Andrew's git / gitweb.git / help.c
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help.con commit builtin-help: make some internal functions available to other builtins (940208a)
   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#include "help.h"
  13
  14static struct man_viewer_list {
  15        struct man_viewer_list *next;
  16        char name[FLEX_ARRAY];
  17} *man_viewer_list;
  18
  19static struct man_viewer_info_list {
  20        struct man_viewer_info_list *next;
  21        const char *info;
  22        char name[FLEX_ARRAY];
  23} *man_viewer_info_list;
  24
  25enum help_format {
  26        HELP_FORMAT_MAN,
  27        HELP_FORMAT_INFO,
  28        HELP_FORMAT_WEB,
  29};
  30
  31static int show_all = 0;
  32static enum help_format help_format = HELP_FORMAT_MAN;
  33static struct option builtin_help_options[] = {
  34        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  35        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  36        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  37                        HELP_FORMAT_WEB),
  38        OPT_SET_INT('i', "info", &help_format, "show info page",
  39                        HELP_FORMAT_INFO),
  40        OPT_END(),
  41};
  42
  43static const char * const builtin_help_usage[] = {
  44        "git help [--all] [--man|--web|--info] [command]",
  45        NULL
  46};
  47
  48static enum help_format parse_help_format(const char *format)
  49{
  50        if (!strcmp(format, "man"))
  51                return HELP_FORMAT_MAN;
  52        if (!strcmp(format, "info"))
  53                return HELP_FORMAT_INFO;
  54        if (!strcmp(format, "web") || !strcmp(format, "html"))
  55                return HELP_FORMAT_WEB;
  56        die("unrecognized help format '%s'", format);
  57}
  58
  59static const char *get_man_viewer_info(const char *name)
  60{
  61        struct man_viewer_info_list *viewer;
  62
  63        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  64        {
  65                if (!strcasecmp(name, viewer->name))
  66                        return viewer->info;
  67        }
  68        return NULL;
  69}
  70
  71static int check_emacsclient_version(void)
  72{
  73        struct strbuf buffer = STRBUF_INIT;
  74        struct child_process ec_process;
  75        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  76        int version;
  77
  78        /* emacsclient prints its version number on stderr */
  79        memset(&ec_process, 0, sizeof(ec_process));
  80        ec_process.argv = argv_ec;
  81        ec_process.err = -1;
  82        ec_process.stdout_to_stderr = 1;
  83        if (start_command(&ec_process)) {
  84                fprintf(stderr, "Failed to start emacsclient.\n");
  85                return -1;
  86        }
  87        strbuf_read(&buffer, ec_process.err, 20);
  88        close(ec_process.err);
  89
  90        /*
  91         * Don't bother checking return value, because "emacsclient --version"
  92         * seems to always exits with code 1.
  93         */
  94        finish_command(&ec_process);
  95
  96        if (prefixcmp(buffer.buf, "emacsclient")) {
  97                fprintf(stderr, "Failed to parse emacsclient version.\n");
  98                strbuf_release(&buffer);
  99                return -1;
 100        }
 101
 102        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 103        version = atoi(buffer.buf);
 104
 105        if (version < 22) {
 106                fprintf(stderr,
 107                        "emacsclient version '%d' too old (< 22).\n",
 108                        version);
 109                strbuf_release(&buffer);
 110                return -1;
 111        }
 112
 113        strbuf_release(&buffer);
 114        return 0;
 115}
 116
 117static void exec_woman_emacs(const char* path, const char *page)
 118{
 119        if (!check_emacsclient_version()) {
 120                /* This works only with emacsclient version >= 22. */
 121                struct strbuf man_page = STRBUF_INIT;
 122
 123                if (!path)
 124                        path = "emacsclient";
 125                strbuf_addf(&man_page, "(woman \"%s\")", page);
 126                execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 127                warning("failed to exec '%s': %s", path, strerror(errno));
 128        }
 129}
 130
 131static void exec_man_konqueror(const char* path, const char *page)
 132{
 133        const char *display = getenv("DISPLAY");
 134        if (display && *display) {
 135                struct strbuf man_page = STRBUF_INIT;
 136                const char *filename = "kfmclient";
 137
 138                /* It's simpler to launch konqueror using kfmclient. */
 139                if (path) {
 140                        const char *file = strrchr(path, '/');
 141                        if (file && !strcmp(file + 1, "konqueror")) {
 142                                char *new = xstrdup(path);
 143                                char *dest = strrchr(new, '/');
 144
 145                                /* strlen("konqueror") == strlen("kfmclient") */
 146                                strcpy(dest + 1, "kfmclient");
 147                                path = new;
 148                        }
 149                        if (file)
 150                                filename = file;
 151                } else
 152                        path = "kfmclient";
 153                strbuf_addf(&man_page, "man:%s(1)", page);
 154                execlp(path, filename, "newTab", man_page.buf, NULL);
 155                warning("failed to exec '%s': %s", path, strerror(errno));
 156        }
 157}
 158
 159static void exec_man_man(const char* path, const char *page)
 160{
 161        if (!path)
 162                path = "man";
 163        execlp(path, "man", page, NULL);
 164        warning("failed to exec '%s': %s", path, strerror(errno));
 165}
 166
 167static void exec_man_cmd(const char *cmd, const char *page)
 168{
 169        struct strbuf shell_cmd = STRBUF_INIT;
 170        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 171        execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 172        warning("failed to exec '%s': %s", cmd, strerror(errno));
 173}
 174
 175static void add_man_viewer(const char *name)
 176{
 177        struct man_viewer_list **p = &man_viewer_list;
 178        size_t len = strlen(name);
 179
 180        while (*p)
 181                p = &((*p)->next);
 182        *p = xcalloc(1, (sizeof(**p) + len + 1));
 183        strncpy((*p)->name, name, len);
 184}
 185
 186static int supported_man_viewer(const char *name, size_t len)
 187{
 188        return (!strncasecmp("man", name, len) ||
 189                !strncasecmp("woman", name, len) ||
 190                !strncasecmp("konqueror", name, len));
 191}
 192
 193static void do_add_man_viewer_info(const char *name,
 194                                   size_t len,
 195                                   const char *value)
 196{
 197        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 198
 199        strncpy(new->name, name, len);
 200        new->info = xstrdup(value);
 201        new->next = man_viewer_info_list;
 202        man_viewer_info_list = new;
 203}
 204
 205static int add_man_viewer_path(const char *name,
 206                               size_t len,
 207                               const char *value)
 208{
 209        if (supported_man_viewer(name, len))
 210                do_add_man_viewer_info(name, len, value);
 211        else
 212                warning("'%s': path for unsupported man viewer.\n"
 213                        "Please consider using 'man.<tool>.cmd' instead.",
 214                        name);
 215
 216        return 0;
 217}
 218
 219static int add_man_viewer_cmd(const char *name,
 220                              size_t len,
 221                              const char *value)
 222{
 223        if (supported_man_viewer(name, len))
 224                warning("'%s': cmd for supported man viewer.\n"
 225                        "Please consider using 'man.<tool>.path' instead.",
 226                        name);
 227        else
 228                do_add_man_viewer_info(name, len, value);
 229
 230        return 0;
 231}
 232
 233static int add_man_viewer_info(const char *var, const char *value)
 234{
 235        const char *name = var + 4;
 236        const char *subkey = strrchr(name, '.');
 237
 238        if (!subkey)
 239                return error("Config with no key for man viewer: %s", name);
 240
 241        if (!strcmp(subkey, ".path")) {
 242                if (!value)
 243                        return config_error_nonbool(var);
 244                return add_man_viewer_path(name, subkey - name, value);
 245        }
 246        if (!strcmp(subkey, ".cmd")) {
 247                if (!value)
 248                        return config_error_nonbool(var);
 249                return add_man_viewer_cmd(name, subkey - name, value);
 250        }
 251
 252        warning("'%s': unsupported man viewer sub key.", subkey);
 253        return 0;
 254}
 255
 256static int git_help_config(const char *var, const char *value, void *cb)
 257{
 258        if (!strcmp(var, "help.format")) {
 259                if (!value)
 260                        return config_error_nonbool(var);
 261                help_format = parse_help_format(value);
 262                return 0;
 263        }
 264        if (!strcmp(var, "man.viewer")) {
 265                if (!value)
 266                        return config_error_nonbool(var);
 267                add_man_viewer(value);
 268                return 0;
 269        }
 270        if (!prefixcmp(var, "man."))
 271                return add_man_viewer_info(var, value);
 272
 273        return git_default_config(var, value, cb);
 274}
 275
 276/* most GUI terminals set COLUMNS (although some don't export it) */
 277static int term_columns(void)
 278{
 279        char *col_string = getenv("COLUMNS");
 280        int n_cols;
 281
 282        if (col_string && (n_cols = atoi(col_string)) > 0)
 283                return n_cols;
 284
 285#ifdef TIOCGWINSZ
 286        {
 287                struct winsize ws;
 288                if (!ioctl(1, TIOCGWINSZ, &ws)) {
 289                        if (ws.ws_col)
 290                                return ws.ws_col;
 291                }
 292        }
 293#endif
 294
 295        return 80;
 296}
 297
 298static inline void mput_char(char c, unsigned int num)
 299{
 300        while(num--)
 301                putchar(c);
 302}
 303
 304struct cmdnames main_cmds, other_cmds;
 305
 306void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 307{
 308        struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
 309
 310        ent->len = len;
 311        memcpy(ent->name, name, len);
 312        ent->name[len] = 0;
 313
 314        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 315        cmds->names[cmds->cnt++] = ent;
 316}
 317
 318static int cmdname_compare(const void *a_, const void *b_)
 319{
 320        struct cmdname *a = *(struct cmdname **)a_;
 321        struct cmdname *b = *(struct cmdname **)b_;
 322        return strcmp(a->name, b->name);
 323}
 324
 325static void uniq(struct cmdnames *cmds)
 326{
 327        int i, j;
 328
 329        if (!cmds->cnt)
 330                return;
 331
 332        for (i = j = 1; i < cmds->cnt; i++)
 333                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 334                        cmds->names[j++] = cmds->names[i];
 335
 336        cmds->cnt = j;
 337}
 338
 339void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 340{
 341        int ci, cj, ei;
 342        int cmp;
 343
 344        ci = cj = ei = 0;
 345        while (ci < cmds->cnt && ei < excludes->cnt) {
 346                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 347                if (cmp < 0)
 348                        cmds->names[cj++] = cmds->names[ci++];
 349                else if (cmp == 0)
 350                        ci++, ei++;
 351                else if (cmp > 0)
 352                        ei++;
 353        }
 354
 355        while (ci < cmds->cnt)
 356                cmds->names[cj++] = cmds->names[ci++];
 357
 358        cmds->cnt = cj;
 359}
 360
 361static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 362{
 363        int cols = 1, rows;
 364        int space = longest + 1; /* min 1 SP between words */
 365        int max_cols = term_columns() - 1; /* don't print *on* the edge */
 366        int i, j;
 367
 368        if (space < max_cols)
 369                cols = max_cols / space;
 370        rows = (cmds->cnt + cols - 1) / cols;
 371
 372        for (i = 0; i < rows; i++) {
 373                printf("  ");
 374
 375                for (j = 0; j < cols; j++) {
 376                        int n = j * rows + i;
 377                        int size = space;
 378                        if (n >= cmds->cnt)
 379                                break;
 380                        if (j == cols-1 || n + rows >= cmds->cnt)
 381                                size = 1;
 382                        printf("%-*s", size, cmds->names[n]->name);
 383                }
 384                putchar('\n');
 385        }
 386}
 387
 388static int is_executable(const char *name)
 389{
 390        struct stat st;
 391
 392        if (stat(name, &st) || /* stat, not lstat */
 393            !S_ISREG(st.st_mode))
 394                return 0;
 395
 396#ifdef __MINGW32__
 397        /* cannot trust the executable bit, peek into the file instead */
 398        char buf[3] = { 0 };
 399        int n;
 400        int fd = open(name, O_RDONLY);
 401        st.st_mode &= ~S_IXUSR;
 402        if (fd >= 0) {
 403                n = read(fd, buf, 2);
 404                if (n == 2)
 405                        /* DOS executables start with "MZ" */
 406                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 407                                st.st_mode |= S_IXUSR;
 408                close(fd);
 409        }
 410#endif
 411        return st.st_mode & S_IXUSR;
 412}
 413
 414static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 415                                         const char *path,
 416                                         const char *prefix)
 417{
 418        unsigned int longest = 0;
 419        int prefix_len;
 420        DIR *dir = opendir(path);
 421        struct dirent *de;
 422        struct strbuf buf = STRBUF_INIT;
 423        int len;
 424
 425        if (!dir)
 426                return 0;
 427        if (!prefix)
 428                prefix = "git-";
 429        prefix_len = strlen(prefix);
 430
 431        strbuf_addf(&buf, "%s/", path);
 432        len = buf.len;
 433
 434        while ((de = readdir(dir)) != NULL) {
 435                int entlen;
 436
 437                if (prefixcmp(de->d_name, prefix))
 438                        continue;
 439
 440                strbuf_setlen(&buf, len);
 441                strbuf_addstr(&buf, de->d_name);
 442                if (!is_executable(buf.buf))
 443                        continue;
 444
 445                entlen = strlen(de->d_name) - prefix_len;
 446                if (has_extension(de->d_name, ".exe"))
 447                        entlen -= 4;
 448
 449                if (longest < entlen)
 450                        longest = entlen;
 451
 452                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 453        }
 454        closedir(dir);
 455        strbuf_release(&buf);
 456
 457        return longest;
 458}
 459
 460unsigned int load_command_list(const char *prefix,
 461                struct cmdnames *main_cmds,
 462                struct cmdnames *other_cmds)
 463{
 464        unsigned int longest = 0;
 465        unsigned int len;
 466        const char *env_path = getenv("PATH");
 467        char *paths, *path, *colon;
 468        const char *exec_path = git_exec_path();
 469
 470        if (exec_path)
 471                longest = list_commands_in_dir(main_cmds, exec_path, prefix);
 472
 473        if (!env_path) {
 474                fprintf(stderr, "PATH not set\n");
 475                exit(1);
 476        }
 477
 478        path = paths = xstrdup(env_path);
 479        while (1) {
 480                if ((colon = strchr(path, PATH_SEP)))
 481                        *colon = 0;
 482
 483                len = list_commands_in_dir(other_cmds, path, prefix);
 484                if (len > longest)
 485                        longest = len;
 486
 487                if (!colon)
 488                        break;
 489                path = colon + 1;
 490        }
 491        free(paths);
 492
 493        qsort(main_cmds->names, main_cmds->cnt,
 494              sizeof(*main_cmds->names), cmdname_compare);
 495        uniq(main_cmds);
 496
 497        qsort(other_cmds->names, other_cmds->cnt,
 498              sizeof(*other_cmds->names), cmdname_compare);
 499        uniq(other_cmds);
 500        exclude_cmds(other_cmds, main_cmds);
 501
 502        return longest;
 503}
 504
 505void list_commands(const char *title, unsigned int longest,
 506                struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 507{
 508        const char *exec_path = git_exec_path();
 509
 510        if (main_cmds->cnt) {
 511                printf("available %s in '%s'\n", title, exec_path);
 512                printf("----------------");
 513                mput_char('-', strlen(title) + strlen(exec_path));
 514                putchar('\n');
 515                pretty_print_string_list(main_cmds, longest);
 516                putchar('\n');
 517        }
 518
 519        if (other_cmds->cnt) {
 520                printf("%s available from elsewhere on your $PATH\n", title);
 521                printf("---------------------------------------");
 522                mput_char('-', strlen(title));
 523                putchar('\n');
 524                pretty_print_string_list(other_cmds, longest);
 525                putchar('\n');
 526        }
 527}
 528
 529void list_common_cmds_help(void)
 530{
 531        int i, longest = 0;
 532
 533        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 534                if (longest < strlen(common_cmds[i].name))
 535                        longest = strlen(common_cmds[i].name);
 536        }
 537
 538        puts("The most commonly used git commands are:");
 539        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 540                printf("   %s   ", common_cmds[i].name);
 541                mput_char(' ', longest - strlen(common_cmds[i].name));
 542                puts(common_cmds[i].help);
 543        }
 544}
 545
 546int is_in_cmdlist(struct cmdnames *c, const char *s)
 547{
 548        int i;
 549        for (i = 0; i < c->cnt; i++)
 550                if (!strcmp(s, c->names[i]->name))
 551                        return 1;
 552        return 0;
 553}
 554
 555static int is_git_command(const char *s)
 556{
 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                unsigned int longest = load_command_list("git-", &main_cmds, &other_cmds);
 702                printf("usage: %s\n\n", git_usage_string);
 703                list_commands("git commands", longest, &main_cmds, &other_cmds);
 704                printf("%s\n", git_more_info_string);
 705                return 0;
 706        }
 707
 708        if (!argv[0]) {
 709                printf("usage: %s\n\n", git_usage_string);
 710                list_common_cmds_help();
 711                printf("\n%s\n", git_more_info_string);
 712                return 0;
 713        }
 714
 715        alias = alias_lookup(argv[0]);
 716        if (alias && !is_git_command(argv[0])) {
 717                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 718                return 0;
 719        }
 720
 721        switch (help_format) {
 722        case HELP_FORMAT_MAN:
 723                show_man_page(argv[0]);
 724                break;
 725        case HELP_FORMAT_INFO:
 726                show_info_page(argv[0]);
 727                break;
 728        case HELP_FORMAT_WEB:
 729                show_html_page(argv[0]);
 730                break;
 731        }
 732
 733        return 0;
 734}