[0]);
exit(EXIT_FAILURE);
}
dirname = argv[1];
dir = opendir(dirname);
if (!dir)
err(EXIT_FAILURE, "cannot open %s", dirname);
while ((d = readdir(dir))) {
struct stat st;
FILE *f;
printf("%32s ", d->d_name);
if (fstat_at(dirfd(dir), dirname, d->d_name, &st, 0) == 0)
printf("%16jd bytes ", st.st_size);
else
printf("%16s bytes ", "???");
f = fopen_at(dirfd(dir), dirname, d->d_name, O_RDONLY, "r");
printf(" %s\n", f ? "OK" : strerror(errno));
if (f)
fclose(f);
}
closedir(dir);
return EXIT_SUCCESS;
}
#endif