Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit remote-bzr: reorganize the way 'wanted' works (e56660a)
   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 "parse-options.h"
  10#include "run-command.h"
  11#include "column.h"
  12#include "help.h"
  13
  14#ifndef DEFAULT_HELP_FORMAT
  15#define DEFAULT_HELP_FORMAT "man"
  16#endif
  17
  18static struct man_viewer_list {
  19        struct man_viewer_list *next;
  20        char name[FLEX_ARRAY];
  21} *man_viewer_list;
  22
  23static struct man_viewer_info_list {
  24        struct man_viewer_info_list *next;
  25        const char *info;
  26        char name[FLEX_ARRAY];
  27} *man_viewer_info_list;
  28
  29enum help_format {
  30        HELP_FORMAT_NONE,
  31        HELP_FORMAT_MAN,
  32        HELP_FORMAT_INFO,
  33        HELP_FORMAT_WEB
  34};
  35
  36static const char *html_path;
  37
  38static int show_all = 0;
  39static int show_guides = 0;
  40static unsigned int colopts;
  41static enum help_format help_format = HELP_FORMAT_NONE;
  42static struct option builtin_help_options[] = {
  43        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  44        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  45        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  46        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  47                        HELP_FORMAT_WEB),
  48        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  49                        HELP_FORMAT_INFO),
  50        OPT_END(),
  51};
  52
  53static const char * const builtin_help_usage[] = {
  54        N_("git help [--all] [--guides] [--man|--web|--info] [command]"),
  55        NULL
  56};
  57
  58static enum help_format parse_help_format(const char *format)
  59{
  60        if (!strcmp(format, "man"))
  61                return HELP_FORMAT_MAN;
  62        if (!strcmp(format, "info"))
  63                return HELP_FORMAT_INFO;
  64        if (!strcmp(format, "web") || !strcmp(format, "html"))
  65                return HELP_FORMAT_WEB;
  66        die(_("unrecognized help format '%s'"), format);
  67}
  68
  69static const char *get_man_viewer_info(const char *name)
  70{
  71        struct man_viewer_info_list *viewer;
  72
  73        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  74        {
  75                if (!strcasecmp(name, viewer->name))
  76                        return viewer->info;
  77        }
  78        return NULL;
  79}
  80
  81static int check_emacsclient_version(void)
  82{
  83        struct strbuf buffer = STRBUF_INIT;
  84        struct child_process ec_process;
  85        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  86        int version;
  87
  88        /* emacsclient prints its version number on stderr */
  89        memset(&ec_process, 0, sizeof(ec_process));
  90        ec_process.argv = argv_ec;
  91        ec_process.err = -1;
  92        ec_process.stdout_to_stderr = 1;
  93        if (start_command(&ec_process))
  94                return error(_("Failed to start emacsclient."));
  95
  96        strbuf_read(&buffer, ec_process.err, 20);
  97        close(ec_process.err);
  98
  99        /*
 100         * Don't bother checking return value, because "emacsclient --version"
 101         * seems to always exits with code 1.
 102         */
 103        finish_command(&ec_process);
 104
 105        if (prefixcmp(buffer.buf, "emacsclient")) {
 106                strbuf_release(&buffer);
 107                return error(_("Failed to parse emacsclient version."));
 108        }
 109
 110        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 111        version = atoi(buffer.buf);
 112
 113        if (version < 22) {
 114                strbuf_release(&buffer);
 115                return error(_("emacsclient version '%d' too old (< 22)."),
 116                        version);
 117        }
 118
 119        strbuf_release(&buffer);
 120        return 0;
 121}
 122
 123static void exec_woman_emacs(const char *path, const char *page)
 124{
 125        if (!check_emacsclient_version()) {
 126                /* This works only with emacsclient version >= 22. */
 127                struct strbuf man_page = STRBUF_INIT;
 128
 129                if (!path)
 130                        path = "emacsclient";
 131                strbuf_addf(&man_page, "(woman \"%s\")", page);
 132                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 133                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 134        }
 135}
 136
 137static void exec_man_konqueror(const char *path, const char *page)
 138{
 139        const char *display = getenv("DISPLAY");
 140        if (display && *display) {
 141                struct strbuf man_page = STRBUF_INIT;
 142                const char *filename = "kfmclient";
 143
 144                /* It's simpler to launch konqueror using kfmclient. */
 145                if (path) {
 146                        const char *file = strrchr(path, '/');
 147                        if (file && !strcmp(file + 1, "konqueror")) {
 148                                char *new = xstrdup(path);
 149                                char *dest = strrchr(new, '/');
 150
 151                                /* strlen("konqueror") == strlen("kfmclient") */
 152                                strcpy(dest + 1, "kfmclient");
 153                                path = new;
 154                        }
 155                        if (file)
 156                                filename = file;
 157                } else
 158                        path = "kfmclient";
 159                strbuf_addf(&man_page, "man:%s(1)", page);
 160                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 161                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 162        }
 163}
 164
 165static void exec_man_man(const char *path, const char *page)
 166{
 167        if (!path)
 168                path = "man";
 169        execlp(path, "man", page, (char *)NULL);
 170        warning(_("failed to exec '%s': %s"), path, strerror(errno));
 171}
 172
 173static void exec_man_cmd(const char *cmd, const char *page)
 174{
 175        struct strbuf shell_cmd = STRBUF_INIT;
 176        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 177        execl("/bin/sh", "sh", "-c", shell_cmd.buf, (char *)NULL);
 178        warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
 179}
 180
 181static void add_man_viewer(const char *name)
 182{
 183        struct man_viewer_list **p = &man_viewer_list;
 184        size_t len = strlen(name);
 185
 186        while (*p)
 187                p = &((*p)->next);
 188        *p = xcalloc(1, (sizeof(**p) + len + 1));
 189        strncpy((*p)->name, name, len);
 190}
 191
 192static int supported_man_viewer(const char *name, size_t len)
 193{
 194        return (!strncasecmp("man", name, len) ||
 195                !strncasecmp("woman", name, len) ||
 196                !strncasecmp("konqueror", name, len));
 197}
 198
 199static void do_add_man_viewer_info(const char *name,
 200                                   size_t len,
 201                                   const char *value)
 202{
 203        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 204
 205        strncpy(new->name, name, len);
 206        new->info = xstrdup(value);
 207        new->next = man_viewer_info_list;
 208        man_viewer_info_list = new;
 209}
 210
 211static int add_man_viewer_path(const char *name,
 212                               size_t len,
 213                               const char *value)
 214{
 215        if (supported_man_viewer(name, len))
 216                do_add_man_viewer_info(name, len, value);
 217        else
 218                warning(_("'%s': path for unsupported man viewer.\n"
 219                          "Please consider using 'man.<tool>.cmd' instead."),
 220                        name);
 221
 222        return 0;
 223}
 224
 225static int add_man_viewer_cmd(const char *name,
 226                              size_t len,
 227                              const char *value)
 228{
 229        if (supported_man_viewer(name, len))
 230                warning(_("'%s': cmd for supported man viewer.\n"
 231                          "Please consider using 'man.<tool>.path' instead."),
 232                        name);
 233        else
 234                do_add_man_viewer_info(name, len, value);
 235
 236        return 0;
 237}
 238
 239static int add_man_viewer_info(const char *var, const char *value)
 240{
 241        const char *name, *subkey;
 242        int namelen;
 243
 244        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 245                return 0;
 246
 247        if (!strcmp(subkey, "path")) {
 248                if (!value)
 249                        return config_error_nonbool(var);
 250                return add_man_viewer_path(name, namelen, value);
 251        }
 252        if (!strcmp(subkey, "cmd")) {
 253                if (!value)
 254                        return config_error_nonbool(var);
 255                return add_man_viewer_cmd(name, namelen, value);
 256        }
 257
 258        return 0;
 259}
 260
 261static int git_help_config(const char *var, const char *value, void *cb)
 262{
 263        if (!prefixcmp(var, "column."))
 264                return git_column_config(var, value, "help", &colopts);
 265        if (!strcmp(var, "help.format")) {
 266                if (!value)
 267                        return config_error_nonbool(var);
 268                help_format = parse_help_format(value);
 269                return 0;
 270        }
 271        if (!strcmp(var, "help.htmlpath")) {
 272                if (!value)
 273                        return config_error_nonbool(var);
 274                html_path = xstrdup(value);
 275                return 0;
 276        }
 277        if (!strcmp(var, "man.viewer")) {
 278                if (!value)
 279                        return config_error_nonbool(var);
 280                add_man_viewer(value);
 281                return 0;
 282        }
 283        if (!prefixcmp(var, "man."))
 284                return add_man_viewer_info(var, value);
 285
 286        return git_default_config(var, value, cb);
 287}
 288
 289static struct cmdnames main_cmds, other_cmds;
 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, (char *)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        if (!html_path)
 383                html_path = system_path(GIT_HTML_PATH);
 384
 385        /* Check that we have a git documentation directory. */
 386        if (!strstr(html_path, "://")) {
 387                if (stat(mkpath("%s/git.html", html_path), &st)
 388                    || !S_ISREG(st.st_mode))
 389                        die("'%s': not a documentation directory.", html_path);
 390        }
 391
 392        strbuf_init(page_path, 0);
 393        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 394}
 395
 396/*
 397 * If open_html is not defined in a platform-specific way (see for
 398 * example compat/mingw.h), we use the script web--browse to display
 399 * HTML.
 400 */
 401#ifndef open_html
 402static void open_html(const char *path)
 403{
 404        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 405}
 406#endif
 407
 408static void show_html_page(const char *git_cmd)
 409{
 410        const char *page = cmd_to_page(git_cmd);
 411        struct strbuf page_path; /* it leaks but we exec bellow */
 412
 413        get_html_page_path(&page_path, page);
 414
 415        open_html(page_path.buf);
 416}
 417
 418static struct {
 419        const char *name;
 420        const char *help;
 421} common_guides[] = {
 422        { "attributes", N_("Defining attributes per path") },
 423        { "glossary", N_("A Git glossary") },
 424        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 425        { "modules", N_("Defining submodule properties") },
 426        { "revisions", N_("Specifying revisions and ranges for Git") },
 427        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 428        { "workflows", N_("An overview of recommended workflows with Git") },
 429};
 430
 431static void list_common_guides_help(void)
 432{
 433        int i, longest = 0;
 434
 435        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 436                if (longest < strlen(common_guides[i].name))
 437                        longest = strlen(common_guides[i].name);
 438        }
 439
 440        puts(_("The common Git guides are:\n"));
 441        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 442                printf("   %s   ", common_guides[i].name);
 443                mput_char(' ', longest - strlen(common_guides[i].name));
 444                puts(_(common_guides[i].help));
 445        }
 446        putchar('\n');
 447}
 448
 449int cmd_help(int argc, const char **argv, const char *prefix)
 450{
 451        int nongit;
 452        const char *alias;
 453        enum help_format parsed_help_format;
 454        load_command_list("git-", &main_cmds, &other_cmds);
 455
 456        argc = parse_options(argc, argv, prefix, builtin_help_options,
 457                        builtin_help_usage, 0);
 458        parsed_help_format = help_format;
 459
 460        if (show_all) {
 461                git_config(git_help_config, NULL);
 462                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 463                list_commands(colopts, &main_cmds, &other_cmds);
 464        }
 465
 466        if (show_guides)
 467                list_common_guides_help();
 468
 469        if (show_all || show_guides) {
 470                printf("%s\n", _(git_more_info_string));
 471                /*
 472                * We're done. Ignore any remaining args
 473                */
 474                return 0;
 475        }
 476
 477        if (!argv[0]) {
 478                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 479                list_common_cmds_help();
 480                printf("\n%s\n", _(git_more_info_string));
 481                return 0;
 482        }
 483
 484        setup_git_directory_gently(&nongit);
 485        git_config(git_help_config, NULL);
 486
 487        if (parsed_help_format != HELP_FORMAT_NONE)
 488                help_format = parsed_help_format;
 489        if (help_format == HELP_FORMAT_NONE)
 490                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 491
 492        alias = alias_lookup(argv[0]);
 493        if (alias && !is_git_command(argv[0])) {
 494                printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
 495                return 0;
 496        }
 497
 498        switch (help_format) {
 499        case HELP_FORMAT_NONE:
 500        case HELP_FORMAT_MAN:
 501                show_man_page(argv[0]);
 502                break;
 503        case HELP_FORMAT_INFO:
 504                show_info_page(argv[0]);
 505                break;
 506        case HELP_FORMAT_WEB:
 507                show_html_page(argv[0]);
 508                break;
 509        }
 510
 511        return 0;
 512}