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