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DEFINITIONS
This source file includes following definitions.
- option
- basename
- isdir
- printheader
- print
- listdir
- recursedir
- listitem
- main
1 /*
2 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
3 * The President and Fellows of Harvard College.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #include <stdio.h>
33 #include <unistd.h>
34 #include <string.h>
35 #include <errno.h>
36 #include <err.h>
37
38 /*
39 * ls - list files.
40 * Usage: ls [-adlRs] [files]
41 * -a Show files whose names begin with a dot.
42 * -d Don't list contents of directories specified on the command line.
43 * -l Long format listing.
44 * -R Recurse into subdirectories found.
45 * -s (with -l) Show block counts.
46 */
47
48 /* Flags for which options we're using. */
49 static int aopt=0;
50 static int dopt=0;
51 static int lopt=0;
52 static int Ropt=0;
53 static int sopt=0;
54
55 /* Process an option character. */
56 static
57 void
58 option(int ch)
59 {
60 switch (ch) {
61 case 'a': aopt=1; break;
62 case 'd': dopt=1; break;
63 case 'l': lopt=1; break;
64 case 'R': Ropt=1; break;
65 case 's': sopt=1; break;
66 default:
67 errx(1, "Unknown option -%c", ch);
68 }
69 }
70
71 /*
72 * Utility function to find the non-directory part of a pathname.
73 */
74 static
75 const char *
76 basename(const char *path)
77 {
78 const char *s;
79
80 s = strrchr(path, '/');
81 if (s) {
82 return s+1;
83 }
84 return path;
85 }
86
87 /*
88 * Utility function to check if a name refers to a directory.
89 */
90 static
91 int
92 isdir(const char *path)
93 {
94 struct stat buf;
95 int fd;
96
97 /* Assume stat() may not be implemented; use fstat */
98 fd = open(path, O_RDONLY);
99 if (fd<0) {
100 err(1, "%s", path);
101 }
102 if (fstat(fd, &buf)<0) {
103 err(1, "%s: fstat", path);
104 }
105 close(fd);
106
107 return S_ISDIR(buf.st_mode);
108 }
109
110 /*
111 * When listing one of several subdirectories, show the name of the
112 * directory.
113 */
114 static
115 void
116 printheader(const char *file)
117 {
118 /* No blank line before the first header */
119 static int first=1;
120 if (first) {
121 first = 0;
122 }
123 else {
124 printf("\n");
125 }
126 printf("%s:\n", file);
127 }
128
129 /*
130 * Show a single file.
131 * We don't do the neat multicolumn listing that Unix ls does.
132 */
133 static
134 void
135 print(const char *path)
136 {
137 struct stat statbuf;
138 const char *file;
139 int typech;
140
141 if (lopt || sopt) {
142 int fd;
143
144 fd = open(path, O_RDONLY);
145 if (fd<0) {
146 err(1, "%s", path);
147 }
148 if (fstat(fd, &statbuf)<0) {
149 err(1, "%s: fstat", path);
150 }
151 close(fd);
152 }
153
154 file = basename(path);
155
156 if (sopt) {
157 printf("%3d ", statbuf.st_blocks);
158 }
159
160 if (lopt) {
161 if (S_ISREG(statbuf.st_mode)) {
162 typech = '-';
163 }
164 else if (S_ISDIR(statbuf.st_mode)) {
165 typech = 'd';
166 }
167 else if (S_ISLNK(statbuf.st_mode)) {
168 typech = 'l';
169 }
170 else if (S_ISCHR(statbuf.st_mode)) {
171 typech = 'c';
172 }
173 else if (S_ISBLK(statbuf.st_mode)) {
174 typech = 'b';
175 }
176 else {
177 typech = '?';
178 }
179
180 printf("%crwx------ %2d root %-8llu",
181 typech,
182 statbuf.st_nlink,
183 statbuf.st_size);
184 }
185 printf("%s\n", file);
186 }
187
188 /*
189 * List a directory.
190 */
191 static
192 void
193 listdir(const char *path, int showheader)
194 {
195 int fd;
196 char buf[1024];
197 char newpath[1024];
198 int len;
199
200 if (showheader) {
201 printheader(path);
202 }
203
204 /*
205 * Open it.
206 */
207 fd = open(path, O_RDONLY);
208 if (fd<0) {
209 err(1, "%s", path);
210 }
211
212 /*
213 * List the directory.
214 */
215 while ((len = getdirentry(fd, buf, sizeof(buf)-1)) > 0) {
216 buf[len] = 0;
217
218 /* Assemble the full name of the new item */
219 snprintf(newpath, sizeof(newpath), "%s/%s", path, buf);
220
221 if (aopt || buf[0]!='.') {
222 /* Print it */
223 print(newpath);
224 }
225 }
226 if (len<0) {
227 err(1, "%s: getdirentry", path);
228 }
229
230 /* Done */
231 close(fd);
232 }
233
234 static
235 void
236 recursedir(const char *path)
237 {
238 int fd;
239 char buf[1024];
240 char newpath[1024];
241 int len;
242
243 /*
244 * Open it.
245 */
246 fd = open(path, O_RDONLY);
247 if (fd<0) {
248 err(1, "%s", path);
249 }
250
251 /*
252 * List the directory.
253 */
254 while ((len = getdirentry(fd, buf, sizeof(buf)-1)) > 0) {
255 buf[len] = 0;
256
257 /* Assemble the full name of the new item */
258 snprintf(newpath, sizeof(newpath), "%s/%s", path, buf);
259
260 if (!aopt && buf[0]=='.') {
261 /* skip this one */
262 continue;
263 }
264
265 if (!strcmp(buf, ".") || !strcmp(buf, "..")) {
266 /* always skip these */
267 continue;
268 }
269
270 if (!isdir(newpath)) {
271 continue;
272 }
273
274 listdir(newpath, 1 /*showheader*/);
275 if (Ropt) {
276 recursedir(newpath);
277 }
278 }
279 if (len<0) {
280 err(1, "%s", path);
281 }
282
283 close(fd);
284 }
285
286 static
287 void
288 listitem(const char *path, int showheader)
289 {
290 if (!dopt && isdir(path)) {
291 listdir(path, showheader || Ropt);
292 if (Ropt) {
293 recursedir(path);
294 }
295 }
296 else {
297 print(path);
298 }
299 }
300
301 int
302 main(int argc, char *argv[])
303 {
304 int i,j, items=0;
305
306 /*
307 * Go through the arguments and count how many non-option args.
308 */
309 for (i=1; i<argc; i++) {
310 if (argv[i][0]!='-') {
311 items++;
312 }
313 }
314
315 /*
316 * Now go through the options for real, processing them.
317 */
318 for (i=1; i<argc; i++) {
319 if (argv[i][0]=='-') {
320 /*
321 * This word is an option.
322 * Process all the option characters in it.
323 */
324 for (j=1; argv[i][j]; j++) {
325 option(argv[i][j]);
326 }
327 }
328 else {
329 /*
330 * This word isn't an option; list it.
331 */
332 listitem(argv[i], items>1);
333 }
334 }
335
336 /*
337 * If no filenames were specified to list, list the current
338 * directory.
339 */
340 if (items==0) {
341 listitem(".", 0);
342 }
343
344 return 0;
345 }