Merge git://repo.or.cz/git-gui
[git] / help.c
1 /*
2  * builtin-help.c
3  *
4  * Builtin help-related commands (help, usage, version)
5  */
6 #include "cache.h"
7 #include "builtin.h"
8 #include "exec_cmd.h"
9 #include "common-cmds.h"
10 #include "parse-options.h"
11
12 enum help_format {
13         HELP_FORMAT_MAN,
14         HELP_FORMAT_INFO,
15         HELP_FORMAT_WEB,
16 };
17
18 static int show_all = 0;
19 static enum help_format help_format = HELP_FORMAT_MAN;
20 static struct option builtin_help_options[] = {
21         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
22         OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
23         OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
24                         HELP_FORMAT_WEB),
25         OPT_SET_INT('i', "info", &help_format, "show info page",
26                         HELP_FORMAT_INFO),
27 };
28
29 static const char * const builtin_help_usage[] = {
30         "git-help [--all] [--man|--web|--info] [command]",
31         NULL
32 };
33
34 static enum help_format parse_help_format(const char *format)
35 {
36         if (!strcmp(format, "man"))
37                 return HELP_FORMAT_MAN;
38         if (!strcmp(format, "info"))
39                 return HELP_FORMAT_INFO;
40         if (!strcmp(format, "web") || !strcmp(format, "html"))
41                 return HELP_FORMAT_WEB;
42         die("unrecognized help format '%s'", format);
43 }
44
45 static int git_help_config(const char *var, const char *value)
46 {
47         if (!strcmp(var, "help.format")) {
48                 if (!value)
49                         return config_error_nonbool(var);
50                 help_format = parse_help_format(value);
51                 return 0;
52         }
53         return git_default_config(var, value);
54 }
55
56 /* most GUI terminals set COLUMNS (although some don't export it) */
57 static int term_columns(void)
58 {
59         char *col_string = getenv("COLUMNS");
60         int n_cols;
61
62         if (col_string && (n_cols = atoi(col_string)) > 0)
63                 return n_cols;
64
65 #ifdef TIOCGWINSZ
66         {
67                 struct winsize ws;
68                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
69                         if (ws.ws_col)
70                                 return ws.ws_col;
71                 }
72         }
73 #endif
74
75         return 80;
76 }
77
78 static inline void mput_char(char c, unsigned int num)
79 {
80         while(num--)
81                 putchar(c);
82 }
83
84 static struct cmdnames {
85         int alloc;
86         int cnt;
87         struct cmdname {
88                 size_t len;
89                 char name[1];
90         } **names;
91 } main_cmds, other_cmds;
92
93 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
94 {
95         struct cmdname *ent = xmalloc(sizeof(*ent) + len);
96
97         ent->len = len;
98         memcpy(ent->name, name, len);
99         ent->name[len] = 0;
100
101         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
102         cmds->names[cmds->cnt++] = ent;
103 }
104
105 static int cmdname_compare(const void *a_, const void *b_)
106 {
107         struct cmdname *a = *(struct cmdname **)a_;
108         struct cmdname *b = *(struct cmdname **)b_;
109         return strcmp(a->name, b->name);
110 }
111
112 static void uniq(struct cmdnames *cmds)
113 {
114         int i, j;
115
116         if (!cmds->cnt)
117                 return;
118
119         for (i = j = 1; i < cmds->cnt; i++)
120                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
121                         cmds->names[j++] = cmds->names[i];
122
123         cmds->cnt = j;
124 }
125
126 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
127 {
128         int ci, cj, ei;
129         int cmp;
130
131         ci = cj = ei = 0;
132         while (ci < cmds->cnt && ei < excludes->cnt) {
133                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
134                 if (cmp < 0)
135                         cmds->names[cj++] = cmds->names[ci++];
136                 else if (cmp == 0)
137                         ci++, ei++;
138                 else if (cmp > 0)
139                         ei++;
140         }
141
142         while (ci < cmds->cnt)
143                 cmds->names[cj++] = cmds->names[ci++];
144
145         cmds->cnt = cj;
146 }
147
148 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
149 {
150         int cols = 1, rows;
151         int space = longest + 1; /* min 1 SP between words */
152         int max_cols = term_columns() - 1; /* don't print *on* the edge */
153         int i, j;
154
155         if (space < max_cols)
156                 cols = max_cols / space;
157         rows = (cmds->cnt + cols - 1) / cols;
158
159         for (i = 0; i < rows; i++) {
160                 printf("  ");
161
162                 for (j = 0; j < cols; j++) {
163                         int n = j * rows + i;
164                         int size = space;
165                         if (n >= cmds->cnt)
166                                 break;
167                         if (j == cols-1 || n + rows >= cmds->cnt)
168                                 size = 1;
169                         printf("%-*s", size, cmds->names[n]->name);
170                 }
171                 putchar('\n');
172         }
173 }
174
175 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
176                                          const char *path)
177 {
178         unsigned int longest = 0;
179         const char *prefix = "git-";
180         int prefix_len = strlen(prefix);
181         DIR *dir = opendir(path);
182         struct dirent *de;
183
184         if (!dir || chdir(path))
185                 return 0;
186
187         while ((de = readdir(dir)) != NULL) {
188                 struct stat st;
189                 int entlen;
190
191                 if (prefixcmp(de->d_name, prefix))
192                         continue;
193
194                 if (stat(de->d_name, &st) || /* stat, not lstat */
195                     !S_ISREG(st.st_mode) ||
196                     !(st.st_mode & S_IXUSR))
197                         continue;
198
199                 entlen = strlen(de->d_name) - prefix_len;
200                 if (has_extension(de->d_name, ".exe"))
201                         entlen -= 4;
202
203                 if (longest < entlen)
204                         longest = entlen;
205
206                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
207         }
208         closedir(dir);
209
210         return longest;
211 }
212
213 static unsigned int load_command_list(void)
214 {
215         unsigned int longest = 0;
216         unsigned int len;
217         const char *env_path = getenv("PATH");
218         char *paths, *path, *colon;
219         const char *exec_path = git_exec_path();
220
221         if (exec_path)
222                 longest = list_commands_in_dir(&main_cmds, exec_path);
223
224         if (!env_path) {
225                 fprintf(stderr, "PATH not set\n");
226                 exit(1);
227         }
228
229         path = paths = xstrdup(env_path);
230         while (1) {
231                 if ((colon = strchr(path, ':')))
232                         *colon = 0;
233
234                 len = list_commands_in_dir(&other_cmds, path);
235                 if (len > longest)
236                         longest = len;
237
238                 if (!colon)
239                         break;
240                 path = colon + 1;
241         }
242         free(paths);
243
244         qsort(main_cmds.names, main_cmds.cnt,
245               sizeof(*main_cmds.names), cmdname_compare);
246         uniq(&main_cmds);
247
248         qsort(other_cmds.names, other_cmds.cnt,
249               sizeof(*other_cmds.names), cmdname_compare);
250         uniq(&other_cmds);
251         exclude_cmds(&other_cmds, &main_cmds);
252
253         return longest;
254 }
255
256 static void list_commands(void)
257 {
258         unsigned int longest = load_command_list();
259         const char *exec_path = git_exec_path();
260
261         if (main_cmds.cnt) {
262                 printf("available git commands in '%s'\n", exec_path);
263                 printf("----------------------------");
264                 mput_char('-', strlen(exec_path));
265                 putchar('\n');
266                 pretty_print_string_list(&main_cmds, longest);
267                 putchar('\n');
268         }
269
270         if (other_cmds.cnt) {
271                 printf("git commands available from elsewhere on your $PATH\n");
272                 printf("---------------------------------------------------\n");
273                 pretty_print_string_list(&other_cmds, longest);
274                 putchar('\n');
275         }
276 }
277
278 void list_common_cmds_help(void)
279 {
280         int i, longest = 0;
281
282         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
283                 if (longest < strlen(common_cmds[i].name))
284                         longest = strlen(common_cmds[i].name);
285         }
286
287         puts("The most commonly used git commands are:");
288         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
289                 printf("   %s   ", common_cmds[i].name);
290                 mput_char(' ', longest - strlen(common_cmds[i].name));
291                 puts(common_cmds[i].help);
292         }
293 }
294
295 static int is_in_cmdlist(struct cmdnames *c, const char *s)
296 {
297         int i;
298         for (i = 0; i < c->cnt; i++)
299                 if (!strcmp(s, c->names[i]->name))
300                         return 1;
301         return 0;
302 }
303
304 static int is_git_command(const char *s)
305 {
306         load_command_list();
307         return is_in_cmdlist(&main_cmds, s) ||
308                 is_in_cmdlist(&other_cmds, s);
309 }
310
311 static const char *cmd_to_page(const char *git_cmd)
312 {
313         if (!git_cmd)
314                 return "git";
315         else if (!prefixcmp(git_cmd, "git"))
316                 return git_cmd;
317         else {
318                 int page_len = strlen(git_cmd) + 4;
319                 char *p = xmalloc(page_len + 1);
320                 strcpy(p, "git-");
321                 strcpy(p + 4, git_cmd);
322                 p[page_len] = 0;
323                 return p;
324         }
325 }
326
327 static void setup_man_path(void)
328 {
329         struct strbuf new_path;
330         const char *old_path = getenv("MANPATH");
331
332         strbuf_init(&new_path, 0);
333
334         /* We should always put ':' after our path. If there is no
335          * old_path, the ':' at the end will let 'man' to try
336          * system-wide paths after ours to find the manual page. If
337          * there is old_path, we need ':' as delimiter. */
338         strbuf_addstr(&new_path, GIT_MAN_PATH);
339         strbuf_addch(&new_path, ':');
340         if (old_path)
341                 strbuf_addstr(&new_path, old_path);
342
343         setenv("MANPATH", new_path.buf, 1);
344
345         strbuf_release(&new_path);
346 }
347
348 static void show_man_page(const char *git_cmd)
349 {
350         const char *page = cmd_to_page(git_cmd);
351         setup_man_path();
352         execlp("man", "man", page, NULL);
353 }
354
355 static void show_info_page(const char *git_cmd)
356 {
357         const char *page = cmd_to_page(git_cmd);
358         setenv("INFOPATH", GIT_INFO_PATH, 1);
359         execlp("info", "info", "gitman", page, NULL);
360 }
361
362 static void get_html_page_path(struct strbuf *page_path, const char *page)
363 {
364         struct stat st;
365
366         /* Check that we have a git documentation directory. */
367         if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
368                 die("'%s': not a documentation directory.", GIT_HTML_PATH);
369
370         strbuf_init(page_path, 0);
371         strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
372 }
373
374 static void show_html_page(const char *git_cmd)
375 {
376         const char *page = cmd_to_page(git_cmd);
377         struct strbuf page_path; /* it leaks but we exec bellow */
378
379         get_html_page_path(&page_path, page);
380
381         execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
382 }
383
384 void help_unknown_cmd(const char *cmd)
385 {
386         fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
387         exit(1);
388 }
389
390 int cmd_version(int argc, const char **argv, const char *prefix)
391 {
392         printf("git version %s\n", git_version_string);
393         return 0;
394 }
395
396 int cmd_help(int argc, const char **argv, const char *prefix)
397 {
398         int nongit;
399         const char *alias;
400
401         setup_git_directory_gently(&nongit);
402         git_config(git_help_config);
403
404         argc = parse_options(argc, argv, builtin_help_options,
405                         builtin_help_usage, 0);
406
407         if (show_all) {
408                 printf("usage: %s\n\n", git_usage_string);
409                 list_commands();
410                 return 0;
411         }
412
413         if (!argv[0]) {
414                 printf("usage: %s\n\n", git_usage_string);
415                 list_common_cmds_help();
416                 return 0;
417         }
418
419         alias = alias_lookup(argv[0]);
420         if (alias && !is_git_command(argv[0])) {
421                 printf("`git %s' is aliased to `%s'\n", argv[0], alias);
422                 return 0;
423         }
424
425         switch (help_format) {
426         case HELP_FORMAT_MAN:
427                 show_man_page(argv[0]);
428                 break;
429         case HELP_FORMAT_INFO:
430                 show_info_page(argv[0]);
431                 break;
432         case HELP_FORMAT_WEB:
433                 show_html_page(argv[0]);
434                 break;
435         }
436
437         return 0;
438 }