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