[root@rhel74 clang]# cat ls.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
static void do_ls(char *path);
int
main(int argc, char *argv[])
{
int i;
if (argc < 2) {
fprintf(stderr, "%s: no arguments\n", argv[0]);
exit(1);
}
for (i = 1; i < argc; i++) {
do_ls(argv[i]);
}
exit(0);
}
static void
do_ls(char *path)
{
DIR *d;
struct dirent *ent;
d = opendir(path); /* (1) */
if (!d) {
perror(path);
exit(1);
}
while (ent = readdir(d)) { /* (2) */
printf("%s\n", ent->d_name);
}
closedir(d); /* (1') */
}
[root@rhel74 clang]# ./ls /tmp
.
..
.XIM-unix
.font-unix
.X11-unix
.ICE-unix
.Test-unix
yum_save_tx.2019-12-02.23-55.oirlkk.yumtx
systemd-private-b3fd831bc3a2402bb120c9d7ebf65706-chronyd.service-SwasY6
[root@rhel74 clang]# cat mkdir.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
int
main(int argc, char *argv[])
{
int i;
if (argc < 2) {
fprintf(stderr, "%s: no arguments\n", argv[0]);
exit(1);
}
for (i = 1; i < argc; i++) {
if (mkdir(argv[i], 0777) < 0) {
perror(argv[i]);
exit(1);
}
}
exit(0);
}
[root@rhel74 clang]# ./mkdir x y z
[root@rhel74 clang]# ls -ld x y z
drwxr-xr-x 2 root root 6 12月 3 00:37 x
drwxr-xr-x 2 root root 6 12月 3 00:37 y
drwxr-xr-x 2 root root 6 12月 3 00:37 z
[root@rhel74 clang]# cat rmdir.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
int i;
if (argc < 2) {
fprintf(stderr, "%s: no arguments\n", argv[0]);
exit(1);
}
for (i = 1; i < argc; i++) {
if (rmdir(argv[i]) < 0) {
perror(argv[i]);
exit(1);
}
}
exit(0);
}
[root@rhel74 clang]# ./rmdir x y z
[root@rhel74 clang]# cat rm.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
int i;
if (argc < 2) {
fprintf(stderr, "%s: no arguments\n", argv[0]);
exit(1);
}
for (i = 1; i < argc; i++) {
if (unlink(argv[i]) < 0) {
perror(argv[i]);
exit(1);
}
}
exit(0);
}
[root@rhel74 clang]# touch aaa
[root@rhel74 clang]# ./rm aaa
[root@rhel74 clang]# cat ln.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
if (argc != 3) {
fprintf(stderr, "%s: wrong arguments\n", argv[0]);
exit(1);
}
if (link(argv[1], argv[2]) < 0) {
perror(argv[1]);
exit(1);
}
exit(0);
}
[root@rhel74 clang]# cat mv.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
if (argc != 3) {
fprintf(stderr, "%s: wrong arguments\n", argv[0]);
exit(1);
}
if (rename(argv[1], argv[2]) < 0) {
perror(argv[1]);
exit(1);
}
exit(0);
}
[root@rhel74 clang]# cat symlink.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
if (argc != 3) {
fprintf(stderr, "%s: wrong number of arguments\n", argv[0]);
exit(1);
}
if (symlink(argv[1], argv[2]) < 0) {
perror(argv[1]);
exit(1);
}
exit(0);
}
[root@rhel74 clang]# cat stat.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
static char *filetype(mode_t mode);
int
main(int argc, char *argv[])
{
struct stat st;
if (argc != 2) {
fprintf(stderr, "wrong argument\n");
exit(1);
}
if (lstat(argv[1], &st) < 0) {
perror(argv[1]);
exit(1);
}
printf("type\t%o (%s)\n", (st.st_mode & S_IFMT), filetype(st.st_mode));
printf("mode\t%o\n", st.st_mode & ~S_IFMT);
printf("dev\t%llu\n", (unsigned long long)st.st_dev);
printf("ino\t%lu\n", (unsigned long)st.st_ino);
printf("rdev\t%llu\n", (unsigned long long)st.st_rdev);
printf("nlink\t%lu\n", (unsigned long)st.st_nlink);
printf("uid\t%d\n", st.st_uid);
printf("gid\t%d\n", st.st_gid);
printf("size\t%ld\n", st.st_size);
printf("blksize\t%lu\n", (unsigned long)st.st_blksize);
printf("blocks\t%lu\n", (unsigned long)st.st_blocks);
printf("atime\t%s", ctime(&st.st_atime));
printf("mtime\t%s", ctime(&st.st_mtime));
printf("ctime\t%s", ctime(&st.st_ctime));
exit(0);
}
static char*
filetype(mode_t mode)
{
if (S_ISREG(mode)) return "file";
if (S_ISDIR(mode)) return "directory";
if (S_ISCHR(mode)) return "chardev";
if (S_ISBLK(mode)) return "blockdev";
if (S_ISFIFO(mode)) return "fifo";
if (S_ISLNK(mode)) return "symlink";
if (S_ISSOCK(mode)) return "socket";
return "unknown";
}
[root@rhel74 clang]# ./stat stat.c
type 100000 (file)
mode 644
dev 64768
ino 17535598
rdev 0
nlink 1
uid 0
gid 0
size 1447
blksize 4096
blocks 8
atime Wed Dec 4 00:05:20 2019
mtime Wed Dec 4 00:05:04 2019
ctime Wed Dec 4 00:05:04 2019