#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#include <time.h>
#include <pwd.h>
#include <grp.h>
#include <linux/kdev_t.h>
// bits for flags argument
#define LIST_LONG (1 << 0)
#define LIST_ALL (1 << 1)
#define LIST_RECURSIVE (1 << 2)
#define LIST_DIRECTORIES (1 << 3)
#define LIST_SIZE (1 << 4)
// fwd
static int listpath(const char *name, int flags);
static char mode2kind(unsigned mode)
{
switch(mode & S_IFMT){
case S_IFSOCK: return 's';
case S_IFLNK: return 'l';
case S_IFREG: return '-';
case S_IFDIR: return 'd';
case S_IFBLK: return 'b';
case S_IFCHR: return 'c';
case S_IFIFO: return 'p';
default: return '?';
}
}
static void mode2str(unsigned mode, char *out)
{
*out++ = mode2kind(mode);
*out++ = (mode & 0400) ? 'r' : '-';
*out++ = (mode & 0200) ? 'w' : '-';
if(mode & 04000) {
*out++ = (mode & 0100) ? 's' : 'S';
} else {
*out++ = (mode & 0100) ? 'x' : '-';
}
*out++ = (mode & 040) ? 'r' : '-';
*out++ = (mode & 020) ? 'w' : '-';
if(mode & 02000) {
*out++ = (mode & 010) ? 's' : 'S';
} else {
*out++ = (mode & 010) ? 'x' : '-';
}
*out++ = (mode & 04) ? 'r' : '-';
*out++ = (mode & 02) ? 'w' : '-';
if(mode & 01000) {
*out++ = (mode & 01) ? 't' : 'T';
} else {
*out++ = (mode & 01) ? 'x' : '-';
}
*out = 0;
}
static void user2str(unsigned uid, char *out)
{
struct passwd *pw = getpwuid(uid);
if(pw) {
strcpy(out, pw->pw_name);
} else {
sprintf(out, "%d", uid);
}
}
static void group2str(unsigned gid, char *out)
{
struct group *gr = getgrgid(gid);
if(gr) {
strcpy(out, gr->gr_name);
} else {
sprintf(out, "%d", gid);
}
}
static int show_total_size(const char *dirname, DIR *d, int flags)
{
struct dirent *de;
char tmp[1024];
struct stat s;
int sum = 0;
/* run through the directory and sum up the file block sizes */
while ((de = readdir(d)) != 0) {
if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
continue;
if (de->d_name[0] == '.' && (flags & LIST_ALL) == 0)
continue;
if (strcmp(dirname, "/") == 0)
snprintf(tmp, sizeof(tmp), "/%s", de->d_name);
else
snprintf(tmp, sizeof(tmp), "%s/%s", dirname, de->d_name);
if (lstat(tmp, &s) < 0) {
fprintf(stderr, "stat failed on %s: %s\n", tmp, strerror(errno));
rewinddir(d);
return -1;
}
sum += s.st_blocks / 2;
}
printf("total %d\n", sum);
rewinddir(d);
return 0;
}
static int listfile_size(const char *path, const char *filename, int flags)
{
struct stat s;
if (lstat(path, &s) < 0) {
fprintf(stderr, "lstat '%s' failed: %s\n", path, strerror(errno));
return -1;
}
/* blocks are 512 bytes, we want output to be KB */
printf("%lld %s\n", s.st_blocks / 2, filename);
return 0;
}
static int listfile_long(const char *path, int flags)
{
struct stat s;
char date[32];
char mode[16];
char user[16];
char group[16];
const char *name;
/* name is anything after the final '/', or the whole path if none*/
name = strrchr(path, '/');
if(name == 0) {
name = path;
} else {
name++;
}
if(lstat(path, &s) < 0) {
return -1;
}
mode2str(s.st_mode, mode);
user2str(s.st_uid, user);
group2str(s.st_gid, group);
strftime(date, 32, "%Y-%m-%d %H:%M", localtime((const time_t*)&s.st_mtime));
date[31] = 0;
// 12345678901234567890123456789012345678901234567890123456789012345678901234567890
// MMMMMMMM UUUUUUUU GGGGGGGGG XXXXXXXX YYYY-MM-DD HH:MM NAME (->LINK)
switch(s.st_mode & S_IFMT) {
case S_IFBLK:
case S_IFCHR:
printf("%s %-8s %-8s %3d, %3d %s %s\n",
mode, user, group,
(int) MAJOR(s.st_rdev), (int) MINOR(s.st_rdev),
date, name);
break;
case S_IFREG:
printf("%s %-8s %-8s %8d %s %s\n",
mode, user, group, (int) s.st_size, date, name);
break;
case S_IFLNK: {
char linkto[256];
int len;
len = readlink(path, linkto, 256);
if(len < 0) return -1;
if(len > 255) {
linkto[252] = '.';
linkto[253] = '.';
linkto[254] = '.';
linkto[255] = 0;
} else {
linkto[len] = 0;
}
printf("%s %-8s %-8s %s %s -> %s\n",
mode, user, group, date, name, linkto);
break;
}
default:
printf("%s %-8s %-8s %s %s\n",
mode, user, group, date, name);
}
return 0;
}
static int listfile(const char *dirname, const char *filename, int flags)
{
if ((flags & (LIST_LONG | LIST_SIZE)) == 0) {
printf("%s\n", filename);
return 0;
}
char tmp[4096];
const char* pathname = filename;
if (dirname != NULL) {
snprintf(tmp, sizeof(tmp), "%s/%s", dirname, filename);
pathname = tmp;
} else {
pathname = filename;
}
if ((flags & LIST_LONG) != 0) {
return listfile_long(pathname, flags);
} else /*((flags & LIST_SIZE) != 0)*/ {
return listfile_size(pathname, filename, flags);
}
}
static int listdir(const char *name, int flags)
{
char tmp[4096];
DIR *d;
struct dirent *de;
d = opendir(name);
if(d == 0) {
fprintf(stderr, "opendir failed, %s\n", strerror(errno));
return -1;
}
if ((flags & LIST_SIZE) != 0) {
show_total_size(name, d, flags);
}
while((de = readdir(d)) != 0){
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) continue;
if(de->d_name[0] == '.' && (flags & LIST_ALL) == 0) continue;
listfile(name, de->d_name, flags);
}
if (flags & LIST_RECURSIVE) {
rewinddir(d);
while ((de = readdir(d)) != 0) {
struct stat s;
int err;
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
continue;
if (de->d_name[0] == '.' && (flags & LIST_ALL) == 0)
continue;
if (!strcmp(name, "/"))
snprintf(tmp, sizeof(tmp), "/%s", de->d_name);
else
snprintf(tmp, sizeof(tmp), "%s/%s", name, de->d_name);
/*
* If the name ends in a '/', use stat() so we treat it like a
* directory even if it's a symlink.
*/
if (tmp[strlen(tmp)-1] == '/')
err = stat(tmp, &s);
else
err = lstat(tmp, &s);
if (err < 0) {
perror(tmp);
closedir(d);
return -1;
}
if (S_ISDIR(s.st_mode)) {
printf("\n%s:\n", tmp);
listdir(tmp, flags);
}
}
}
closedir(d);
return 0;
}
static int listpath(const char *name, int flags)
{
struct stat s;
int err;
/*
* If the name ends in a '/', use stat() so we treat it like a
* directory even if it's a symlink.
*/
if (name[strlen(name)-1] == '/')
err = stat(name, &s);
else
err = lstat(name, &s);
if (err < 0) {
perror(name);
return -1;
}
if ((flags & LIST_DIRECTORIES) == 0 && S_ISDIR(s.st_mode)) {
if (flags & LIST_RECURSIVE)
printf("\n%s:\n", name);
return listdir(name, flags);
} else {
/* yeah this calls stat() again*/
return listfile(NULL, name, flags);
}
}
int ls_main(int argc, char **argv)
{
int flags = 0;
int listed = 0;
if(argc > 1) {
int i;
int err = 0;
for (i = 1; i < argc; i++) {
if (!strcmp(argv[i], "-l")) {
flags |= LIST_LONG;
} else if (!strcmp(argv[i], "-s")) {
flags |= LIST_SIZE;
} else if (!strcmp(argv[i], "-a")) {
flags |= LIST_ALL;
} else if (!strcmp(argv[i], "-R")) {
flags |= LIST_RECURSIVE;
} else if (!strcmp(argv[i], "-d")) {
flags |= LIST_DIRECTORIES;
} else {
listed++;
if(listpath(argv[i], flags) != 0) {
err = EXIT_FAILURE;
}
}
}
if (listed > 0) return err;
}
// list working directory if no files or directories were specified
return listpath(".", flags);
}