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 #include "run-command.h"
  12
  13 static const char *man_viewer;
  14
  15 enum help_format {
  16         HELP_FORMAT_MAN,
  17         HELP_FORMAT_INFO,
  18         HELP_FORMAT_WEB,
  19 };
  20
  21 static int show_all = 0;
  22 static enum help_format help_format = HELP_FORMAT_MAN;
  23 static struct option builtin_help_options[] = {
  24         OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  25         OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  26         OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  27                         HELP_FORMAT_WEB),
  28         OPT_SET_INT('i', "info", &help_format, "show info page",
  29                         HELP_FORMAT_INFO),
  30 };
  31
  32 static const char * const builtin_help_usage[] = {
  33         "git-help [--all] [--man|--web|--info] [command]",
  34         NULL
  35 };
  36
  37 static enum help_format parse_help_format(const char *format)
  38 {
  39         if (!strcmp(format, "man"))
  40                 return HELP_FORMAT_MAN;
  41         if (!strcmp(format, "info"))
  42                 return HELP_FORMAT_INFO;
  43         if (!strcmp(format, "web") || !strcmp(format, "html"))
  44                 return HELP_FORMAT_WEB;
  45         die("unrecognized help format '%s'", format);
  46 }
  47
  48 static int git_help_config(const char *var, const char *value)
  49 {
  50         if (!strcmp(var, "help.format")) {
  51                 if (!value)
  52                         return config_error_nonbool(var);
  53                 help_format = parse_help_format(value);
  54                 return 0;
  55         }
  56         if (!strcmp(var, "man.viewer"))
  57                 return git_config_string(&man_viewer, var, value);
  58         return git_default_config(var, value);
  59 }
  60
  61 /* most GUI terminals set COLUMNS (although some don't export it) */
  62 static int term_columns(void)
  63 {
  64         char *col_string = getenv("COLUMNS");
  65         int n_cols;
  66
  67         if (col_string && (n_cols = atoi(col_string)) > 0)
  68                 return n_cols;
  69
  70 #ifdef TIOCGWINSZ
  71         {
  72                 struct winsize ws;
  73                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
  74                         if (ws.ws_col)
  75                                 return ws.ws_col;
  76                 }
  77         }
  78 #endif
  79
  80         return 80;
  81 }
  82
  83 static inline void mput_char(char c, unsigned int num)
  84 {
  85         while(num--)
  86                 putchar(c);
  87 }
  88
  89 static struct cmdnames {
  90         int alloc;
  91         int cnt;
  92         struct cmdname {
  93                 size_t len;
  94                 char name[1];
  95         } **names;
  96 } main_cmds, other_cmds;
  97
  98 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  99 {
 100         struct cmdname *ent = xmalloc(sizeof(*ent) + len);
 101
 102         ent->len = len;
 103         memcpy(ent->name, name, len);
 104         ent->name[len] = 0;
 105
 106         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 107         cmds->names[cmds->cnt++] = ent;
 108 }
 109
 110 static int cmdname_compare(const void *a_, const void *b_)
 111 {
 112         struct cmdname *a = *(struct cmdname **)a_;
 113         struct cmdname *b = *(struct cmdname **)b_;
 114         return strcmp(a->name, b->name);
 115 }
 116
 117 static void uniq(struct cmdnames *cmds)
 118 {
 119         int i, j;
 120
 121         if (!cmds->cnt)
 122                 return;
 123
 124         for (i = j = 1; i < cmds->cnt; i++)
 125                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 126                         cmds->names[j++] = cmds->names[i];
 127
 128         cmds->cnt = j;
 129 }
 130
 131 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 132 {
 133         int ci, cj, ei;
 134         int cmp;
 135
 136         ci = cj = ei = 0;
 137         while (ci < cmds->cnt && ei < excludes->cnt) {
 138                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 139                 if (cmp < 0)
 140                         cmds->names[cj++] = cmds->names[ci++];
 141                 else if (cmp == 0)
 142                         ci++, ei++;
 143                 else if (cmp > 0)
 144                         ei++;
 145         }
 146
 147         while (ci < cmds->cnt)
 148                 cmds->names[cj++] = cmds->names[ci++];
 149
 150         cmds->cnt = cj;
 151 }
 152
 153 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 154 {
 155         int cols = 1, rows;
 156         int space = longest + 1; /* min 1 SP between words */
 157         int max_cols = term_columns() - 1; /* don't print *on* the edge */
 158         int i, j;
 159
 160         if (space < max_cols)
 161                 cols = max_cols / space;
 162         rows = (cmds->cnt + cols - 1) / cols;
 163
 164         for (i = 0; i < rows; i++) {
 165                 printf("  ");
 166
 167                 for (j = 0; j < cols; j++) {
 168                         int n = j * rows + i;
 169                         int size = space;
 170                         if (n >= cmds->cnt)
 171                                 break;
 172                         if (j == cols-1 || n + rows >= cmds->cnt)
 173                                 size = 1;
 174                         printf("%-*s", size, cmds->names[n]->name);
 175                 }
 176                 putchar('\n');
 177         }
 178 }
 179
 180 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 181                                          const char *path)
 182 {
 183         unsigned int longest = 0;
 184         const char *prefix = "git-";
 185         int prefix_len = strlen(prefix);
 186         DIR *dir = opendir(path);
 187         struct dirent *de;
 188
 189         if (!dir || chdir(path))
 190                 return 0;
 191
 192         while ((de = readdir(dir)) != NULL) {
 193                 struct stat st;
 194                 int entlen;
 195
 196                 if (prefixcmp(de->d_name, prefix))
 197                         continue;
 198
 199                 if (stat(de->d_name, &st) || /* stat, not lstat */
 200                     !S_ISREG(st.st_mode) ||
 201                     !(st.st_mode & S_IXUSR))
 202                         continue;
 203
 204                 entlen = strlen(de->d_name) - prefix_len;
 205                 if (has_extension(de->d_name, ".exe"))
 206                         entlen -= 4;
 207
 208                 if (longest < entlen)
 209                         longest = entlen;
 210
 211                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
 212         }
 213         closedir(dir);
 214
 215         return longest;
 216 }
 217
 218 static unsigned int load_command_list(void)
 219 {
 220         unsigned int longest = 0;
 221         unsigned int len;
 222         const char *env_path = getenv("PATH");
 223         char *paths, *path, *colon;
 224         const char *exec_path = git_exec_path();
 225
 226         if (exec_path)
 227                 longest = list_commands_in_dir(&main_cmds, exec_path);
 228
 229         if (!env_path) {
 230                 fprintf(stderr, "PATH not set\n");
 231                 exit(1);
 232         }
 233
 234         path = paths = xstrdup(env_path);
 235         while (1) {
 236                 if ((colon = strchr(path, ':')))
 237                         *colon = 0;
 238
 239                 len = list_commands_in_dir(&other_cmds, path);
 240                 if (len > longest)
 241                         longest = len;
 242
 243                 if (!colon)
 244                         break;
 245                 path = colon + 1;
 246         }
 247         free(paths);
 248
 249         qsort(main_cmds.names, main_cmds.cnt,
 250               sizeof(*main_cmds.names), cmdname_compare);
 251         uniq(&main_cmds);
 252
 253         qsort(other_cmds.names, other_cmds.cnt,
 254               sizeof(*other_cmds.names), cmdname_compare);
 255         uniq(&other_cmds);
 256         exclude_cmds(&other_cmds, &main_cmds);
 257
 258         return longest;
 259 }
 260
 261 static void list_commands(void)
 262 {
 263         unsigned int longest = load_command_list();
 264         const char *exec_path = git_exec_path();
 265
 266         if (main_cmds.cnt) {
 267                 printf("available git commands in '%s'\n", exec_path);
 268                 printf("----------------------------");
 269                 mput_char('-', strlen(exec_path));
 270                 putchar('\n');
 271                 pretty_print_string_list(&main_cmds, longest);
 272                 putchar('\n');
 273         }
 274
 275         if (other_cmds.cnt) {
 276                 printf("git commands available from elsewhere on your $PATH\n");
 277                 printf("---------------------------------------------------\n");
 278                 pretty_print_string_list(&other_cmds, longest);
 279                 putchar('\n');
 280         }
 281 }
 282
 283 void list_common_cmds_help(void)
 284 {
 285         int i, longest = 0;
 286
 287         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 288                 if (longest < strlen(common_cmds[i].name))
 289                         longest = strlen(common_cmds[i].name);
 290         }
 291
 292         puts("The most commonly used git commands are:");
 293         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 294                 printf("   %s   ", common_cmds[i].name);
 295                 mput_char(' ', longest - strlen(common_cmds[i].name));
 296                 puts(common_cmds[i].help);
 297         }
 298 }
 299
 300 static int is_in_cmdlist(struct cmdnames *c, const char *s)
 301 {
 302         int i;
 303         for (i = 0; i < c->cnt; i++)
 304                 if (!strcmp(s, c->names[i]->name))
 305                         return 1;
 306         return 0;
 307 }
 308
 309 static int is_git_command(const char *s)
 310 {
 311         load_command_list();
 312         return is_in_cmdlist(&main_cmds, s) ||
 313                 is_in_cmdlist(&other_cmds, s);
 314 }
 315
 316 static const char *cmd_to_page(const char *git_cmd)
 317 {
 318         if (!git_cmd)
 319                 return "git";
 320         else if (!prefixcmp(git_cmd, "git"))
 321                 return git_cmd;
 322         else {
 323                 int page_len = strlen(git_cmd) + 4;
 324                 char *p = xmalloc(page_len + 1);
 325                 strcpy(p, "git-");
 326                 strcpy(p + 4, git_cmd);
 327                 p[page_len] = 0;
 328                 return p;
 329         }
 330 }
 331
 332 static void setup_man_path(void)
 333 {
 334         struct strbuf new_path;
 335         const char *old_path = getenv("MANPATH");
 336
 337         strbuf_init(&new_path, 0);
 338
 339         /* We should always put ':' after our path. If there is no
 340          * old_path, the ':' at the end will let 'man' to try
 341          * system-wide paths after ours to find the manual page. If
 342          * there is old_path, we need ':' as delimiter. */
 343         strbuf_addstr(&new_path, GIT_MAN_PATH);
 344         strbuf_addch(&new_path, ':');
 345         if (old_path)
 346                 strbuf_addstr(&new_path, old_path);
 347
 348         setenv("MANPATH", new_path.buf, 1);
 349
 350         strbuf_release(&new_path);
 351 }
 352
 353 static int check_emacsclient_version(void)
 354 {
 355         struct strbuf buffer = STRBUF_INIT;
 356         struct child_process ec_process;
 357         const char *argv_ec[] = { "emacsclient", "--version", NULL };
 358         int version;
 359
 360         /* emacsclient prints its version number on stderr */
 361         memset(&ec_process, 0, sizeof(ec_process));
 362         ec_process.argv = argv_ec;
 363         ec_process.err = -1;
 364         ec_process.stdout_to_stderr = 1;
 365         if (start_command(&ec_process)) {
 366                 fprintf(stderr, "Failed to start emacsclient.\n");
 367                 return -1;
 368         }
 369         strbuf_read(&buffer, ec_process.err, 20);
 370         close(ec_process.err);
 371
 372         /*
 373          * Don't bother checking return value, because "emacsclient --version"
 374          * seems to always exits with code 1.
 375          */
 376         finish_command(&ec_process);
 377
 378         if (prefixcmp(buffer.buf, "emacsclient")) {
 379                 fprintf(stderr, "Failed to parse emacsclient version.\n");
 380                 strbuf_release(&buffer);
 381                 return -1;
 382         }
 383
 384         strbuf_remove(&buffer, 0, strlen("emacsclient"));
 385         version = atoi(buffer.buf);
 386
 387         if (version < 22) {
 388                 fprintf(stderr,
 389                         "emacsclient version '%d' too old (< 22).\n",
 390                         version);
 391                 strbuf_release(&buffer);
 392                 return -1;
 393         }
 394
 395         strbuf_release(&buffer);
 396         return 0;
 397 }
 398
 399 static void exec_woman_emacs(const char *page)
 400 {
 401         if (!check_emacsclient_version()) {
 402                 /* This works only with emacsclient version >= 22. */
 403                 struct strbuf man_page = STRBUF_INIT;
 404                 strbuf_addf(&man_page, "(woman \"%s\")", page);
 405                 execlp("emacsclient", "emacsclient", "-e", man_page.buf, NULL);
 406         } else
 407                 execlp("man", "man", page, NULL);
 408 }
 409
 410 static void exec_man_konqueror(const char *page)
 411 {
 412         const char *display = getenv("DISPLAY");
 413         if (display && *display) {
 414                 struct strbuf man_page = STRBUF_INIT;
 415                 strbuf_addf(&man_page, "man:%s(1)", page);
 416                 execlp("kfmclient", "kfmclient", "newTab", man_page.buf, NULL);
 417         } else
 418                 execlp("man", "man", page, NULL);
 419 }
 420
 421 static void show_man_page(const char *git_cmd)
 422 {
 423         const char *page = cmd_to_page(git_cmd);
 424         setup_man_path();
 425         if (!man_viewer || !strcmp(man_viewer, "man"))
 426                 execlp("man", "man", page, NULL);
 427         if (!strcmp(man_viewer, "woman"))
 428                 exec_woman_emacs(page);
 429         if (!strcmp(man_viewer, "konqueror"))
 430                 exec_man_konqueror(page);
 431         die("'%s': unsupported man viewer.", man_viewer);
 432 }
 433
 434 static void show_info_page(const char *git_cmd)
 435 {
 436         const char *page = cmd_to_page(git_cmd);
 437         setenv("INFOPATH", GIT_INFO_PATH, 1);
 438         execlp("info", "info", "gitman", page, NULL);
 439 }
 440
 441 static void get_html_page_path(struct strbuf *page_path, const char *page)
 442 {
 443         struct stat st;
 444
 445         /* Check that we have a git documentation directory. */
 446         if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
 447                 die("'%s': not a documentation directory.", GIT_HTML_PATH);
 448
 449         strbuf_init(page_path, 0);
 450         strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
 451 }
 452
 453 static void show_html_page(const char *git_cmd)
 454 {
 455         const char *page = cmd_to_page(git_cmd);
 456         struct strbuf page_path; /* it leaks but we exec bellow */
 457
 458         get_html_page_path(&page_path, page);
 459
 460         execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
 461 }
 462
 463 void help_unknown_cmd(const char *cmd)
 464 {
 465         fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 466         exit(1);
 467 }
 468
 469 int cmd_version(int argc, const char **argv, const char *prefix)
 470 {
 471         printf("git version %s\n", git_version_string);
 472         return 0;
 473 }
 474
 475 int cmd_help(int argc, const char **argv, const char *prefix)
 476 {
 477         int nongit;
 478         const char *alias;
 479
 480         setup_git_directory_gently(&nongit);
 481         git_config(git_help_config);
 482
 483         argc = parse_options(argc, argv, builtin_help_options,
 484                         builtin_help_usage, 0);
 485
 486         if (show_all) {
 487                 printf("usage: %s\n\n", git_usage_string);
 488                 list_commands();
 489                 return 0;
 490         }
 491
 492         if (!argv[0]) {
 493                 printf("usage: %s\n\n", git_usage_string);
 494                 list_common_cmds_help();
 495                 return 0;
 496         }
 497
 498         alias = alias_lookup(argv[0]);
 499         if (alias && !is_git_command(argv[0])) {
 500                 printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 501                 return 0;
 502         }
 503
 504         switch (help_format) {
 505         case HELP_FORMAT_MAN:
 506                 show_man_page(argv[0]);
 507                 break;
 508         case HELP_FORMAT_INFO:
 509                 show_info_page(argv[0]);
 510                 break;
 511         case HELP_FORMAT_WEB:
 512                 show_html_page(argv[0]);
 513                 break;
 514         }
 515
 516         return 0;
 517 }