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 "column.h"
  13#include "help.h"
  14
  15#ifndef DEFAULT_HELP_FORMAT
  16#define DEFAULT_HELP_FORMAT "man"
  17#endif
  18
  19static struct man_viewer_list {
  20        struct man_viewer_list *next;
  21        char name[FLEX_ARRAY];
  22} *man_viewer_list;
  23
  24static struct man_viewer_info_list {
  25        struct man_viewer_info_list *next;
  26        const char *info;
  27        char name[FLEX_ARRAY];
  28} *man_viewer_info_list;
  29
  30enum help_format {
  31        HELP_FORMAT_NONE,
  32        HELP_FORMAT_MAN,
  33        HELP_FORMAT_INFO,
  34        HELP_FORMAT_WEB
  35};
  36
  37static int show_all = 0;
  38static unsigned int colopts;
  39static enum help_format help_format = HELP_FORMAT_NONE;
  40static struct option builtin_help_options[] = {
  41        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  42        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  43        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  44                        HELP_FORMAT_WEB),
  45        OPT_SET_INT('i', "info", &help_format, "show info page",
  46                        HELP_FORMAT_INFO),
  47        OPT_END(),
  48};
  49
  50static const char * const builtin_help_usage[] = {
  51        "git help [--all] [--man|--web|--info] [command]",
  52        NULL
  53};
  54
  55static enum help_format parse_help_format(const char *format)
  56{
  57        if (!strcmp(format, "man"))
  58                return HELP_FORMAT_MAN;
  59        if (!strcmp(format, "info"))
  60                return HELP_FORMAT_INFO;
  61        if (!strcmp(format, "web") || !strcmp(format, "html"))
  62                return HELP_FORMAT_WEB;
  63        die(_("unrecognized help format '%s'"), format);
  64}
  65
  66static const char *get_man_viewer_info(const char *name)
  67{
  68        struct man_viewer_info_list *viewer;
  69
  70        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  71        {
  72                if (!strcasecmp(name, viewer->name))
  73                        return viewer->info;
  74        }
  75        return NULL;
  76}
  77
  78static int check_emacsclient_version(void)
  79{
  80        struct strbuf buffer = STRBUF_INIT;
  81        struct child_process ec_process;
  82        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  83        int version;
  84
  85        /* emacsclient prints its version number on stderr */
  86        memset(&ec_process, 0, sizeof(ec_process));
  87        ec_process.argv = argv_ec;
  88        ec_process.err = -1;
  89        ec_process.stdout_to_stderr = 1;
  90        if (start_command(&ec_process))
  91                return error(_("Failed to start emacsclient."));
  92
  93        strbuf_read(&buffer, ec_process.err, 20);
  94        close(ec_process.err);
  95
  96        /*
  97         * Don't bother checking return value, because "emacsclient --version"
  98         * seems to always exits with code 1.
  99         */
 100        finish_command(&ec_process);
 101
 102        if (prefixcmp(buffer.buf, "emacsclient")) {
 103                strbuf_release(&buffer);
 104                return error(_("Failed to parse emacsclient version."));
 105        }
 106
 107        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 108        version = atoi(buffer.buf);
 109
 110        if (version < 22) {
 111                strbuf_release(&buffer);
 112                return error(_("emacsclient version '%d' too old (< 22)."),
 113                        version);
 114        }
 115
 116        strbuf_release(&buffer);
 117        return 0;
 118}
 119
 120static void exec_woman_emacs(const char *path, const char *page)
 121{
 122        if (!check_emacsclient_version()) {
 123                /* This works only with emacsclient version >= 22. */
 124                struct strbuf man_page = STRBUF_INIT;
 125
 126                if (!path)
 127                        path = "emacsclient";
 128                strbuf_addf(&man_page, "(woman \"%s\")", page);
 129                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 130                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 131        }
 132}
 133
 134static void exec_man_konqueror(const char *path, const char *page)
 135{
 136        const char *display = getenv("DISPLAY");
 137        if (display && *display) {
 138                struct strbuf man_page = STRBUF_INIT;
 139                const char *filename = "kfmclient";
 140
 141                /* It's simpler to launch konqueror using kfmclient. */
 142                if (path) {
 143                        const char *file = strrchr(path, '/');
 144                        if (file && !strcmp(file + 1, "konqueror")) {
 145                                char *new = xstrdup(path);
 146                                char *dest = strrchr(new, '/');
 147
 148                                /* strlen("konqueror") == strlen("kfmclient") */
 149                                strcpy(dest + 1, "kfmclient");
 150                                path = new;
 151                        }
 152                        if (file)
 153                                filename = file;
 154                } else
 155                        path = "kfmclient";
 156                strbuf_addf(&man_page, "man:%s(1)", page);
 157                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 158                warning(_("failed to exec '%s': %s"), path, strerror(errno));
 159        }
 160}
 161
 162static void exec_man_man(const char *path, const char *page)
 163{
 164        if (!path)
 165                path = "man";
 166        execlp(path, "man", page, (char *)NULL);
 167        warning(_("failed to exec '%s': %s"), path, strerror(errno));
 168}
 169
 170static void exec_man_cmd(const char *cmd, const char *page)
 171{
 172        struct strbuf shell_cmd = STRBUF_INIT;
 173        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 174        execl("/bin/sh", "sh", "-c", shell_cmd.buf, (char *)NULL);
 175        warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
 176}
 177
 178static void add_man_viewer(const char *name)
 179{
 180        struct man_viewer_list **p = &man_viewer_list;
 181        size_t len = strlen(name);
 182
 183        while (*p)
 184                p = &((*p)->next);
 185        *p = xcalloc(1, (sizeof(**p) + len + 1));
 186        strncpy((*p)->name, name, len);
 187}
 188
 189static int supported_man_viewer(const char *name, size_t len)
 190{
 191        return (!strncasecmp("man", name, len) ||
 192                !strncasecmp("woman", name, len) ||
 193                !strncasecmp("konqueror", name, len));
 194}
 195
 196static void do_add_man_viewer_info(const char *name,
 197                                   size_t len,
 198                                   const char *value)
 199{
 200        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 201
 202        strncpy(new->name, name, len);
 203        new->info = xstrdup(value);
 204        new->next = man_viewer_info_list;
 205        man_viewer_info_list = new;
 206}
 207
 208static int add_man_viewer_path(const char *name,
 209                               size_t len,
 210                               const char *value)
 211{
 212        if (supported_man_viewer(name, len))
 213                do_add_man_viewer_info(name, len, value);
 214        else
 215                warning(_("'%s': path for unsupported man viewer.\n"
 216                          "Please consider using 'man.<tool>.cmd' instead."),
 217                        name);
 218
 219        return 0;
 220}
 221
 222static int add_man_viewer_cmd(const char *name,
 223                              size_t len,
 224                              const char *value)
 225{
 226        if (supported_man_viewer(name, len))
 227                warning(_("'%s': cmd for supported man viewer.\n"
 228                          "Please consider using 'man.<tool>.path' instead."),
 229                        name);
 230        else
 231                do_add_man_viewer_info(name, len, value);
 232
 233        return 0;
 234}
 235
 236static int add_man_viewer_info(const char *var, const char *value)
 237{
 238        const char *name = var + 4;
 239        const char *subkey = strrchr(name, '.');
 240
 241        if (!subkey)
 242                return 0;
 243
 244        if (!strcmp(subkey, ".path")) {
 245                if (!value)
 246                        return config_error_nonbool(var);
 247                return add_man_viewer_path(name, subkey - name, value);
 248        }
 249        if (!strcmp(subkey, ".cmd")) {
 250                if (!value)
 251                        return config_error_nonbool(var);
 252                return add_man_viewer_cmd(name, subkey - name, value);
 253        }
 254
 255        return 0;
 256}
 257
 258static int git_help_config(const char *var, const char *value, void *cb)
 259{
 260        if (!prefixcmp(var, "column."))
 261                return git_column_config(var, value, "help", &colopts);
 262        if (!strcmp(var, "help.format")) {
 263                if (!value)
 264                        return config_error_nonbool(var);
 265                help_format = parse_help_format(value);
 266                return 0;
 267        }
 268        if (!strcmp(var, "man.viewer")) {
 269                if (!value)
 270                        return config_error_nonbool(var);
 271                add_man_viewer(value);
 272                return 0;
 273        }
 274        if (!prefixcmp(var, "man."))
 275                return add_man_viewer_info(var, value);
 276
 277        return git_default_config(var, value, cb);
 278}
 279
 280static struct cmdnames main_cmds, other_cmds;
 281
 282void list_common_cmds_help(void)
 283{
 284        int i, longest = 0;
 285
 286        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 287                if (longest < strlen(common_cmds[i].name))
 288                        longest = strlen(common_cmds[i].name);
 289        }
 290
 291        puts(_("The most commonly used git commands are:"));
 292        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 293                printf("   %s   ", common_cmds[i].name);
 294                mput_char(' ', longest - strlen(common_cmds[i].name));
 295                puts(_(common_cmds[i].help));
 296        }
 297}
 298
 299static int is_git_command(const char *s)
 300{
 301        return is_in_cmdlist(&main_cmds, s) ||
 302                is_in_cmdlist(&other_cmds, s);
 303}
 304
 305static const char *prepend(const char *prefix, const char *cmd)
 306{
 307        size_t pre_len = strlen(prefix);
 308        size_t cmd_len = strlen(cmd);
 309        char *p = xmalloc(pre_len + cmd_len + 1);
 310        memcpy(p, prefix, pre_len);
 311        strcpy(p + pre_len, cmd);
 312        return p;
 313}
 314
 315static const char *cmd_to_page(const char *git_cmd)
 316{
 317        if (!git_cmd)
 318                return "git";
 319        else if (!prefixcmp(git_cmd, "git"))
 320                return git_cmd;
 321        else if (is_git_command(git_cmd))
 322                return prepend("git-", git_cmd);
 323        else
 324                return prepend("git", git_cmd);
 325}
 326
 327static void setup_man_path(void)
 328{
 329        struct strbuf new_path = STRBUF_INIT;
 330        const char *old_path = getenv("MANPATH");
 331
 332        /* We should always put ':' after our path. If there is no
 333         * old_path, the ':' at the end will let 'man' to try
 334         * system-wide paths after ours to find the manual page. If
 335         * there is old_path, we need ':' as delimiter. */
 336        strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
 337        strbuf_addch(&new_path, ':');
 338        if (old_path)
 339                strbuf_addstr(&new_path, old_path);
 340
 341        setenv("MANPATH", new_path.buf, 1);
 342
 343        strbuf_release(&new_path);
 344}
 345
 346static void exec_viewer(const char *name, const char *page)
 347{
 348        const char *info = get_man_viewer_info(name);
 349
 350        if (!strcasecmp(name, "man"))
 351                exec_man_man(info, page);
 352        else if (!strcasecmp(name, "woman"))
 353                exec_woman_emacs(info, page);
 354        else if (!strcasecmp(name, "konqueror"))
 355                exec_man_konqueror(info, page);
 356        else if (info)
 357                exec_man_cmd(info, page);
 358        else
 359                warning(_("'%s': unknown man viewer."), name);
 360}
 361
 362static void show_man_page(const char *git_cmd)
 363{
 364        struct man_viewer_list *viewer;
 365        const char *page = cmd_to_page(git_cmd);
 366        const char *fallback = getenv("GIT_MAN_VIEWER");
 367
 368        setup_man_path();
 369        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 370        {
 371                exec_viewer(viewer->name, page); /* will return when unable */
 372        }
 373        if (fallback)
 374                exec_viewer(fallback, page);
 375        exec_viewer("man", page);
 376        die(_("no man viewer handled the request"));
 377}
 378
 379static void show_info_page(const char *git_cmd)
 380{
 381        const char *page = cmd_to_page(git_cmd);
 382        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 383        execlp("info", "info", "gitman", page, (char *)NULL);
 384        die(_("no info viewer handled the request"));
 385}
 386
 387static void get_html_page_path(struct strbuf *page_path, const char *page)
 388{
 389        struct stat st;
 390        const char *html_path = system_path(GIT_HTML_PATH);
 391
 392        /* Check that we have a git documentation directory. */
 393        if (stat(mkpath("%s/git.html", html_path), &st)
 394            || !S_ISREG(st.st_mode))
 395                die(_("'%s': not a documentation directory."), html_path);
 396
 397        strbuf_init(page_path, 0);
 398        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 399}
 400
 401/*
 402 * If open_html is not defined in a platform-specific way (see for
 403 * example compat/mingw.h), we use the script web--browse to display
 404 * HTML.
 405 */
 406#ifndef open_html
 407static void open_html(const char *path)
 408{
 409        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 410}
 411#endif
 412
 413static void show_html_page(const char *git_cmd)
 414{
 415        const char *page = cmd_to_page(git_cmd);
 416        struct strbuf page_path; /* it leaks but we exec bellow */
 417
 418        get_html_page_path(&page_path, page);
 419
 420        open_html(page_path.buf);
 421}
 422
 423int cmd_help(int argc, const char **argv, const char *prefix)
 424{
 425        int nongit;
 426        const char *alias;
 427        enum help_format parsed_help_format;
 428        load_command_list("git-", &main_cmds, &other_cmds);
 429
 430        argc = parse_options(argc, argv, prefix, builtin_help_options,
 431                        builtin_help_usage, 0);
 432        parsed_help_format = help_format;
 433
 434        if (show_all) {
 435                git_config(git_help_config, NULL);
 436                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 437                list_commands(colopts, &main_cmds, &other_cmds);
 438                printf("%s\n", _(git_more_info_string));
 439                return 0;
 440        }
 441
 442        if (!argv[0]) {
 443                printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 444                list_common_cmds_help();
 445                printf("\n%s\n", _(git_more_info_string));
 446                return 0;
 447        }
 448
 449        setup_git_directory_gently(&nongit);
 450        git_config(git_help_config, NULL);
 451
 452        if (parsed_help_format == HELP_FORMAT_NONE)
 453                help_format = parse_help_format(DEFAULT_HELP_FORMAT);
 454        else
 455                help_format = parsed_help_format;
 456
 457        alias = alias_lookup(argv[0]);
 458        if (alias && !is_git_command(argv[0])) {
 459                printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
 460                return 0;
 461        }
 462
 463        switch (help_format) {
 464        case HELP_FORMAT_NONE:
 465        case HELP_FORMAT_MAN:
 466                show_man_page(argv[0]);
 467                break;
 468        case HELP_FORMAT_INFO:
 469                show_info_page(argv[0]);
 470                break;
 471        case HELP_FORMAT_WEB:
 472                show_html_page(argv[0]);
 473                break;
 474        }
 475
 476        return 0;
 477}