micro-utils/coreutils/chown.c
2023-10-29 12:27:44 +03:00

175 lines
3.2 KiB
C

#include <pwd.h>
#include <grp.h>
#include <stdio.h>
#include <errno.h>
#include <dirent.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
unsigned int r_flag;
int (*chown_func)(const char *pathname, uid_t owner, gid_t group);
int (*stat_func)(const char *restrict pathname, struct stat *restrict statbuf);
long gid;
long uid;
int get_stat(const char *path, struct stat *stat_path) {
if (stat_func(path, stat_path)) {
fprintf(stderr, "chown: unable to stat %s: %s\n", path, strerror(errno));
return 1;
}
return 0;
}
char *make_path(const char *src, const char *dst) {
size_t len = strlen(src) + strlen(dst) + 2;
char *full_path = malloc(len + 1);
if (full_path == NULL) {
fprintf(stderr, "chown: malloc() returned NULL\n");
return NULL;
}
snprintf(full_path, len, "%s/%s", src, dst);
return full_path;
}
int change(const char *file) {
struct stat old_file;
if (get_stat(file, &old_file))
return 1;
if (chown_func(file, uid, gid) == 0) {
struct stat new_file;
if (get_stat(file, &new_file))
return 1;
if (old_file.st_gid != new_file.st_gid || old_file.st_uid != new_file.st_uid)
return 0;
fprintf(stderr, "chown: %s unchanged\n", file);
}
else
fprintf(stderr, "chown: unable to chown %s: %s\n", file, strerror(errno));
return 1;
}
int cntree(const char *dst) {
int ret = change(dst);
struct stat stat_path;
if (get_stat(dst, &stat_path))
return 1;
if (!S_ISDIR(stat_path.st_mode) || !r_flag)
return ret;
DIR *dir = opendir(dst);
if (dir == NULL) {
fprintf(stderr, "chown: %s: Can`t open directory\n", dst);
return 1;
}
struct dirent *ep;
while ((ep = readdir(dir)) != NULL) {
if (!strcmp(ep->d_name, ".") || !strcmp(ep->d_name, ".."))
continue;
char *full_path = make_path(dst, ep->d_name);
if (full_path == NULL)
continue;
if (cntree(full_path))
ret = 1;
free(full_path);
}
closedir(dir);
return ret;
}
void get_owner(const char *arg) {
char *group = strchr(arg, ':');
unsigned int g_flag = 1;
unsigned int u_flag = 1;
if (group == arg)
u_flag = 0;
else if (!group)
g_flag = 0;
if (g_flag) {
group[0] = '\0';
group++;
struct group *grp = getgrnam(group);
if (!grp) {
fprintf(stderr, "chown: invalid group: %s\n", group);
exit(1);
}
gid = grp->gr_gid;
}
if (u_flag) {
struct passwd *pwd = getpwnam(arg);
if (!pwd) {
fprintf(stderr, "chown: invalid user: %s\n", arg);
exit(1);
}
uid = pwd->pw_gid;
}
}
int main(const int argc, char **argv) {
chown_func = lchown;
stat_func = stat;
int i;
for (i = 1; i < argc; i++) {
if (argv[i][0] != '-')
break;
else if (!strcmp(argv[i], "-r"))
r_flag = 1;
else if (!strcmp(argv[i], "-H")) {
chown_func = chown;
stat_func = stat;
}
else if (!strcmp(argv[i], "--help")) {
printf("chown [-H (if a command line argument is a symbolic link)] [-r (recursive)] [owner]:[group] [file file2...]\n");
return 0;
}
}
if (argc - i == 0) {
fprintf(stderr, "chown: missing operand\n");
return 1;
}
gid = -1;
uid = -1;
get_owner(argv[i++]);
if (argc - i == 0) {
fprintf(stderr, "chown: missing operand\n");
return 1;
}
int ret = 0;
for (; i < argc; i++)
if (cntree(argv[i]))
ret = 1;
return ret;
}