Andrew's git - gitweb.git/blob

   1/*
   2 * builtin-help.c
   3 *
   4 * Builtin help command
   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_NONE,
  27        HELP_FORMAT_MAN,
  28        HELP_FORMAT_INFO,
  29        HELP_FORMAT_WEB,
  30};
  31
  32static int show_all = 0;
  33static enum help_format help_format = HELP_FORMAT_NONE;
  34static struct option builtin_help_options[] = {
  35        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  36        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  37        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  38                        HELP_FORMAT_WEB),
  39        OPT_SET_INT('i', "info", &help_format, "show info page",
  40                        HELP_FORMAT_INFO),
  41        OPT_END(),
  42};
  43
  44static const char * const builtin_help_usage[] = {
  45        "git help [--all] [--man|--web|--info] [command]",
  46        NULL
  47};
  48
  49static enum help_format parse_help_format(const char *format)
  50{
  51        if (!strcmp(format, "man"))
  52                return HELP_FORMAT_MAN;
  53        if (!strcmp(format, "info"))
  54                return HELP_FORMAT_INFO;
  55        if (!strcmp(format, "web") || !strcmp(format, "html"))
  56                return HELP_FORMAT_WEB;
  57        die("unrecognized help format '%s'", format);
  58}
  59
  60static const char *get_man_viewer_info(const char *name)
  61{
  62        struct man_viewer_info_list *viewer;
  63
  64        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  65        {
  66                if (!strcasecmp(name, viewer->name))
  67                        return viewer->info;
  68        }
  69        return NULL;
  70}
  71
  72static int check_emacsclient_version(void)
  73{
  74        struct strbuf buffer = STRBUF_INIT;
  75        struct child_process ec_process;
  76        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  77        int version;
  78
  79        /* emacsclient prints its version number on stderr */
  80        memset(&ec_process, 0, sizeof(ec_process));
  81        ec_process.argv = argv_ec;
  82        ec_process.err = -1;
  83        ec_process.stdout_to_stderr = 1;
  84        if (start_command(&ec_process))
  85                return error("Failed to start emacsclient.");
  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                strbuf_release(&buffer);
  98                return error("Failed to parse emacsclient version.");
  99        }
 100
 101        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 102        version = atoi(buffer.buf);
 103
 104        if (version < 22) {
 105                strbuf_release(&buffer);
 106                return error("emacsclient version '%d' too old (< 22).",
 107                        version);
 108        }
 109
 110        strbuf_release(&buffer);
 111        return 0;
 112}
 113
 114static void exec_woman_emacs(const char *path, const char *page)
 115{
 116        if (!check_emacsclient_version()) {
 117                /* This works only with emacsclient version >= 22. */
 118                struct strbuf man_page = STRBUF_INIT;
 119
 120                if (!path)
 121                        path = "emacsclient";
 122                strbuf_addf(&man_page, "(woman \"%s\")", page);
 123                execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 124                warning("failed to exec '%s': %s", path, strerror(errno));
 125        }
 126}
 127
 128static void exec_man_konqueror(const char *path, const char *page)
 129{
 130        const char *display = getenv("DISPLAY");
 131        if (display && *display) {
 132                struct strbuf man_page = STRBUF_INIT;
 133                const char *filename = "kfmclient";
 134
 135                /* It's simpler to launch konqueror using kfmclient. */
 136                if (path) {
 137                        const char *file = strrchr(path, '/');
 138                        if (file && !strcmp(file + 1, "konqueror")) {
 139                                char *new = xstrdup(path);
 140                                char *dest = strrchr(new, '/');
 141
 142                                /* strlen("konqueror") == strlen("kfmclient") */
 143                                strcpy(dest + 1, "kfmclient");
 144                                path = new;
 145                        }
 146                        if (file)
 147                                filename = file;
 148                } else
 149                        path = "kfmclient";
 150                strbuf_addf(&man_page, "man:%s(1)", page);
 151                execlp(path, filename, "newTab", man_page.buf, NULL);
 152                warning("failed to exec '%s': %s", path, strerror(errno));
 153        }
 154}
 155
 156static void exec_man_man(const char *path, const char *page)
 157{
 158        if (!path)
 159                path = "man";
 160        execlp(path, "man", page, NULL);
 161        warning("failed to exec '%s': %s", path, strerror(errno));
 162}
 163
 164static void exec_man_cmd(const char *cmd, const char *page)
 165{
 166        struct strbuf shell_cmd = STRBUF_INIT;
 167        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 168        execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 169        warning("failed to exec '%s': %s", cmd, strerror(errno));
 170}
 171
 172static void add_man_viewer(const char *name)
 173{
 174        struct man_viewer_list **p = &man_viewer_list;
 175        size_t len = strlen(name);
 176
 177        while (*p)
 178                p = &((*p)->next);
 179        *p = xcalloc(1, (sizeof(**p) + len + 1));
 180        strncpy((*p)->name, name, len);
 181}
 182
 183static int supported_man_viewer(const char *name, size_t len)
 184{
 185        return (!strncasecmp("man", name, len) ||
 186                !strncasecmp("woman", name, len) ||
 187                !strncasecmp("konqueror", name, len));
 188}
 189
 190static void do_add_man_viewer_info(const char *name,
 191                                   size_t len,
 192                                   const char *value)
 193{
 194        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 195
 196        strncpy(new->name, name, len);
 197        new->info = xstrdup(value);
 198        new->next = man_viewer_info_list;
 199        man_viewer_info_list = new;
 200}
 201
 202static int add_man_viewer_path(const char *name,
 203                               size_t len,
 204                               const char *value)
 205{
 206        if (supported_man_viewer(name, len))
 207                do_add_man_viewer_info(name, len, value);
 208        else
 209                warning("'%s': path for unsupported man viewer.\n"
 210                        "Please consider using 'man.<tool>.cmd' instead.",
 211                        name);
 212
 213        return 0;
 214}
 215
 216static int add_man_viewer_cmd(const char *name,
 217                              size_t len,
 218                              const char *value)
 219{
 220        if (supported_man_viewer(name, len))
 221                warning("'%s': cmd for supported man viewer.\n"
 222                        "Please consider using 'man.<tool>.path' instead.",
 223                        name);
 224        else
 225                do_add_man_viewer_info(name, len, value);
 226
 227        return 0;
 228}
 229
 230static int add_man_viewer_info(const char *var, const char *value)
 231{
 232        const char *name = var + 4;
 233        const char *subkey = strrchr(name, '.');
 234
 235        if (!subkey)
 236                return 0;
 237
 238        if (!strcmp(subkey, ".path")) {
 239                if (!value)
 240                        return config_error_nonbool(var);
 241                return add_man_viewer_path(name, subkey - name, value);
 242        }
 243        if (!strcmp(subkey, ".cmd")) {
 244                if (!value)
 245                        return config_error_nonbool(var);
 246                return add_man_viewer_cmd(name, subkey - name, value);
 247        }
 248
 249        return 0;
 250}
 251
 252static int git_help_config(const char *var, const char *value, void *cb)
 253{
 254        if (!strcmp(var, "help.format")) {
 255                if (!value)
 256                        return config_error_nonbool(var);
 257                help_format = parse_help_format(value);
 258                return 0;
 259        }
 260        if (!strcmp(var, "man.viewer")) {
 261                if (!value)
 262                        return config_error_nonbool(var);
 263                add_man_viewer(value);
 264                return 0;
 265        }
 266        if (!prefixcmp(var, "man."))
 267                return add_man_viewer_info(var, value);
 268
 269        return git_default_config(var, value, cb);
 270}
 271
 272static struct cmdnames main_cmds, other_cmds;
 273
 274void list_common_cmds_help(void)
 275{
 276        int i, longest = 0;
 277
 278        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 279                if (longest < strlen(common_cmds[i].name))
 280                        longest = strlen(common_cmds[i].name);
 281        }
 282
 283        puts("The most commonly used git commands are:");
 284        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 285                printf("   %s   ", common_cmds[i].name);
 286                mput_char(' ', longest - strlen(common_cmds[i].name));
 287                puts(common_cmds[i].help);
 288        }
 289}
 290
 291static int is_git_command(const char *s)
 292{
 293        return is_in_cmdlist(&main_cmds, s) ||
 294                is_in_cmdlist(&other_cmds, s);
 295}
 296
 297static const char *prepend(const char *prefix, const char *cmd)
 298{
 299        size_t pre_len = strlen(prefix);
 300        size_t cmd_len = strlen(cmd);
 301        char *p = xmalloc(pre_len + cmd_len + 1);
 302        memcpy(p, prefix, pre_len);
 303        strcpy(p + pre_len, cmd);
 304        return p;
 305}
 306
 307static const char *cmd_to_page(const char *git_cmd)
 308{
 309        if (!git_cmd)
 310                return "git";
 311        else if (!prefixcmp(git_cmd, "git"))
 312                return git_cmd;
 313        else if (is_git_command(git_cmd))
 314                return prepend("git-", git_cmd);
 315        else
 316                return prepend("git", git_cmd);
 317}
 318
 319static void setup_man_path(void)
 320{
 321        struct strbuf new_path = STRBUF_INIT;
 322        const char *old_path = getenv("MANPATH");
 323
 324        /* We should always put ':' after our path. If there is no
 325         * old_path, the ':' at the end will let 'man' to try
 326         * system-wide paths after ours to find the manual page. If
 327         * there is old_path, we need ':' as delimiter. */
 328        strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
 329        strbuf_addch(&new_path, ':');
 330        if (old_path)
 331                strbuf_addstr(&new_path, old_path);
 332
 333        setenv("MANPATH", new_path.buf, 1);
 334
 335        strbuf_release(&new_path);
 336}
 337
 338static void exec_viewer(const char *name, const char *page)
 339{
 340        const char *info = get_man_viewer_info(name);
 341
 342        if (!strcasecmp(name, "man"))
 343                exec_man_man(info, page);
 344        else if (!strcasecmp(name, "woman"))
 345                exec_woman_emacs(info, page);
 346        else if (!strcasecmp(name, "konqueror"))
 347                exec_man_konqueror(info, page);
 348        else if (info)
 349                exec_man_cmd(info, page);
 350        else
 351                warning("'%s': unknown man viewer.", name);
 352}
 353
 354static void show_man_page(const char *git_cmd)
 355{
 356        struct man_viewer_list *viewer;
 357        const char *page = cmd_to_page(git_cmd);
 358        const char *fallback = getenv("GIT_MAN_VIEWER");
 359
 360        setup_man_path();
 361        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 362        {
 363                exec_viewer(viewer->name, page); /* will return when unable */
 364        }
 365        if (fallback)
 366                exec_viewer(fallback, page);
 367        exec_viewer("man", page);
 368        die("no man viewer handled the request");
 369}
 370
 371static void show_info_page(const char *git_cmd)
 372{
 373        const char *page = cmd_to_page(git_cmd);
 374        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 375        execlp("info", "info", "gitman", page, NULL);
 376        die("no info viewer handled the request");
 377}
 378
 379static void get_html_page_path(struct strbuf *page_path, const char *page)
 380{
 381        struct stat st;
 382        const char *html_path = system_path(GIT_HTML_PATH);
 383
 384        /* Check that we have a git documentation directory. */
 385        if (stat(mkpath("%s/git.html", html_path), &st)
 386            || !S_ISREG(st.st_mode))
 387                die("'%s': not a documentation directory.", html_path);
 388
 389        strbuf_init(page_path, 0);
 390        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 391}
 392
 393/*
 394 * If open_html is not defined in a platform-specific way (see for
 395 * example compat/mingw.h), we use the script web--browse to display
 396 * HTML.
 397 */
 398#ifndef open_html
 399static void open_html(const char *path)
 400{
 401        execl_git_cmd("web--browse", "-c", "help.browser", path, NULL);
 402}
 403#endif
 404
 405static void show_html_page(const char *git_cmd)
 406{
 407        const char *page = cmd_to_page(git_cmd);
 408        struct strbuf page_path; /* it leaks but we exec bellow */
 409
 410        get_html_page_path(&page_path, page);
 411
 412        open_html(page_path.buf);
 413}
 414
 415int cmd_help(int argc, const char **argv, const char *prefix)
 416{
 417        int nongit;
 418        const char *alias;
 419        enum help_format parsed_help_format;
 420        load_command_list("git-", &main_cmds, &other_cmds);
 421
 422        argc = parse_options(argc, argv, prefix, builtin_help_options,
 423                        builtin_help_usage, 0);
 424        parsed_help_format = help_format;
 425
 426        if (show_all) {
 427                printf("usage: %s\n\n", git_usage_string);
 428                list_commands("git commands", &main_cmds, &other_cmds);
 429                printf("%s\n", git_more_info_string);
 430                return 0;
 431        }
 432
 433        if (!argv[0]) {
 434                printf("usage: %s\n\n", git_usage_string);
 435                list_common_cmds_help();
 436                printf("\n%s\n", git_more_info_string);
 437                return 0;
 438        }
 439
 440        setup_git_directory_gently(&nongit);
 441        git_config(git_help_config, NULL);
 442
 443        if (parsed_help_format != HELP_FORMAT_NONE)
 444                help_format = parsed_help_format;
 445
 446        alias = alias_lookup(argv[0]);
 447        if (alias && !is_git_command(argv[0])) {
 448                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 449                return 0;
 450        }
 451
 452        switch (help_format) {
 453        case HELP_FORMAT_NONE:
 454        case HELP_FORMAT_MAN:
 455                show_man_page(argv[0]);
 456                break;
 457        case HELP_FORMAT_INFO:
 458                show_info_page(argv[0]);
 459                break;
 460        case HELP_FORMAT_WEB:
 461                show_html_page(argv[0]);
 462                break;
 463        }
 464
 465        return 0;
 466}