Andrew's git / gitweb.git / builtin/help.c
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builtin / help.con commit Merge branch 'nd/gc-lock-against-each-other' (05584b2)
   1/*
   2 * Builtin help command
   3 */
   4#include "cache.h"
   5#include "builtin.h"
   6#include "exec_cmd.h"
   7#include "parse-options.h"
   8#include "run-command.h"
   9#include "column.h"
  10#include "help.h"
  11
  12#ifndef DEFAULT_HELP_FORMAT
  13#define DEFAULT_HELP_FORMAT "man"
  14#endif
  15
  16static struct man_viewer_list {
  17        struct man_viewer_list *next;
  18        char name[FLEX_ARRAY];
  19} *man_viewer_list;
  20
  21static struct man_viewer_info_list {
  22        struct man_viewer_info_list *next;
  23        const char *info;
  24        char name[FLEX_ARRAY];
  25} *man_viewer_info_list;
  26
  27enum help_format {
  28        HELP_FORMAT_NONE,
  29        HELP_FORMAT_MAN,
  30        HELP_FORMAT_INFO,
  31        HELP_FORMAT_WEB
  32};
  33
  34static const char *html_path;
  35
  36static int show_all = 0;
  37static int show_guides = 0;
  38static unsigned int colopts;
  39static enum help_format help_format = HELP_FORMAT_NONE;
  40static struct option builtin_help_options[] = {
  41        OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
  42        OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
  43        OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
  44        OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
  45                        HELP_FORMAT_WEB),
  46        OPT_SET_INT('i', "info", &help_format, N_("show info page"),
  47                        HELP_FORMAT_INFO),
  48        OPT_END(),
  49};
  50
  51static const char * const builtin_help_usage[] = {
  52        N_("git help [--all] [--guides] [--man|--web|--info] [command]"),
  53        NULL
  54};
  55
  56static enum help_format parse_help_format(const char *format)
  57{
  58        if (!strcmp(format, "man"))
  59                return HELP_FORMAT_MAN;
  60        if (!strcmp(format, "info"))
  61                return HELP_FORMAT_INFO;
  62        if (!strcmp(format, "web") || !strcmp(format, "html"))
  63                return HELP_FORMAT_WEB;
  64        die(_("unrecognized help format '%s'"), format);
  65}
  66
  67static const char *get_man_viewer_info(const char *name)
  68{
  69        struct man_viewer_info_list *viewer;
  70
  71        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  72        {
  73                if (!strcasecmp(name, viewer->name))
  74                        return viewer->info;
  75        }
  76        return NULL;
  77}
  78
  79static int check_emacsclient_version(void)
  80{
  81        struct strbuf buffer = STRBUF_INIT;
  82        struct child_process ec_process;
  83        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  84        int version;
  85
  86        /* emacsclient prints its version number on stderr */
  87        memset(&ec_process, 0, sizeof(ec_process));
  88        ec_process.argv = argv_ec;
  89        ec_process.err = -1;
  90        ec_process.stdout_to_stderr = 1;
  91        if (start_command(&ec_process))
  92                return error(_("Failed to start emacsclient."));
  93
  94        strbuf_read(&buffer, ec_process.err, 20);
  95        close(ec_process.err);
  96
  97        /*
  98         * Don't bother checking return value, because "emacsclient --version"
  99         * seems to always exits with code 1.
 100         */
 101        finish_command(&ec_process);
 102
 103        if (prefixcmp(buffer.buf, "emacsclient")) {
 104                strbuf_release(&buffer);
 105                return error(_("Failed to parse emacsclient version."));
 106        }
 107
 108        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 109        version = atoi(buffer.buf);
 110
 111        if (version < 22) {
 112                strbuf_release(&buffer);
 113                return error(_("emacsclient version '%d' too old (< 22)."),
 114                        version);
 115        }
 116
 117        strbuf_release(&buffer);
 118        return 0;
 119}
 120
 121static void exec_woman_emacs(const char *path, const char *page)
 122{
 123        if (!check_emacsclient_version()) {
 124                /* This works only with emacsclient version >= 22. */
 125                struct strbuf man_page = STRBUF_INIT;
 126
 127                if (!path)
 128                        path = "emacsclient";
 129                strbuf_addf(&man_page, "(woman \"%s\")", page);
 130                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 131                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 132        }
 133}
 134
 135static void exec_man_konqueror(const char *path, const char *page)
 136{
 137        const char *display = getenv("DISPLAY");
 138        if (display && *display) {
 139                struct strbuf man_page = STRBUF_INIT;
 140                const char *filename = "kfmclient";
 141
 142                /* It's simpler to launch konqueror using kfmclient. */
 143                if (path) {
 144                        const char *file = strrchr(path, '/');
 145                        if (file && !strcmp(file + 1, "konqueror")) {
 146                                char *new = xstrdup(path);
 147                                char *dest = strrchr(new, '/');
 148
 149                                /* strlen("konqueror") == strlen("kfmclient") */
 150                                strcpy(dest + 1, "kfmclient");
 151                                path = new;
 152                        }
 153                        if (file)
 154                                filename = file;
 155                } else
 156                        path = "kfmclient";
 157                strbuf_addf(&man_page, "man:%s(1)", page);
 158                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 159                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 160        }
 161}
 162
 163static void exec_man_man(const char *path, const char *page)
 164{
 165        if (!path)
 166                path = "man";
 167        execlp(path, "man", page, (char *)NULL);
 168        warning(_("failed to exec '%s': %s"), path, strerror(errno));
 169}
 170
 171static void exec_man_cmd(const char *cmd, const char *page)
 172{
 173        struct strbuf shell_cmd = STRBUF_INIT;
 174        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 175        execl("/bin/sh", "sh", "-c", shell_cmd.buf, (char *)NULL);
 176        warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
 177}
 178
 179static void add_man_viewer(const char *name)
 180{
 181        struct man_viewer_list **p = &man_viewer_list;
 182        size_t len = strlen(name);
 183
 184        while (*p)
 185                p = &((*p)->next);
 186        *p = xcalloc(1, (sizeof(**p) + len + 1));
 187        strncpy((*p)->name, name, len);
 188}
 189
 190static int supported_man_viewer(const char *name, size_t len)
 191{
 192        return (!strncasecmp("man", name, len) ||
 193                !strncasecmp("woman", name, len) ||
 194                !strncasecmp("konqueror", name, len));
 195}
 196
 197static void do_add_man_viewer_info(const char *name,
 198                                   size_t len,
 199                                   const char *value)
 200{
 201        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 202
 203        strncpy(new->name, name, len);
 204        new->info = xstrdup(value);
 205        new->next = man_viewer_info_list;
 206        man_viewer_info_list = new;
 207}
 208
 209static int add_man_viewer_path(const char *name,
 210                               size_t len,
 211                               const char *value)
 212{
 213        if (supported_man_viewer(name, len))
 214                do_add_man_viewer_info(name, len, value);
 215        else
 216                warning(_("'%s': path for unsupported man viewer.\n"
 217                          "Please consider using 'man.<tool>.cmd' instead."),
 218                        name);
 219
 220        return 0;
 221}
 222
 223static int add_man_viewer_cmd(const char *name,
 224                              size_t len,
 225                              const char *value)
 226{
 227        if (supported_man_viewer(name, len))
 228                warning(_("'%s': cmd for supported man viewer.\n"
 229                          "Please consider using 'man.<tool>.path' instead."),
 230                        name);
 231        else
 232                do_add_man_viewer_info(name, len, value);
 233
 234        return 0;
 235}
 236
 237static int add_man_viewer_info(const char *var, const char *value)
 238{
 239        const char *name, *subkey;
 240        int namelen;
 241
 242        if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
 243                return 0;
 244
 245        if (!strcmp(subkey, "path")) {
 246                if (!value)
 247                        return config_error_nonbool(var);
 248                return add_man_viewer_path(name, namelen, value);
 249        }
 250        if (!strcmp(subkey, "cmd")) {
 251                if (!value)
 252                        return config_error_nonbool(var);
 253                return add_man_viewer_cmd(name, namelen, value);
 254        }
 255
 256        return 0;
 257}
 258
 259static int git_help_config(const char *var, const char *value, void *cb)
 260{
 261        if (!prefixcmp(var, "column."))
 262                return git_column_config(var, value, "help", &colopts);
 263        if (!strcmp(var, "help.format")) {
 264                if (!value)
 265                        return config_error_nonbool(var);
 266                help_format = parse_help_format(value);
 267                return 0;
 268        }
 269        if (!strcmp(var, "help.htmlpath")) {
 270                if (!value)
 271                        return config_error_nonbool(var);
 272                html_path = xstrdup(value);
 273                return 0;
 274        }
 275        if (!strcmp(var, "man.viewer")) {
 276                if (!value)
 277                        return config_error_nonbool(var);
 278                add_man_viewer(value);
 279                return 0;
 280        }
 281        if (!prefixcmp(var, "man."))
 282                return add_man_viewer_info(var, value);
 283
 284        return git_default_config(var, value, cb);
 285}
 286
 287static struct cmdnames main_cmds, other_cmds;
 288
 289static int is_git_command(const char *s)
 290{
 291        return is_in_cmdlist(&main_cmds, s) ||
 292                is_in_cmdlist(&other_cmds, s);
 293}
 294
 295static const char *prepend(const char *prefix, const char *cmd)
 296{
 297        size_t pre_len = strlen(prefix);
 298        size_t cmd_len = strlen(cmd);
 299        char *p = xmalloc(pre_len + cmd_len + 1);
 300        memcpy(p, prefix, pre_len);
 301        strcpy(p + pre_len, cmd);
 302        return p;
 303}
 304
 305static const char *cmd_to_page(const char *git_cmd)
 306{
 307        if (!git_cmd)
 308                return "git";
 309        else if (!prefixcmp(git_cmd, "git"))
 310                return git_cmd;
 311        else if (is_git_command(git_cmd))
 312                return prepend("git-", git_cmd);
 313        else
 314                return prepend("git", git_cmd);
 315}
 316
 317static void setup_man_path(void)
 318{
 319        struct strbuf new_path = STRBUF_INIT;
 320        const char *old_path = getenv("MANPATH");
 321
 322        /* We should always put ':' after our path. If there is no
 323         * old_path, the ':' at the end will let 'man' to try
 324         * system-wide paths after ours to find the manual page. If
 325         * there is old_path, we need ':' as delimiter. */
 326        strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
 327        strbuf_addch(&new_path, ':');
 328        if (old_path)
 329                strbuf_addstr(&new_path, old_path);
 330
 331        setenv("MANPATH", new_path.buf, 1);
 332
 333        strbuf_release(&new_path);
 334}
 335
 336static void exec_viewer(const char *name, const char *page)
 337{
 338        const char *info = get_man_viewer_info(name);
 339
 340        if (!strcasecmp(name, "man"))
 341                exec_man_man(info, page);
 342        else if (!strcasecmp(name, "woman"))
 343                exec_woman_emacs(info, page);
 344        else if (!strcasecmp(name, "konqueror"))
 345                exec_man_konqueror(info, page);
 346        else if (info)
 347                exec_man_cmd(info, page);
 348        else
 349                warning(_("'%s': unknown man viewer."), name);
 350}
 351
 352static void show_man_page(const char *git_cmd)
 353{
 354        struct man_viewer_list *viewer;
 355        const char *page = cmd_to_page(git_cmd);
 356        const char *fallback = getenv("GIT_MAN_VIEWER");
 357
 358        setup_man_path();
 359        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 360        {
 361                exec_viewer(viewer->name, page); /* will return when unable */
 362        }
 363        if (fallback)
 364                exec_viewer(fallback, page);
 365        exec_viewer("man", page);
 366        die(_("no man viewer handled the request"));
 367}
 368
 369static void show_info_page(const char *git_cmd)
 370{
 371        const char *page = cmd_to_page(git_cmd);
 372        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 373        execlp("info", "info", "gitman", page, (char *)NULL);
 374        die(_("no info viewer handled the request"));
 375}
 376
 377static void get_html_page_path(struct strbuf *page_path, const char *page)
 378{
 379        struct stat st;
 380        if (!html_path)
 381                html_path = system_path(GIT_HTML_PATH);
 382
 383        /* Check that we have a git documentation directory. */
 384        if (!strstr(html_path, "://")) {
 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
 390        strbuf_init(page_path, 0);
 391        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 392}
 393
 394/*
 395 * If open_html is not defined in a platform-specific way (see for
 396 * example compat/mingw.h), we use the script web--browse to display
 397 * HTML.
 398 */
 399#ifndef open_html
 400static void open_html(const char *path)
 401{
 402        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 403}
 404#endif
 405
 406static void show_html_page(const char *git_cmd)
 407{
 408        const char *page = cmd_to_page(git_cmd);
 409        struct strbuf page_path; /* it leaks but we exec bellow */
 410
 411        get_html_page_path(&page_path, page);
 412
 413        open_html(page_path.buf);
 414}
 415
 416static struct {
 417        const char *name;
 418        const char *help;
 419} common_guides[] = {
 420        { "attributes", N_("Defining attributes per path") },
 421        { "glossary", N_("A Git glossary") },
 422        { "ignore", N_("Specifies intentionally untracked files to ignore") },
 423        { "modules", N_("Defining submodule properties") },
 424        { "revisions", N_("Specifying revisions and ranges for Git") },
 425        { "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
 426        { "workflows", N_("An overview of recommended workflows with Git") },
 427};
 428
 429static void list_common_guides_help(void)
 430{
 431        int i, longest = 0;
 432
 433        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 434                if (longest < strlen(common_guides[i].name))
 435                        longest = strlen(common_guides[i].name);
 436        }
 437
 438        puts(_("The common Git guides are:\n"));
 439        for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
 440                printf("   %s   ", common_guides[i].name);
 441                mput_char(' ', longest - strlen(common_guides[i].name));
 442                puts(_(common_guides[i].help));
 443        }
 444        putchar('\n');
 445}
 446
 447int cmd_help(int argc, const char **argv, const char *prefix)
 448{
 449        int nongit;
 450        const char *alias;
 451        enum help_format parsed_help_format;
 452        load_command_list("git-", &main_cmds, &other_cmds);
 453
 454        argc = parse_options(argc, argv, prefix, builtin_help_options,
 455                        builtin_help_usage, 0);
 456        parsed_help_format = help_format;
 457
 458        if (show_all) {
 459                git_config(git_help_config, NULL);
 460                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 461                list_commands(colopts, &main_cmds, &other_cmds);
 462        }
 463
 464        if (show_guides)
 465                list_common_guides_help();
 466
 467        if (show_all || show_guides) {
 468                printf("%s\n", _(git_more_info_string));
 469                /*
 470                * We're done. Ignore any remaining args
 471                */
 472                return 0;
 473        }
 474
 475        if (!argv[0]) {
 476                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 477                list_common_cmds_help();
 478                printf("\n%s\n", _(git_more_info_string));
 479                return 0;
 480        }
 481
 482        setup_git_directory_gently(&nongit);
 483        git_config(git_help_config, NULL);
 484
 485        if (parsed_help_format != HELP_FORMAT_NONE)
 486                help_format = parsed_help_format;
 487        if (help_format == HELP_FORMAT_NONE)
 488                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 489
 490        alias = alias_lookup(argv[0]);
 491        if (alias && !is_git_command(argv[0])) {
 492                printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
 493                return 0;
 494        }
 495
 496        switch (help_format) {
 497        case HELP_FORMAT_NONE:
 498        case HELP_FORMAT_MAN:
 499                show_man_page(argv[0]);
 500                break;
 501        case HELP_FORMAT_INFO:
 502                show_info_page(argv[0]);
 503                break;
 504        case HELP_FORMAT_WEB:
 505                show_html_page(argv[0]);
 506                break;
 507        }
 508
 509        return 0;
 510}