Documentation: user-manual: add information about "git help" at the beginning
[git] / diff-no-index.c
1 /*
2  * "diff --no-index" support
3  * Copyright (c) 2007 by Johannes Schindelin
4  * Copyright (c) 2008 by Junio C Hamano
5  */
6
7 #include "cache.h"
8 #include "color.h"
9 #include "commit.h"
10 #include "blob.h"
11 #include "tag.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "revision.h"
15 #include "log-tree.h"
16 #include "builtin.h"
17 #include "string-list.h"
18
19 static int read_directory(const char *path, struct string_list *list)
20 {
21         DIR *dir;
22         struct dirent *e;
23
24         if (!(dir = opendir(path)))
25                 return error("Could not open directory %s", path);
26
27         while ((e = readdir(dir)))
28                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
29                         string_list_insert(e->d_name, list);
30
31         closedir(dir);
32         return 0;
33 }
34
35 static int get_mode(const char *path, int *mode)
36 {
37         struct stat st;
38
39         if (!path || !strcmp(path, "/dev/null"))
40                 *mode = 0;
41         else if (!strcmp(path, "-"))
42                 *mode = create_ce_mode(0666);
43         else if (stat(path, &st))
44                 return error("Could not access '%s'", path);
45         else
46                 *mode = st.st_mode;
47         return 0;
48 }
49
50 static int queue_diff(struct diff_options *o,
51                 const char *name1, const char *name2)
52 {
53         int mode1 = 0, mode2 = 0;
54
55         if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
56                 return -1;
57
58         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
59                 return error("file/directory conflict: %s, %s", name1, name2);
60
61         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
62                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
63                 struct string_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
64                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
65
66                 if (name1 && read_directory(name1, &p1))
67                         return -1;
68                 if (name2 && read_directory(name2, &p2)) {
69                         string_list_clear(&p1, 0);
70                         return -1;
71                 }
72
73                 if (name1) {
74                         len1 = strlen(name1);
75                         if (len1 > 0 && name1[len1 - 1] == '/')
76                                 len1--;
77                         memcpy(buffer1, name1, len1);
78                         buffer1[len1++] = '/';
79                 }
80
81                 if (name2) {
82                         len2 = strlen(name2);
83                         if (len2 > 0 && name2[len2 - 1] == '/')
84                                 len2--;
85                         memcpy(buffer2, name2, len2);
86                         buffer2[len2++] = '/';
87                 }
88
89                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
90                         const char *n1, *n2;
91                         int comp;
92
93                         if (i1 == p1.nr)
94                                 comp = 1;
95                         else if (i2 == p2.nr)
96                                 comp = -1;
97                         else
98                                 comp = strcmp(p1.items[i1].string,
99                                         p2.items[i2].string);
100
101                         if (comp > 0)
102                                 n1 = NULL;
103                         else {
104                                 n1 = buffer1;
105                                 strncpy(buffer1 + len1, p1.items[i1++].string,
106                                                 PATH_MAX - len1);
107                         }
108
109                         if (comp < 0)
110                                 n2 = NULL;
111                         else {
112                                 n2 = buffer2;
113                                 strncpy(buffer2 + len2, p2.items[i2++].string,
114                                                 PATH_MAX - len2);
115                         }
116
117                         ret = queue_diff(o, n1, n2);
118                 }
119                 string_list_clear(&p1, 0);
120                 string_list_clear(&p2, 0);
121
122                 return ret;
123         } else {
124                 struct diff_filespec *d1, *d2;
125
126                 if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
127                         unsigned tmp;
128                         const char *tmp_c;
129                         tmp = mode1; mode1 = mode2; mode2 = tmp;
130                         tmp_c = name1; name1 = name2; name2 = tmp_c;
131                 }
132
133                 if (!name1)
134                         name1 = "/dev/null";
135                 if (!name2)
136                         name2 = "/dev/null";
137                 d1 = alloc_filespec(name1);
138                 d2 = alloc_filespec(name2);
139                 fill_filespec(d1, null_sha1, mode1);
140                 fill_filespec(d2, null_sha1, mode2);
141
142                 diff_queue(&diff_queued_diff, d1, d2);
143                 return 0;
144         }
145 }
146
147 static int path_outside_repo(const char *path)
148 {
149         /*
150          * We have already done setup_git_directory_gently() so we
151          * know we are inside a git work tree already.
152          */
153         const char *work_tree;
154         size_t len;
155
156         if (!is_absolute_path(path))
157                 return 0;
158         work_tree = get_git_work_tree();
159         len = strlen(work_tree);
160         if (strncmp(path, work_tree, len) ||
161             (path[len] != '\0' && path[len] != '/'))
162                 return 1;
163         return 0;
164 }
165
166 void diff_no_index(struct rev_info *revs,
167                    int argc, const char **argv,
168                    int nongit, const char *prefix)
169 {
170         int i;
171         int no_index = 0;
172         unsigned options = 0;
173
174         /* Were we asked to do --no-index explicitly? */
175         for (i = 1; i < argc; i++) {
176                 if (!strcmp(argv[i], "--"))
177                         return;
178                 if (!strcmp(argv[i], "--no-index"))
179                         no_index = 1;
180                 if (argv[i][0] != '-')
181                         break;
182         }
183
184         if (!no_index && !nongit) {
185                 /*
186                  * Inside a git repository, without --no-index.  Only
187                  * when a path outside the repository is given,
188                  * e.g. "git diff /var/tmp/[12]", or "git diff
189                  * Makefile /var/tmp/Makefile", allow it to be used as
190                  * a colourful "diff" replacement.
191                  */
192                 if ((argc != i + 2) ||
193                     (!path_outside_repo(argv[i]) &&
194                      !path_outside_repo(argv[i+1])))
195                         return;
196         }
197         if (argc != i + 2)
198                 die("git diff %s takes two paths",
199                     no_index ? "--no-index" : "[--no-index]");
200
201         /*
202          * If the user asked for our exit code then don't start a
203          * pager or we would end up reporting its exit code instead.
204          */
205         if (!DIFF_OPT_TST(&revs->diffopt, EXIT_WITH_STATUS))
206                 setup_pager();
207
208         diff_setup(&revs->diffopt);
209         if (!revs->diffopt.output_format)
210                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
211         for (i = 1; i < argc - 2; ) {
212                 int j;
213                 if (!strcmp(argv[i], "--no-index"))
214                         i++;
215                 else if (!strcmp(argv[1], "-q"))
216                         options |= DIFF_SILENT_ON_REMOVED;
217                 else {
218                         j = diff_opt_parse(&revs->diffopt, argv + i, argc - i);
219                         if (!j)
220                                 die("invalid diff option/value: %s", argv[i]);
221                         i += j;
222                 }
223         }
224
225         if (prefix) {
226                 int len = strlen(prefix);
227
228                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
229                 for (i = 0; i < 2; i++) {
230                         const char *p = argv[argc - 2 + i];
231                         /*
232                          * stdin should be spelled as '-'; if you have
233                          * path that is '-', spell it as ./-.
234                          */
235                         p = (strcmp(p, "-")
236                              ? xstrdup(prefix_filename(prefix, len, p))
237                              : p);
238                         revs->diffopt.paths[i] = p;
239                 }
240         }
241         else
242                 revs->diffopt.paths = argv + argc - 2;
243         revs->diffopt.nr_paths = 2;
244
245         DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
246         DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
247
248         revs->max_count = -2;
249         if (diff_setup_done(&revs->diffopt) < 0)
250                 die("diff_setup_done failed");
251
252         if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
253                        revs->diffopt.paths[1]))
254                 exit(1);
255         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
256         diffcore_std(&revs->diffopt);
257         diff_flush(&revs->diffopt);
258
259         /*
260          * The return code for --no-index imitates diff(1):
261          * 0 = no changes, 1 = changes, else error
262          */
263         exit(revs->diffopt.found_changes);
264 }