Andrew's git / gitweb.git / help.c
?
help.con commit git-submodule: replace duplicated code with a module_list function (a7b3269)
   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
  13static struct man_viewer_list {
  14        struct man_viewer_list *next;
  15        char name[FLEX_ARRAY];
  16} *man_viewer_list;
  17
  18static struct man_viewer_info_list {
  19        struct man_viewer_info_list *next;
  20        const char *info;
  21        char name[FLEX_ARRAY];
  22} *man_viewer_info_list;
  23
  24enum help_format {
  25        HELP_FORMAT_MAN,
  26        HELP_FORMAT_INFO,
  27        HELP_FORMAT_WEB,
  28};
  29
  30static int show_all = 0;
  31static enum help_format help_format = HELP_FORMAT_MAN;
  32static struct option builtin_help_options[] = {
  33        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  34        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  35        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  36                        HELP_FORMAT_WEB),
  37        OPT_SET_INT('i', "info", &help_format, "show info page",
  38                        HELP_FORMAT_INFO),
  39        OPT_END(),
  40};
  41
  42static const char * const builtin_help_usage[] = {
  43        "git help [--all] [--man|--web|--info] [command]",
  44        NULL
  45};
  46
  47static enum help_format parse_help_format(const char *format)
  48{
  49        if (!strcmp(format, "man"))
  50                return HELP_FORMAT_MAN;
  51        if (!strcmp(format, "info"))
  52                return HELP_FORMAT_INFO;
  53        if (!strcmp(format, "web") || !strcmp(format, "html"))
  54                return HELP_FORMAT_WEB;
  55        die("unrecognized help format '%s'", format);
  56}
  57
  58static const char *get_man_viewer_info(const char *name)
  59{
  60        struct man_viewer_info_list *viewer;
  61
  62        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  63        {
  64                if (!strcasecmp(name, viewer->name))
  65                        return viewer->info;
  66        }
  67        return NULL;
  68}
  69
  70static int check_emacsclient_version(void)
  71{
  72        struct strbuf buffer = STRBUF_INIT;
  73        struct child_process ec_process;
  74        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  75        int version;
  76
  77        /* emacsclient prints its version number on stderr */
  78        memset(&ec_process, 0, sizeof(ec_process));
  79        ec_process.argv = argv_ec;
  80        ec_process.err = -1;
  81        ec_process.stdout_to_stderr = 1;
  82        if (start_command(&ec_process)) {
  83                fprintf(stderr, "Failed to start emacsclient.\n");
  84                return -1;
  85        }
  86        strbuf_read(&buffer, ec_process.err, 20);
  87        close(ec_process.err);
  88
  89        /*
  90         * Don't bother checking return value, because "emacsclient --version"
  91         * seems to always exits with code 1.
  92         */
  93        finish_command(&ec_process);
  94
  95        if (prefixcmp(buffer.buf, "emacsclient")) {
  96                fprintf(stderr, "Failed to parse emacsclient version.\n");
  97                strbuf_release(&buffer);
  98                return -1;
  99        }
 100
 101        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 102        version = atoi(buffer.buf);
 103
 104        if (version < 22) {
 105                fprintf(stderr,
 106                        "emacsclient version '%d' too old (< 22).\n",
 107                        version);
 108                strbuf_release(&buffer);
 109                return -1;
 110        }
 111
 112        strbuf_release(&buffer);
 113        return 0;
 114}
 115
 116static void exec_woman_emacs(const char* path, const char *page)
 117{
 118        if (!check_emacsclient_version()) {
 119                /* This works only with emacsclient version >= 22. */
 120                struct strbuf man_page = STRBUF_INIT;
 121
 122                if (!path)
 123                        path = "emacsclient";
 124                strbuf_addf(&man_page, "(woman \"%s\")", page);
 125                execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 126                warning("failed to exec '%s': %s", path, strerror(errno));
 127        }
 128}
 129
 130static void exec_man_konqueror(const char* path, const char *page)
 131{
 132        const char *display = getenv("DISPLAY");
 133        if (display && *display) {
 134                struct strbuf man_page = STRBUF_INIT;
 135                const char *filename = "kfmclient";
 136
 137                /* It's simpler to launch konqueror using kfmclient. */
 138                if (path) {
 139                        const char *file = strrchr(path, '/');
 140                        if (file && !strcmp(file + 1, "konqueror")) {
 141                                char *new = xstrdup(path);
 142                                char *dest = strrchr(new, '/');
 143
 144                                /* strlen("konqueror") == strlen("kfmclient") */
 145                                strcpy(dest + 1, "kfmclient");
 146                                path = new;
 147                        }
 148                        if (file)
 149                                filename = file;
 150                } else
 151                        path = "kfmclient";
 152                strbuf_addf(&man_page, "man:%s(1)", page);
 153                execlp(path, filename, "newTab", man_page.buf, NULL);
 154                warning("failed to exec '%s': %s", path, strerror(errno));
 155        }
 156}
 157
 158static void exec_man_man(const char* path, const char *page)
 159{
 160        if (!path)
 161                path = "man";
 162        execlp(path, "man", page, NULL);
 163        warning("failed to exec '%s': %s", path, strerror(errno));
 164}
 165
 166static void exec_man_cmd(const char *cmd, const char *page)
 167{
 168        struct strbuf shell_cmd = STRBUF_INIT;
 169        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 170        execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 171        warning("failed to exec '%s': %s", cmd, strerror(errno));
 172}
 173
 174static void add_man_viewer(const char *name)
 175{
 176        struct man_viewer_list **p = &man_viewer_list;
 177        size_t len = strlen(name);
 178
 179        while (*p)
 180                p = &((*p)->next);
 181        *p = xcalloc(1, (sizeof(**p) + len + 1));
 182        strncpy((*p)->name, name, len);
 183}
 184
 185static int supported_man_viewer(const char *name, size_t len)
 186{
 187        return (!strncasecmp("man", name, len) ||
 188                !strncasecmp("woman", name, len) ||
 189                !strncasecmp("konqueror", name, len));
 190}
 191
 192static void do_add_man_viewer_info(const char *name,
 193                                   size_t len,
 194                                   const char *value)
 195{
 196        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 197
 198        strncpy(new->name, name, len);
 199        new->info = xstrdup(value);
 200        new->next = man_viewer_info_list;
 201        man_viewer_info_list = new;
 202}
 203
 204static int add_man_viewer_path(const char *name,
 205                               size_t len,
 206                               const char *value)
 207{
 208        if (supported_man_viewer(name, len))
 209                do_add_man_viewer_info(name, len, value);
 210        else
 211                warning("'%s': path for unsupported man viewer.\n"
 212                        "Please consider using 'man.<tool>.cmd' instead.",
 213                        name);
 214
 215        return 0;
 216}
 217
 218static int add_man_viewer_cmd(const char *name,
 219                              size_t len,
 220                              const char *value)
 221{
 222        if (supported_man_viewer(name, len))
 223                warning("'%s': cmd for supported man viewer.\n"
 224                        "Please consider using 'man.<tool>.path' instead.",
 225                        name);
 226        else
 227                do_add_man_viewer_info(name, len, value);
 228
 229        return 0;
 230}
 231
 232static int add_man_viewer_info(const char *var, const char *value)
 233{
 234        const char *name = var + 4;
 235        const char *subkey = strrchr(name, '.');
 236
 237        if (!subkey)
 238                return error("Config with no key for man viewer: %s", name);
 239
 240        if (!strcmp(subkey, ".path")) {
 241                if (!value)
 242                        return config_error_nonbool(var);
 243                return add_man_viewer_path(name, subkey - name, value);
 244        }
 245        if (!strcmp(subkey, ".cmd")) {
 246                if (!value)
 247                        return config_error_nonbool(var);
 248                return add_man_viewer_cmd(name, subkey - name, value);
 249        }
 250
 251        warning("'%s': unsupported man viewer sub key.", subkey);
 252        return 0;
 253}
 254
 255static int git_help_config(const char *var, const char *value, void *cb)
 256{
 257        if (!strcmp(var, "help.format")) {
 258                if (!value)
 259                        return config_error_nonbool(var);
 260                help_format = parse_help_format(value);
 261                return 0;
 262        }
 263        if (!strcmp(var, "man.viewer")) {
 264                if (!value)
 265                        return config_error_nonbool(var);
 266                add_man_viewer(value);
 267                return 0;
 268        }
 269        if (!prefixcmp(var, "man."))
 270                return add_man_viewer_info(var, value);
 271
 272        return git_default_config(var, value, cb);
 273}
 274
 275/* most GUI terminals set COLUMNS (although some don't export it) */
 276static int term_columns(void)
 277{
 278        char *col_string = getenv("COLUMNS");
 279        int n_cols;
 280
 281        if (col_string && (n_cols = atoi(col_string)) > 0)
 282                return n_cols;
 283
 284#ifdef TIOCGWINSZ
 285        {
 286                struct winsize ws;
 287                if (!ioctl(1, TIOCGWINSZ, &ws)) {
 288                        if (ws.ws_col)
 289                                return ws.ws_col;
 290                }
 291        }
 292#endif
 293
 294        return 80;
 295}
 296
 297static inline void mput_char(char c, unsigned int num)
 298{
 299        while(num--)
 300                putchar(c);
 301}
 302
 303static struct cmdnames {
 304        int alloc;
 305        int cnt;
 306        struct cmdname {
 307                size_t len;
 308                char name[1];
 309        } **names;
 310} main_cmds, other_cmds;
 311
 312static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 313{
 314        struct cmdname *ent = xmalloc(sizeof(*ent) + len);
 315
 316        ent->len = len;
 317        memcpy(ent->name, name, len);
 318        ent->name[len] = 0;
 319
 320        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 321        cmds->names[cmds->cnt++] = ent;
 322}
 323
 324static int cmdname_compare(const void *a_, const void *b_)
 325{
 326        struct cmdname *a = *(struct cmdname **)a_;
 327        struct cmdname *b = *(struct cmdname **)b_;
 328        return strcmp(a->name, b->name);
 329}
 330
 331static void uniq(struct cmdnames *cmds)
 332{
 333        int i, j;
 334
 335        if (!cmds->cnt)
 336                return;
 337
 338        for (i = j = 1; i < cmds->cnt; i++)
 339                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 340                        cmds->names[j++] = cmds->names[i];
 341
 342        cmds->cnt = j;
 343}
 344
 345static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 346{
 347        int ci, cj, ei;
 348        int cmp;
 349
 350        ci = cj = ei = 0;
 351        while (ci < cmds->cnt && ei < excludes->cnt) {
 352                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 353                if (cmp < 0)
 354                        cmds->names[cj++] = cmds->names[ci++];
 355                else if (cmp == 0)
 356                        ci++, ei++;
 357                else if (cmp > 0)
 358                        ei++;
 359        }
 360
 361        while (ci < cmds->cnt)
 362                cmds->names[cj++] = cmds->names[ci++];
 363
 364        cmds->cnt = cj;
 365}
 366
 367static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 368{
 369        int cols = 1, rows;
 370        int space = longest + 1; /* min 1 SP between words */
 371        int max_cols = term_columns() - 1; /* don't print *on* the edge */
 372        int i, j;
 373
 374        if (space < max_cols)
 375                cols = max_cols / space;
 376        rows = (cmds->cnt + cols - 1) / cols;
 377
 378        for (i = 0; i < rows; i++) {
 379                printf("  ");
 380
 381                for (j = 0; j < cols; j++) {
 382                        int n = j * rows + i;
 383                        int size = space;
 384                        if (n >= cmds->cnt)
 385                                break;
 386                        if (j == cols-1 || n + rows >= cmds->cnt)
 387                                size = 1;
 388                        printf("%-*s", size, cmds->names[n]->name);
 389                }
 390                putchar('\n');
 391        }
 392}
 393
 394static int is_executable(const char *name)
 395{
 396        struct stat st;
 397
 398        if (stat(name, &st) || /* stat, not lstat */
 399            !S_ISREG(st.st_mode))
 400                return 0;
 401
 402#ifdef __MINGW32__
 403        /* cannot trust the executable bit, peek into the file instead */
 404        char buf[3] = { 0 };
 405        int n;
 406        int fd = open(name, O_RDONLY);
 407        st.st_mode &= ~S_IXUSR;
 408        if (fd >= 0) {
 409                n = read(fd, buf, 2);
 410                if (n == 2)
 411                        /* DOS executables start with "MZ" */
 412                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 413                                st.st_mode |= S_IXUSR;
 414                close(fd);
 415        }
 416#endif
 417        return st.st_mode & S_IXUSR;
 418}
 419
 420static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 421                                         const char *path)
 422{
 423        unsigned int longest = 0;
 424        const char *prefix = "git-";
 425        int prefix_len = strlen(prefix);
 426        DIR *dir = opendir(path);
 427        struct dirent *de;
 428        struct strbuf buf = STRBUF_INIT;
 429        int len;
 430
 431        if (!dir)
 432                return 0;
 433
 434        strbuf_addf(&buf, "%s/", path);
 435        len = buf.len;
 436
 437        while ((de = readdir(dir)) != NULL) {
 438                int entlen;
 439
 440                if (prefixcmp(de->d_name, prefix))
 441                        continue;
 442
 443                strbuf_setlen(&buf, len);
 444                strbuf_addstr(&buf, de->d_name);
 445                if (!is_executable(buf.buf))
 446                        continue;
 447
 448                entlen = strlen(de->d_name) - prefix_len;
 449                if (has_extension(de->d_name, ".exe"))
 450                        entlen -= 4;
 451
 452                if (longest < entlen)
 453                        longest = entlen;
 454
 455                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 456        }
 457        closedir(dir);
 458        strbuf_release(&buf);
 459
 460        return longest;
 461}
 462
 463static unsigned int load_command_list(void)
 464{
 465        unsigned int longest = 0;
 466        unsigned int len;
 467        const char *env_path = getenv("PATH");
 468        char *paths, *path, *colon;
 469        const char *exec_path = git_exec_path();
 470
 471        if (exec_path)
 472                longest = list_commands_in_dir(&main_cmds, exec_path);
 473
 474        if (!env_path) {
 475                fprintf(stderr, "PATH not set\n");
 476                exit(1);
 477        }
 478
 479        path = paths = xstrdup(env_path);
 480        while (1) {
 481                if ((colon = strchr(path, PATH_SEP)))
 482                        *colon = 0;
 483
 484                len = list_commands_in_dir(&other_cmds, path);
 485                if (len > longest)
 486                        longest = len;
 487
 488                if (!colon)
 489                        break;
 490                path = colon + 1;
 491        }
 492        free(paths);
 493
 494        qsort(main_cmds.names, main_cmds.cnt,
 495              sizeof(*main_cmds.names), cmdname_compare);
 496        uniq(&main_cmds);
 497
 498        qsort(other_cmds.names, other_cmds.cnt,
 499              sizeof(*other_cmds.names), cmdname_compare);
 500        uniq(&other_cmds);
 501        exclude_cmds(&other_cmds, &main_cmds);
 502
 503        return longest;
 504}
 505
 506static void list_commands(void)
 507{
 508        unsigned int longest = load_command_list();
 509        const char *exec_path = git_exec_path();
 510
 511        if (main_cmds.cnt) {
 512                printf("available git commands in '%s'\n", exec_path);
 513                printf("----------------------------");
 514                mput_char('-', strlen(exec_path));
 515                putchar('\n');
 516                pretty_print_string_list(&main_cmds, longest);
 517                putchar('\n');
 518        }
 519
 520        if (other_cmds.cnt) {
 521                printf("git commands available from elsewhere on your $PATH\n");
 522                printf("---------------------------------------------------\n");
 523                pretty_print_string_list(&other_cmds, longest);
 524                putchar('\n');
 525        }
 526}
 527
 528void list_common_cmds_help(void)
 529{
 530        int i, longest = 0;
 531
 532        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 533                if (longest < strlen(common_cmds[i].name))
 534                        longest = strlen(common_cmds[i].name);
 535        }
 536
 537        puts("The most commonly used git commands are:");
 538        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 539                printf("   %s   ", common_cmds[i].name);
 540                mput_char(' ', longest - strlen(common_cmds[i].name));
 541                puts(common_cmds[i].help);
 542        }
 543}
 544
 545static int is_in_cmdlist(struct cmdnames *c, const char *s)
 546{
 547        int i;
 548        for (i = 0; i < c->cnt; i++)
 549                if (!strcmp(s, c->names[i]->name))
 550                        return 1;
 551        return 0;
 552}
 553
 554static int is_git_command(const char *s)
 555{
 556        load_command_list();
 557        return is_in_cmdlist(&main_cmds, s) ||
 558                is_in_cmdlist(&other_cmds, s);
 559}
 560
 561static const char *prepend(const char *prefix, const char *cmd)
 562{
 563        size_t pre_len = strlen(prefix);
 564        size_t cmd_len = strlen(cmd);
 565        char *p = xmalloc(pre_len + cmd_len + 1);
 566        memcpy(p, prefix, pre_len);
 567        strcpy(p + pre_len, cmd);
 568        return p;
 569}
 570
 571static const char *cmd_to_page(const char *git_cmd)
 572{
 573        if (!git_cmd)
 574                return "git";
 575        else if (!prefixcmp(git_cmd, "git"))
 576                return git_cmd;
 577        else if (is_git_command(git_cmd))
 578                return prepend("git-", git_cmd);
 579        else
 580                return prepend("git", git_cmd);
 581}
 582
 583static void setup_man_path(void)
 584{
 585        struct strbuf new_path;
 586        const char *old_path = getenv("MANPATH");
 587
 588        strbuf_init(&new_path, 0);
 589
 590        /* We should always put ':' after our path. If there is no
 591         * old_path, the ':' at the end will let 'man' to try
 592         * system-wide paths after ours to find the manual page. If
 593         * there is old_path, we need ':' as delimiter. */
 594        strbuf_addstr(&new_path, GIT_MAN_PATH);
 595        strbuf_addch(&new_path, ':');
 596        if (old_path)
 597                strbuf_addstr(&new_path, old_path);
 598
 599        setenv("MANPATH", new_path.buf, 1);
 600
 601        strbuf_release(&new_path);
 602}
 603
 604static void exec_viewer(const char *name, const char *page)
 605{
 606        const char *info = get_man_viewer_info(name);
 607
 608        if (!strcasecmp(name, "man"))
 609                exec_man_man(info, page);
 610        else if (!strcasecmp(name, "woman"))
 611                exec_woman_emacs(info, page);
 612        else if (!strcasecmp(name, "konqueror"))
 613                exec_man_konqueror(info, page);
 614        else if (info)
 615                exec_man_cmd(info, page);
 616        else
 617                warning("'%s': unknown man viewer.", name);
 618}
 619
 620static void show_man_page(const char *git_cmd)
 621{
 622        struct man_viewer_list *viewer;
 623        const char *page = cmd_to_page(git_cmd);
 624
 625        setup_man_path();
 626        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 627        {
 628                exec_viewer(viewer->name, page); /* will return when unable */
 629        }
 630        exec_viewer("man", page);
 631        die("no man viewer handled the request");
 632}
 633
 634static void show_info_page(const char *git_cmd)
 635{
 636        const char *page = cmd_to_page(git_cmd);
 637        setenv("INFOPATH", GIT_INFO_PATH, 1);
 638        execlp("info", "info", "gitman", page, NULL);
 639}
 640
 641static void get_html_page_path(struct strbuf *page_path, const char *page)
 642{
 643        struct stat st;
 644        const char *html_path = system_path(GIT_HTML_PATH);
 645
 646        /* Check that we have a git documentation directory. */
 647        if (stat(mkpath("%s/git.html", html_path), &st)
 648            || !S_ISREG(st.st_mode))
 649                die("'%s': not a documentation directory.", html_path);
 650
 651        strbuf_init(page_path, 0);
 652        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 653}
 654
 655/*
 656 * If open_html is not defined in a platform-specific way (see for
 657 * example compat/mingw.h), we use the script web--browse to display
 658 * HTML.
 659 */
 660#ifndef open_html
 661void open_html(const char *path)
 662{
 663        execl_git_cmd("web--browse", "-c", "help.browser", path, NULL);
 664}
 665#endif
 666
 667static void show_html_page(const char *git_cmd)
 668{
 669        const char *page = cmd_to_page(git_cmd);
 670        struct strbuf page_path; /* it leaks but we exec bellow */
 671
 672        get_html_page_path(&page_path, page);
 673
 674        open_html(page_path.buf);
 675}
 676
 677void help_unknown_cmd(const char *cmd)
 678{
 679        fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 680        exit(1);
 681}
 682
 683int cmd_version(int argc, const char **argv, const char *prefix)
 684{
 685        printf("git version %s\n", git_version_string);
 686        return 0;
 687}
 688
 689int cmd_help(int argc, const char **argv, const char *prefix)
 690{
 691        int nongit;
 692        const char *alias;
 693
 694        setup_git_directory_gently(&nongit);
 695        git_config(git_help_config, NULL);
 696
 697        argc = parse_options(argc, argv, builtin_help_options,
 698                        builtin_help_usage, 0);
 699
 700        if (show_all) {
 701                printf("usage: %s\n\n", git_usage_string);
 702                list_commands();
 703                printf("%s\n", git_more_info_string);
 704                return 0;
 705        }
 706
 707        if (!argv[0]) {
 708                printf("usage: %s\n\n", git_usage_string);
 709                list_common_cmds_help();
 710                printf("\n%s\n", git_more_info_string);
 711                return 0;
 712        }
 713
 714        alias = alias_lookup(argv[0]);
 715        if (alias && !is_git_command(argv[0])) {
 716                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 717                return 0;
 718        }
 719
 720        switch (help_format) {
 721        case HELP_FORMAT_MAN:
 722                show_man_page(argv[0]);
 723                break;
 724        case HELP_FORMAT_INFO:
 725                show_info_page(argv[0]);
 726                break;
 727        case HELP_FORMAT_WEB:
 728                show_html_page(argv[0]);
 729                break;
 730        }
 731
 732        return 0;
 733}