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 }