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