Andrew's git / gitweb.git / help.c
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help.con commit Merge branch 'maint' (68951af)
   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        void (*exec)(const char *);
  15        struct man_viewer_list *next;
  16} *man_viewer_list;
  17
  18enum help_format {
  19        HELP_FORMAT_MAN,
  20        HELP_FORMAT_INFO,
  21        HELP_FORMAT_WEB,
  22};
  23
  24static int show_all = 0;
  25static enum help_format help_format = HELP_FORMAT_MAN;
  26static struct option builtin_help_options[] = {
  27        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  28        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  29        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  30                        HELP_FORMAT_WEB),
  31        OPT_SET_INT('i', "info", &help_format, "show info page",
  32                        HELP_FORMAT_INFO),
  33        OPT_END(),
  34};
  35
  36static const char * const builtin_help_usage[] = {
  37        "git-help [--all] [--man|--web|--info] [command]",
  38        NULL
  39};
  40
  41static enum help_format parse_help_format(const char *format)
  42{
  43        if (!strcmp(format, "man"))
  44                return HELP_FORMAT_MAN;
  45        if (!strcmp(format, "info"))
  46                return HELP_FORMAT_INFO;
  47        if (!strcmp(format, "web") || !strcmp(format, "html"))
  48                return HELP_FORMAT_WEB;
  49        die("unrecognized help format '%s'", format);
  50}
  51
  52static int check_emacsclient_version(void)
  53{
  54        struct strbuf buffer = STRBUF_INIT;
  55        struct child_process ec_process;
  56        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  57        int version;
  58
  59        /* emacsclient prints its version number on stderr */
  60        memset(&ec_process, 0, sizeof(ec_process));
  61        ec_process.argv = argv_ec;
  62        ec_process.err = -1;
  63        ec_process.stdout_to_stderr = 1;
  64        if (start_command(&ec_process)) {
  65                fprintf(stderr, "Failed to start emacsclient.\n");
  66                return -1;
  67        }
  68        strbuf_read(&buffer, ec_process.err, 20);
  69        close(ec_process.err);
  70
  71        /*
  72         * Don't bother checking return value, because "emacsclient --version"
  73         * seems to always exits with code 1.
  74         */
  75        finish_command(&ec_process);
  76
  77        if (prefixcmp(buffer.buf, "emacsclient")) {
  78                fprintf(stderr, "Failed to parse emacsclient version.\n");
  79                strbuf_release(&buffer);
  80                return -1;
  81        }
  82
  83        strbuf_remove(&buffer, 0, strlen("emacsclient"));
  84        version = atoi(buffer.buf);
  85
  86        if (version < 22) {
  87                fprintf(stderr,
  88                        "emacsclient version '%d' too old (< 22).\n",
  89                        version);
  90                strbuf_release(&buffer);
  91                return -1;
  92        }
  93
  94        strbuf_release(&buffer);
  95        return 0;
  96}
  97
  98static void exec_woman_emacs(const char *page)
  99{
 100        if (!check_emacsclient_version()) {
 101                /* This works only with emacsclient version >= 22. */
 102                struct strbuf man_page = STRBUF_INIT;
 103                strbuf_addf(&man_page, "(woman \"%s\")", page);
 104                execlp("emacsclient", "emacsclient", "-e", man_page.buf, NULL);
 105        }
 106}
 107
 108static void exec_man_konqueror(const char *page)
 109{
 110        const char *display = getenv("DISPLAY");
 111        if (display && *display) {
 112                struct strbuf man_page = STRBUF_INIT;
 113                strbuf_addf(&man_page, "man:%s(1)", page);
 114                execlp("kfmclient", "kfmclient", "newTab", man_page.buf, NULL);
 115        }
 116}
 117
 118static void exec_man_man(const char *page)
 119{
 120        execlp("man", "man", page, NULL);
 121}
 122
 123static void do_add_man_viewer(void (*exec)(const char *))
 124{
 125        struct man_viewer_list **p = &man_viewer_list;
 126
 127        while (*p)
 128                p = &((*p)->next);
 129        *p = xmalloc(sizeof(**p));
 130        (*p)->next = NULL;
 131        (*p)->exec = exec;
 132}
 133
 134static int add_man_viewer(const char *value)
 135{
 136        if (!strcasecmp(value, "man"))
 137                do_add_man_viewer(exec_man_man);
 138        else if (!strcasecmp(value, "woman"))
 139                do_add_man_viewer(exec_woman_emacs);
 140        else if (!strcasecmp(value, "konqueror"))
 141                do_add_man_viewer(exec_man_konqueror);
 142        else
 143                warning("'%s': unsupported man viewer.", value);
 144
 145        return 0;
 146}
 147
 148static int git_help_config(const char *var, const char *value)
 149{
 150        if (!strcmp(var, "help.format")) {
 151                if (!value)
 152                        return config_error_nonbool(var);
 153                help_format = parse_help_format(value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "man.viewer")) {
 157                if (!value)
 158                        return config_error_nonbool(var);
 159                return add_man_viewer(value);
 160        }
 161        return git_default_config(var, value);
 162}
 163
 164/* most GUI terminals set COLUMNS (although some don't export it) */
 165static int term_columns(void)
 166{
 167        char *col_string = getenv("COLUMNS");
 168        int n_cols;
 169
 170        if (col_string && (n_cols = atoi(col_string)) > 0)
 171                return n_cols;
 172
 173#ifdef TIOCGWINSZ
 174        {
 175                struct winsize ws;
 176                if (!ioctl(1, TIOCGWINSZ, &ws)) {
 177                        if (ws.ws_col)
 178                                return ws.ws_col;
 179                }
 180        }
 181#endif
 182
 183        return 80;
 184}
 185
 186static inline void mput_char(char c, unsigned int num)
 187{
 188        while(num--)
 189                putchar(c);
 190}
 191
 192static struct cmdnames {
 193        int alloc;
 194        int cnt;
 195        struct cmdname {
 196                size_t len;
 197                char name[1];
 198        } **names;
 199} main_cmds, other_cmds;
 200
 201static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 202{
 203        struct cmdname *ent = xmalloc(sizeof(*ent) + len);
 204
 205        ent->len = len;
 206        memcpy(ent->name, name, len);
 207        ent->name[len] = 0;
 208
 209        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
 210        cmds->names[cmds->cnt++] = ent;
 211}
 212
 213static int cmdname_compare(const void *a_, const void *b_)
 214{
 215        struct cmdname *a = *(struct cmdname **)a_;
 216        struct cmdname *b = *(struct cmdname **)b_;
 217        return strcmp(a->name, b->name);
 218}
 219
 220static void uniq(struct cmdnames *cmds)
 221{
 222        int i, j;
 223
 224        if (!cmds->cnt)
 225                return;
 226
 227        for (i = j = 1; i < cmds->cnt; i++)
 228                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 229                        cmds->names[j++] = cmds->names[i];
 230
 231        cmds->cnt = j;
 232}
 233
 234static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 235{
 236        int ci, cj, ei;
 237        int cmp;
 238
 239        ci = cj = ei = 0;
 240        while (ci < cmds->cnt && ei < excludes->cnt) {
 241                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 242                if (cmp < 0)
 243                        cmds->names[cj++] = cmds->names[ci++];
 244                else if (cmp == 0)
 245                        ci++, ei++;
 246                else if (cmp > 0)
 247                        ei++;
 248        }
 249
 250        while (ci < cmds->cnt)
 251                cmds->names[cj++] = cmds->names[ci++];
 252
 253        cmds->cnt = cj;
 254}
 255
 256static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 257{
 258        int cols = 1, rows;
 259        int space = longest + 1; /* min 1 SP between words */
 260        int max_cols = term_columns() - 1; /* don't print *on* the edge */
 261        int i, j;
 262
 263        if (space < max_cols)
 264                cols = max_cols / space;
 265        rows = (cmds->cnt + cols - 1) / cols;
 266
 267        for (i = 0; i < rows; i++) {
 268                printf("  ");
 269
 270                for (j = 0; j < cols; j++) {
 271                        int n = j * rows + i;
 272                        int size = space;
 273                        if (n >= cmds->cnt)
 274                                break;
 275                        if (j == cols-1 || n + rows >= cmds->cnt)
 276                                size = 1;
 277                        printf("%-*s", size, cmds->names[n]->name);
 278                }
 279                putchar('\n');
 280        }
 281}
 282
 283static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 284                                         const char *path)
 285{
 286        unsigned int longest = 0;
 287        const char *prefix = "git-";
 288        int prefix_len = strlen(prefix);
 289        DIR *dir = opendir(path);
 290        struct dirent *de;
 291
 292        if (!dir || chdir(path))
 293                return 0;
 294
 295        while ((de = readdir(dir)) != NULL) {
 296                struct stat st;
 297                int entlen;
 298
 299                if (prefixcmp(de->d_name, prefix))
 300                        continue;
 301
 302                if (stat(de->d_name, &st) || /* stat, not lstat */
 303                    !S_ISREG(st.st_mode) ||
 304                    !(st.st_mode & S_IXUSR))
 305                        continue;
 306
 307                entlen = strlen(de->d_name) - prefix_len;
 308                if (has_extension(de->d_name, ".exe"))
 309                        entlen -= 4;
 310
 311                if (longest < entlen)
 312                        longest = entlen;
 313
 314                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 315        }
 316        closedir(dir);
 317
 318        return longest;
 319}
 320
 321static unsigned int load_command_list(void)
 322{
 323        unsigned int longest = 0;
 324        unsigned int len;
 325        const char *env_path = getenv("PATH");
 326        char *paths, *path, *colon;
 327        const char *exec_path = git_exec_path();
 328
 329        if (exec_path)
 330                longest = list_commands_in_dir(&main_cmds, exec_path);
 331
 332        if (!env_path) {
 333                fprintf(stderr, "PATH not set\n");
 334                exit(1);
 335        }
 336
 337        path = paths = xstrdup(env_path);
 338        while (1) {
 339                if ((colon = strchr(path, ':')))
 340                        *colon = 0;
 341
 342                len = list_commands_in_dir(&other_cmds, path);
 343                if (len > longest)
 344                        longest = len;
 345
 346                if (!colon)
 347                        break;
 348                path = colon + 1;
 349        }
 350        free(paths);
 351
 352        qsort(main_cmds.names, main_cmds.cnt,
 353              sizeof(*main_cmds.names), cmdname_compare);
 354        uniq(&main_cmds);
 355
 356        qsort(other_cmds.names, other_cmds.cnt,
 357              sizeof(*other_cmds.names), cmdname_compare);
 358        uniq(&other_cmds);
 359        exclude_cmds(&other_cmds, &main_cmds);
 360
 361        return longest;
 362}
 363
 364static void list_commands(void)
 365{
 366        unsigned int longest = load_command_list();
 367        const char *exec_path = git_exec_path();
 368
 369        if (main_cmds.cnt) {
 370                printf("available git commands in '%s'\n", exec_path);
 371                printf("----------------------------");
 372                mput_char('-', strlen(exec_path));
 373                putchar('\n');
 374                pretty_print_string_list(&main_cmds, longest);
 375                putchar('\n');
 376        }
 377
 378        if (other_cmds.cnt) {
 379                printf("git commands available from elsewhere on your $PATH\n");
 380                printf("---------------------------------------------------\n");
 381                pretty_print_string_list(&other_cmds, longest);
 382                putchar('\n');
 383        }
 384}
 385
 386void list_common_cmds_help(void)
 387{
 388        int i, longest = 0;
 389
 390        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 391                if (longest < strlen(common_cmds[i].name))
 392                        longest = strlen(common_cmds[i].name);
 393        }
 394
 395        puts("The most commonly used git commands are:");
 396        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 397                printf("   %s   ", common_cmds[i].name);
 398                mput_char(' ', longest - strlen(common_cmds[i].name));
 399                puts(common_cmds[i].help);
 400        }
 401}
 402
 403static int is_in_cmdlist(struct cmdnames *c, const char *s)
 404{
 405        int i;
 406        for (i = 0; i < c->cnt; i++)
 407                if (!strcmp(s, c->names[i]->name))
 408                        return 1;
 409        return 0;
 410}
 411
 412static int is_git_command(const char *s)
 413{
 414        load_command_list();
 415        return is_in_cmdlist(&main_cmds, s) ||
 416                is_in_cmdlist(&other_cmds, s);
 417}
 418
 419static const char *cmd_to_page(const char *git_cmd)
 420{
 421        if (!git_cmd)
 422                return "git";
 423        else if (!prefixcmp(git_cmd, "git"))
 424                return git_cmd;
 425        else {
 426                int page_len = strlen(git_cmd) + 4;
 427                char *p = xmalloc(page_len + 1);
 428                strcpy(p, "git-");
 429                strcpy(p + 4, git_cmd);
 430                p[page_len] = 0;
 431                return p;
 432        }
 433}
 434
 435static void setup_man_path(void)
 436{
 437        struct strbuf new_path;
 438        const char *old_path = getenv("MANPATH");
 439
 440        strbuf_init(&new_path, 0);
 441
 442        /* We should always put ':' after our path. If there is no
 443         * old_path, the ':' at the end will let 'man' to try
 444         * system-wide paths after ours to find the manual page. If
 445         * there is old_path, we need ':' as delimiter. */
 446        strbuf_addstr(&new_path, GIT_MAN_PATH);
 447        strbuf_addch(&new_path, ':');
 448        if (old_path)
 449                strbuf_addstr(&new_path, old_path);
 450
 451        setenv("MANPATH", new_path.buf, 1);
 452
 453        strbuf_release(&new_path);
 454}
 455
 456static void show_man_page(const char *git_cmd)
 457{
 458        struct man_viewer_list *viewer;
 459        const char *page = cmd_to_page(git_cmd);
 460
 461        setup_man_path();
 462        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 463        {
 464                viewer->exec(page); /* will return when unable */
 465        }
 466        exec_man_man(page);
 467        die("no man viewer handled the request");
 468}
 469
 470static void show_info_page(const char *git_cmd)
 471{
 472        const char *page = cmd_to_page(git_cmd);
 473        setenv("INFOPATH", GIT_INFO_PATH, 1);
 474        execlp("info", "info", "gitman", page, NULL);
 475}
 476
 477static void get_html_page_path(struct strbuf *page_path, const char *page)
 478{
 479        struct stat st;
 480
 481        /* Check that we have a git documentation directory. */
 482        if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
 483                die("'%s': not a documentation directory.", GIT_HTML_PATH);
 484
 485        strbuf_init(page_path, 0);
 486        strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
 487}
 488
 489static void show_html_page(const char *git_cmd)
 490{
 491        const char *page = cmd_to_page(git_cmd);
 492        struct strbuf page_path; /* it leaks but we exec bellow */
 493
 494        get_html_page_path(&page_path, page);
 495
 496        execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
 497}
 498
 499void help_unknown_cmd(const char *cmd)
 500{
 501        fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 502        exit(1);
 503}
 504
 505int cmd_version(int argc, const char **argv, const char *prefix)
 506{
 507        printf("git version %s\n", git_version_string);
 508        return 0;
 509}
 510
 511int cmd_help(int argc, const char **argv, const char *prefix)
 512{
 513        int nongit;
 514        const char *alias;
 515
 516        setup_git_directory_gently(&nongit);
 517        git_config(git_help_config);
 518
 519        argc = parse_options(argc, argv, builtin_help_options,
 520                        builtin_help_usage, 0);
 521
 522        if (show_all) {
 523                printf("usage: %s\n\n", git_usage_string);
 524                list_commands();
 525                return 0;
 526        }
 527
 528        if (!argv[0]) {
 529                printf("usage: %s\n\n", git_usage_string);
 530                list_common_cmds_help();
 531                return 0;
 532        }
 533
 534        alias = alias_lookup(argv[0]);
 535        if (alias && !is_git_command(argv[0])) {
 536                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 537                return 0;
 538        }
 539
 540        switch (help_format) {
 541        case HELP_FORMAT_MAN:
 542                show_man_page(argv[0]);
 543                break;
 544        case HELP_FORMAT_INFO:
 545                show_info_page(argv[0]);
 546                break;
 547        case HELP_FORMAT_WEB:
 548                show_html_page(argv[0]);
 549                break;
 550        }
 551
 552        return 0;
 553}