ls.c revision 7c84efe083f4cd6b4a322bfe018f26b2f7d1e844 
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 show_total_size(const char *dirname, DIR *d, int flags)
214{
215    struct dirent *de;
216    char tmp[1024];
217    struct stat s;
218    int sum = 0;
219
220    /* run through the directory and sum up the file block sizes */
221    while ((de = readdir(d)) != 0) {
222        if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
223            continue;
224        if (de->d_name[0] == '.' && (flags & LIST_ALL) == 0)
225            continue;
226
227        if (strcmp(dirname, "/") == 0)
228            snprintf(tmp, sizeof(tmp), "/%s", de->d_name);
229        else
230            snprintf(tmp, sizeof(tmp), "%s/%s", dirname, de->d_name);
231
232        if (lstat(tmp, &s) < 0) {
233            fprintf(stderr, "stat failed on %s: %s\n", tmp, strerror(errno));
234            rewinddir(d);
235            return -1;
236        }
237
238        sum += s.st_blocks / 2;
239    }
240
241    printf("total %d\n", sum);
242    rewinddir(d);
243    return 0;
244}
245
246static int listfile_size(const char *path, const char *filename, int flags)
247{
248    struct stat s;
249
250    if (lstat(path, &s) < 0) {
251        fprintf(stderr, "lstat '%s' failed: %s\n", path, strerror(errno));
252        return -1;
253    }
254
255    /* blocks are 512 bytes, we want output to be KB */
256    printf("%lld %s\n", s.st_blocks / 2, filename);
257    return 0;
258}
259
260static int listfile_long(const char *path, int flags)
261{
262    struct stat s;
263    char date[32];
264    char mode[16];
265    char user[16];
266    char group[16];
267    const char *name;
268
269    /* name is anything after the final '/', or the whole path if none*/
270    name = strrchr(path, '/');
271    if(name == 0) {
272        name = path;
273    } else {
274        name++;
275    }
276
277    if(lstat(path, &s) < 0) {
278        return -1;
279    }
280
281    mode2str(s.st_mode, mode);
282    user2str(s.st_uid, user);
283    group2str(s.st_gid, group);
284
285    strftime(date, 32, "%Y-%m-%d %H:%M", localtime((const time_t*)&s.st_mtime));
286    date[31] = 0;
287
288// 12345678901234567890123456789012345678901234567890123456789012345678901234567890
289// MMMMMMMM UUUUUUUU GGGGGGGGG XXXXXXXX YYYY-MM-DD HH:MM NAME (->LINK)
290
291    switch(s.st_mode & S_IFMT) {
292    case S_IFBLK:
293    case S_IFCHR:
294        printf("%s %-8s %-8s %3d, %3d %s %s\n",
295               mode, user, group,
296               (int) MAJOR(s.st_rdev), (int) MINOR(s.st_rdev),
297               date, name);
298        break;
299    case S_IFREG:
300        printf("%s %-8s %-8s %8d %s %s\n",
301               mode, user, group, (int) s.st_size, date, name);
302        break;
303    case S_IFLNK: {
304        char linkto[256];
305        int len;
306
307        len = readlink(path, linkto, 256);
308        if(len < 0) return -1;
309
310        if(len > 255) {
311            linkto[252] = '.';
312            linkto[253] = '.';
313            linkto[254] = '.';
314            linkto[255] = 0;
315        } else {
316            linkto[len] = 0;
317        }
318
319        printf("%s %-8s %-8s          %s %s -> %s\n",
320               mode, user, group, date, name, linkto);
321        break;
322    }
323    default:
324        printf("%s %-8s %-8s          %s %s\n",
325               mode, user, group, date, name);
326
327    }
328    return 0;
329}
330
331static int listfile(const char *dirname, const char *filename, int flags)
332{
333    if ((flags & (LIST_LONG | LIST_SIZE)) == 0) {
334        printf("%s\n", filename);
335        return 0;
336    }
337
338    char tmp[4096];
339    const char* pathname = filename;
340
341    if (dirname != NULL) {
342        snprintf(tmp, sizeof(tmp), "%s/%s", dirname, filename);
343        pathname = tmp;
344    } else {
345        pathname = filename;
346    }
347
348    if ((flags & LIST_LONG) != 0) {
349        return listfile_long(pathname, flags);
350    } else /*((flags & LIST_SIZE) != 0)*/ {
351        return listfile_size(pathname, filename, flags);
352    }
353}
354
355static int listdir(const char *name, int flags)
356{
357    char tmp[4096];
358    DIR *d;
359    struct dirent *de;
360    strlist_t  files = STRLIST_INITIALIZER;
361
362    d = opendir(name);
363    if(d == 0) {
364        fprintf(stderr, "opendir failed, %s\n", strerror(errno));
365        return -1;
366    }
367
368    if ((flags & LIST_SIZE) != 0) {
369        show_total_size(name, d, flags);
370    }
371
372    while((de = readdir(d)) != 0){
373        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) continue;
374        if(de->d_name[0] == '.' && (flags & LIST_ALL) == 0) continue;
375
376        strlist_append_dup(&files, de->d_name);
377    }
378
379    strlist_sort(&files);
380    STRLIST_FOREACH(&files, filename, listfile(name, filename, flags));
381    strlist_done(&files);
382
383    if (flags & LIST_RECURSIVE) {
384        strlist_t subdirs = STRLIST_INITIALIZER;
385
386        rewinddir(d);
387
388        while ((de = readdir(d)) != 0) {
389            struct stat s;
390            int err;
391
392            if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
393                continue;
394            if (de->d_name[0] == '.' && (flags & LIST_ALL) == 0)
395                continue;
396
397            if (!strcmp(name, "/"))
398                snprintf(tmp, sizeof(tmp), "/%s", de->d_name);
399            else
400                snprintf(tmp, sizeof(tmp), "%s/%s", name, de->d_name);
401
402            /*
403             * If the name ends in a '/', use stat() so we treat it like a
404             * directory even if it's a symlink.
405             */
406            if (tmp[strlen(tmp)-1] == '/')
407                err = stat(tmp, &s);
408            else
409                err = lstat(tmp, &s);
410
411            if (err < 0) {
412                perror(tmp);
413                closedir(d);
414                return -1;
415            }
416
417            if (S_ISDIR(s.st_mode)) {
418                strlist_append_dup(&subdirs, tmp);
419            }
420        }
421        strlist_sort(&subdirs);
422        STRLIST_FOREACH(&subdirs, path, {
423            printf("\n%s:\n", path);
424            listdir(path, flags);
425        });
426        strlist_done(&subdirs);
427    }
428
429    closedir(d);
430    return 0;
431}
432
433static int listpath(const char *name, int flags)
434{
435    struct stat s;
436    int err;
437
438    /*
439     * If the name ends in a '/', use stat() so we treat it like a
440     * directory even if it's a symlink.
441     */
442    if (name[strlen(name)-1] == '/')
443        err = stat(name, &s);
444    else
445        err = lstat(name, &s);
446
447    if (err < 0) {
448        perror(name);
449        return -1;
450    }
451
452    if ((flags & LIST_DIRECTORIES) == 0 && S_ISDIR(s.st_mode)) {
453        if (flags & LIST_RECURSIVE)
454            printf("\n%s:\n", name);
455        return listdir(name, flags);
456    } else {
457        /* yeah this calls stat() again*/
458        return listfile(NULL, name, flags);
459    }
460}
461
462int ls_main(int argc, char **argv)
463{
464    int flags = 0;
465    int listed = 0;
466
467    if(argc > 1) {
468        int i;
469        int err = 0;
470        strlist_t  files = STRLIST_INITIALIZER;
471
472        for (i = 1; i < argc; i++) {
473            if (argv[i][0] == '-') {
474                /* an option ? */
475                const char *arg = argv[i]+1;
476                while (arg[0]) {
477                    switch (arg[0]) {
478                    case 'l': flags |= LIST_LONG; break;
479                    case 's': flags |= LIST_SIZE; break;
480                    case 'R': flags |= LIST_RECURSIVE; break;
481                    case 'd': flags |= LIST_DIRECTORIES; break;
482                    case 'a': flags |= LIST_ALL; break;
483                    default:
484                        fprintf(stderr, "%s: Unknown option '-%c'. Aborting.\n", "ls", arg[0]);
485                        exit(1);
486                    }
487                    arg++;
488                }
489            } else {
490                /* not an option ? */
491                strlist_append_dup(&files, argv[i]);
492            }
493        }
494
495        if (files.count > 0) {
496            STRLIST_FOREACH(&files, path, {
497                if (listpath(path, flags) != 0) {
498                    err = EXIT_FAILURE;
499                }
500            });
501            strlist_done(&files);
502            return err;
503        }
504    }
505
506    // list working directory if no files or directories were specified
507    return listpath(".", flags);
508}
509