ls.c revision aa2106b008921ed8f33ee14ee70fb1b944f547ec 
1#include <stdio.h>
2#include <stdlib.h>
3#include <string.h>
4#include <sys/types.h>
5#include <dirent.h>
6#include <errno.h>
7
8#include <sys/stat.h>
9#include <unistd.h>
10#include <time.h>
11
12#include <pwd.h>
13#include <grp.h>
14
15#include <linux/kdev_t.h>
16#include <limits.h>
17
18// dynamic arrays
19typedef struct {
20    int count;
21    int capacity;
22    void** items;
23} dynarray_t;
24
25#define DYNARRAY_INITIALIZER  { 0, 0, NULL }
26
27static void dynarray_init( dynarray_t *a )
28{
29    a->count = a->capacity = 0;
30    a->items = NULL;
31}
32
33static void dynarray_reserve_more( dynarray_t *a, int count )
34{
35    int old_cap = a->capacity;
36    int new_cap = old_cap;
37    const int max_cap = INT_MAX/sizeof(void*);
38    void** new_items;
39    int new_count = a->count + count;
40
41    if (count <= 0)
42        return;
43
44    if (count > max_cap - a->count)
45        abort();
46
47    new_count = a->count + count;
48
49    while (new_cap < new_count) {
50        old_cap = new_cap;
51        new_cap += (new_cap >> 2) + 4;
52        if (new_cap < old_cap || new_cap > max_cap) {
53            new_cap = max_cap;
54        }
55    }
56    new_items = realloc(a->items, new_cap*sizeof(void*));
57    if (new_items == NULL)
58        abort();
59
60    a->items = new_items;
61    a->capacity = new_cap;
62}
63
64static void dynarray_append( dynarray_t *a, void* item )
65{
66    if (a->count >= a->capacity)
67        dynarray_reserve_more(a, 1);
68
69    a->items[a->count++] = item;
70}
71
72static void dynarray_done( dynarray_t *a )
73{
74    free(a->items);
75    a->items = NULL;
76    a->count = a->capacity = 0;
77}
78
79#define DYNARRAY_FOREACH_TYPE(_array,_item_type,_item,_stmnt) \
80    do { \
81        int _nn_##__LINE__ = 0; \
82        for (;_nn_##__LINE__ < (_array)->count; ++ _nn_##__LINE__) { \
83            _item_type _item = (_item_type)(_array)->items[_nn_##__LINE__]; \
84            _stmnt; \
85        } \
86    } while (0)
87
88#define DYNARRAY_FOREACH(_array,_item,_stmnt) \
89    DYNARRAY_FOREACH_TYPE(_array,void *,_item,_stmnt)
90
91// string arrays
92
93typedef dynarray_t  strlist_t;
94
95#define  STRLIST_INITIALIZER  DYNARRAY_INITIALIZER
96
97#define  STRLIST_FOREACH(_list,_string,_stmnt) \
98    DYNARRAY_FOREACH_TYPE(_list,char *,_string,_stmnt)
99
100static void strlist_init( strlist_t *list )
101{
102    dynarray_init(list);
103}
104
105static void strlist_append_b( strlist_t *list, const void* str, size_t  slen )
106{
107    char *copy = malloc(slen+1);
108    memcpy(copy, str, slen);
109    copy[slen] = '\0';
110    dynarray_append(list, copy);
111}
112
113static void strlist_append_dup( strlist_t *list, const char *str)
114{
115    strlist_append_b(list, str, strlen(str));
116}
117
118static void strlist_done( strlist_t *list )
119{
120    STRLIST_FOREACH(list, string, free(string));
121    dynarray_done(list);
122}
123
124static int strlist_compare_strings(const void* a, const void* b)
125{
126    const char *sa = *(const char **)a;
127    const char *sb = *(const char **)b;
128    return strcmp(sa, sb);
129}
130
131static void strlist_sort( strlist_t *list )
132{
133    if (list->count > 0) {
134        qsort(list->items,
135              (size_t)list->count,
136              sizeof(void*),
137              strlist_compare_strings);
138    }
139}
140
141// bits for flags argument
142#define LIST_LONG           (1 << 0)
143#define LIST_ALL            (1 << 1)
144#define LIST_RECURSIVE      (1 << 2)
145#define LIST_DIRECTORIES    (1 << 3)
146#define LIST_SIZE           (1 << 4)
147
148// fwd
149static int listpath(const char *name, int flags);
150
151static char mode2kind(unsigned mode)
152{
153    switch(mode & S_IFMT){
154    case S_IFSOCK: return 's';
155    case S_IFLNK: return 'l';
156    case S_IFREG: return '-';
157    case S_IFDIR: return 'd';
158    case S_IFBLK: return 'b';
159    case S_IFCHR: return 'c';
160    case S_IFIFO: return 'p';
161    default: return '?';
162    }
163}
164
165static void mode2str(unsigned mode, char *out)
166{
167    *out++ = mode2kind(mode);
168
169    *out++ = (mode & 0400) ? 'r' : '-';
170    *out++ = (mode & 0200) ? 'w' : '-';
171    if(mode & 04000) {
172        *out++ = (mode & 0100) ? 's' : 'S';
173    } else {
174        *out++ = (mode & 0100) ? 'x' : '-';
175    }
176    *out++ = (mode & 040) ? 'r' : '-';
177    *out++ = (mode & 020) ? 'w' : '-';
178    if(mode & 02000) {
179        *out++ = (mode & 010) ? 's' : 'S';
180    } else {
181        *out++ = (mode & 010) ? 'x' : '-';
182    }
183    *out++ = (mode & 04) ? 'r' : '-';
184    *out++ = (mode & 02) ? 'w' : '-';
185    if(mode & 01000) {
186        *out++ = (mode & 01) ? 't' : 'T';
187    } else {
188        *out++ = (mode & 01) ? 'x' : '-';
189    }
190    *out = 0;
191}
192
193static void user2str(unsigned uid, char *out)
194{
195    struct passwd *pw = getpwuid(uid);
196    if(pw) {
197        strcpy(out, pw->pw_name);
198    } else {
199        sprintf(out, "%d", uid);
200    }
201}
202
203static void group2str(unsigned gid, char *out)
204{
205    struct group *gr = getgrgid(gid);
206    if(gr) {
207        strcpy(out, gr->gr_name);
208    } else {
209        sprintf(out, "%d", gid);
210    }
211}
212
213static int listfile_size(const char *path, int flags)
214{
215    struct stat s;
216
217    if (lstat(path, &s) < 0)
218        return -1;
219
220    /* blocks are 512 bytes, we want output to be KB */
221    printf("%lld %s\n", s.st_blocks / 2, path);
222    return 0;
223}
224
225static int listfile_long(const char *path, int flags)
226{
227    struct stat s;
228    char date[32];
229    char mode[16];
230    char user[16];
231    char group[16];
232    const char *name;
233
234    /* name is anything after the final '/', or the whole path if none*/
235    name = strrchr(path, '/');
236    if(name == 0) {
237        name = path;
238    } else {
239        name++;
240    }
241
242    if(lstat(path, &s) < 0) {
243        return -1;
244    }
245
246    mode2str(s.st_mode, mode);
247    user2str(s.st_uid, user);
248    group2str(s.st_gid, group);
249
250    strftime(date, 32, "%Y-%m-%d %H:%M", localtime((const time_t*)&s.st_mtime));
251    date[31] = 0;
252
253// 12345678901234567890123456789012345678901234567890123456789012345678901234567890
254// MMMMMMMM UUUUUUUU GGGGGGGGG XXXXXXXX YYYY-MM-DD HH:MM NAME (->LINK)
255
256    switch(s.st_mode & S_IFMT) {
257    case S_IFBLK:
258    case S_IFCHR:
259        printf("%s %-8s %-8s %3d, %3d %s %s\n",
260               mode, user, group,
261               (int) MAJOR(s.st_rdev), (int) MINOR(s.st_rdev),
262               date, name);
263        break;
264    case S_IFREG:
265        printf("%s %-8s %-8s %8d %s %s\n",
266               mode, user, group, (int) s.st_size, date, name);
267        break;
268    case S_IFLNK: {
269        char linkto[256];
270        int len;
271
272        len = readlink(path, linkto, 256);
273        if(len < 0) return -1;
274
275        if(len > 255) {
276            linkto[252] = '.';
277            linkto[253] = '.';
278            linkto[254] = '.';
279            linkto[255] = 0;
280        } else {
281            linkto[len] = 0;
282        }
283
284        printf("%s %-8s %-8s          %s %s -> %s\n",
285               mode, user, group, date, name, linkto);
286        break;
287    }
288    default:
289        printf("%s %-8s %-8s          %s %s\n",
290               mode, user, group, date, name);
291
292    }
293    return 0;
294}
295
296static int listfile(const char *dirname, const char *filename, int flags)
297{
298    if ((flags & (LIST_LONG | LIST_SIZE)) == 0) {
299        printf("%s\n", filename);
300        return 0;
301    }
302
303    char tmp[4096];
304    const char* pathname = filename;
305
306    if (dirname != NULL) {
307        snprintf(tmp, sizeof(tmp), "%s/%s", dirname, filename);
308        pathname = tmp;
309    } else {
310        pathname = filename;
311    }
312
313    if ((flags & LIST_LONG) != 0) {
314        return listfile_long(pathname, flags);
315    } else /*((flags & LIST_SIZE) != 0)*/ {
316        return listfile_size(pathname, flags);
317    }
318}
319
320static int listdir(const char *name, int flags)
321{
322    char tmp[4096];
323    DIR *d;
324    struct dirent *de;
325    strlist_t  files = STRLIST_INITIALIZER;
326
327    d = opendir(name);
328    if(d == 0) {
329        fprintf(stderr, "opendir failed, %s\n", strerror(errno));
330        return -1;
331    }
332
333    while((de = readdir(d)) != 0){
334        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) continue;
335        if(de->d_name[0] == '.' && (flags & LIST_ALL) == 0) continue;
336
337        strlist_append_dup(&files, de->d_name);
338    }
339
340    strlist_sort(&files);
341    STRLIST_FOREACH(&files, filename, listfile(name, filename, flags));
342    strlist_done(&files);
343
344    if (flags & LIST_RECURSIVE) {
345        strlist_t subdirs = STRLIST_INITIALIZER;
346
347        rewinddir(d);
348
349        while ((de = readdir(d)) != 0) {
350            struct stat s;
351            int err;
352
353            if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
354                continue;
355            if (de->d_name[0] == '.' && (flags & LIST_ALL) == 0)
356                continue;
357
358            if (!strcmp(name, "/"))
359                snprintf(tmp, sizeof(tmp), "/%s", de->d_name);
360            else
361                snprintf(tmp, sizeof(tmp), "%s/%s", name, de->d_name);
362
363            /*
364             * If the name ends in a '/', use stat() so we treat it like a
365             * directory even if it's a symlink.
366             */
367            if (tmp[strlen(tmp)-1] == '/')
368                err = stat(tmp, &s);
369            else
370                err = lstat(tmp, &s);
371
372            if (err < 0) {
373                perror(tmp);
374                closedir(d);
375                return -1;
376            }
377
378            if (S_ISDIR(s.st_mode)) {
379                strlist_append_dup(&subdirs, tmp);
380            }
381        }
382        strlist_sort(&subdirs);
383        STRLIST_FOREACH(&subdirs, path, {
384            printf("\n%s:\n", path);
385            listdir(path, flags);
386        });
387        strlist_done(&subdirs);
388    }
389
390    closedir(d);
391    return 0;
392}
393
394static int listpath(const char *name, int flags)
395{
396    struct stat s;
397    int err;
398
399    /*
400     * If the name ends in a '/', use stat() so we treat it like a
401     * directory even if it's a symlink.
402     */
403    if (name[strlen(name)-1] == '/')
404        err = stat(name, &s);
405    else
406        err = lstat(name, &s);
407
408    if (err < 0) {
409        perror(name);
410        return -1;
411    }
412
413    if ((flags & LIST_DIRECTORIES) == 0 && S_ISDIR(s.st_mode)) {
414        if (flags & LIST_RECURSIVE)
415            printf("\n%s:\n", name);
416        return listdir(name, flags);
417    } else {
418        /* yeah this calls stat() again*/
419        return listfile(NULL, name, flags);
420    }
421}
422
423int ls_main(int argc, char **argv)
424{
425    int flags = 0;
426    int listed = 0;
427
428    if(argc > 1) {
429        int i;
430        int err = 0;
431        strlist_t  files = STRLIST_INITIALIZER;
432
433        for (i = 1; i < argc; i++) {
434            if (argv[i][0] == '-') {
435                /* an option ? */
436                const char *arg = argv[i]+1;
437                while (arg[0]) {
438                    switch (arg[0]) {
439                    case 'l': flags |= LIST_LONG; break;
440                    case 's': flags |= LIST_SIZE; break;
441                    case 'R': flags |= LIST_RECURSIVE; break;
442                    case 'd': flags |= LIST_DIRECTORIES; break;
443                    case 'a': flags |= LIST_ALL; break;
444                    default:
445                        fprintf(stderr, "%s: Unknown option '-%c'. Aborting.\n", "ls", arg[0]);
446                        exit(1);
447                    }
448                    arg++;
449                }
450            } else {
451                /* not an option ? */
452                strlist_append_dup(&files, argv[i]);
453            }
454        }
455
456        if (files.count > 0) {
457            STRLIST_FOREACH(&files, path, {
458                if (listpath(path, flags) != 0) {
459                    err = EXIT_FAILURE;
460                }
461            });
462            strlist_done(&files);
463            return err;
464        }
465    }
466
467    // list working directory if no files or directories were specified
468    return listpath(".", flags);
469}
470