Documentation - More examples for git bisect
[gitweb.git] / builtin-help.c
index fb731cc9345e197e710aea611e9519f1e04e0ab8..9b57a746185719eb43c962c4adb96283657692e9 100644 (file)
 /*
  * builtin-help.c
  *
- * Builtin help-related commands (help, usage, version)
+ * Builtin help command
  */
-#include <sys/ioctl.h>
 #include "cache.h"
 #include "builtin.h"
 #include "exec_cmd.h"
 #include "common-cmds.h"
+#include "parse-options.h"
+#include "run-command.h"
+#include "help.h"
+
+static struct man_viewer_list {
+       struct man_viewer_list *next;
+       char name[FLEX_ARRAY];
+} *man_viewer_list;
+
+static struct man_viewer_info_list {
+       struct man_viewer_info_list *next;
+       const char *info;
+       char name[FLEX_ARRAY];
+} *man_viewer_info_list;
+
+enum help_format {
+       HELP_FORMAT_MAN,
+       HELP_FORMAT_INFO,
+       HELP_FORMAT_WEB,
+};
+
+static int show_all = 0;
+static enum help_format help_format = HELP_FORMAT_MAN;
+static struct option builtin_help_options[] = {
+       OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
+       OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
+       OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
+                       HELP_FORMAT_WEB),
+       OPT_SET_INT('i', "info", &help_format, "show info page",
+                       HELP_FORMAT_INFO),
+       OPT_END(),
+};
+
+static const char * const builtin_help_usage[] = {
+       "git help [--all] [--man|--web|--info] [command]",
+       NULL
+};
+
+static enum help_format parse_help_format(const char *format)
+{
+       if (!strcmp(format, "man"))
+               return HELP_FORMAT_MAN;
+       if (!strcmp(format, "info"))
+               return HELP_FORMAT_INFO;
+       if (!strcmp(format, "web") || !strcmp(format, "html"))
+               return HELP_FORMAT_WEB;
+       die("unrecognized help format '%s'", format);
+}
 
+static const char *get_man_viewer_info(const char *name)
+{
+       struct man_viewer_info_list *viewer;
 
-/* most GUI terminals set COLUMNS (although some don't export it) */
-static int term_columns(void)
+       for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
+       {
+               if (!strcasecmp(name, viewer->name))
+                       return viewer->info;
+       }
+       return NULL;
+}
+
+static int check_emacsclient_version(void)
 {
-       char *col_string = getenv("COLUMNS");
-       int n_cols = 0;
+       struct strbuf buffer = STRBUF_INIT;
+       struct child_process ec_process;
+       const char *argv_ec[] = { "emacsclient", "--version", NULL };
+       int version;
+
+       /* emacsclient prints its version number on stderr */
+       memset(&ec_process, 0, sizeof(ec_process));
+       ec_process.argv = argv_ec;
+       ec_process.err = -1;
+       ec_process.stdout_to_stderr = 1;
+       if (start_command(&ec_process)) {
+               fprintf(stderr, "Failed to start emacsclient.\n");
+               return -1;
+       }
+       strbuf_read(&buffer, ec_process.err, 20);
+       close(ec_process.err);
+
+       /*
+        * Don't bother checking return value, because "emacsclient --version"
+        * seems to always exits with code 1.
+        */
+       finish_command(&ec_process);
+
+       if (prefixcmp(buffer.buf, "emacsclient")) {
+               fprintf(stderr, "Failed to parse emacsclient version.\n");
+               strbuf_release(&buffer);
+               return -1;
+       }
 
-       if (col_string && (n_cols = atoi(col_string)) > 0)
-               return n_cols;
+       strbuf_remove(&buffer, 0, strlen("emacsclient"));
+       version = atoi(buffer.buf);
 
-#ifdef TIOCGWINSZ
-       {
-               struct winsize ws;
-               if (!ioctl(1, TIOCGWINSZ, &ws)) {
-                       if (ws.ws_col)
-                               return ws.ws_col;
-               }
+       if (version < 22) {
+               fprintf(stderr,
+                       "emacsclient version '%d' too old (< 22).\n",
+                       version);
+               strbuf_release(&buffer);
+               return -1;
        }
-#endif
 
-       return 80;
+       strbuf_release(&buffer);
+       return 0;
 }
 
-static void oom(void)
+static void exec_woman_emacs(const char* path, const char *page)
 {
-       fprintf(stderr, "git: out of memory\n");
-       exit(1);
+       if (!check_emacsclient_version()) {
+               /* This works only with emacsclient version >= 22. */
+               struct strbuf man_page = STRBUF_INIT;
+
+               if (!path)
+                       path = "emacsclient";
+               strbuf_addf(&man_page, "(woman \"%s\")", page);
+               execlp(path, "emacsclient", "-e", man_page.buf, NULL);
+               warning("failed to exec '%s': %s", path, strerror(errno));
+       }
 }
 
-static inline void mput_char(char c, unsigned int num)
+static void exec_man_konqueror(const char* path, const char *page)
 {
-       while(num--)
-               putchar(c);
+       const char *display = getenv("DISPLAY");
+       if (display && *display) {
+               struct strbuf man_page = STRBUF_INIT;
+               const char *filename = "kfmclient";
+
+               /* It's simpler to launch konqueror using kfmclient. */
+               if (path) {
+                       const char *file = strrchr(path, '/');
+                       if (file && !strcmp(file + 1, "konqueror")) {
+                               char *new = xstrdup(path);
+                               char *dest = strrchr(new, '/');
+
+                               /* strlen("konqueror") == strlen("kfmclient") */
+                               strcpy(dest + 1, "kfmclient");
+                               path = new;
+                       }
+                       if (file)
+                               filename = file;
+               } else
+                       path = "kfmclient";
+               strbuf_addf(&man_page, "man:%s(1)", page);
+               execlp(path, filename, "newTab", man_page.buf, NULL);
+               warning("failed to exec '%s': %s", path, strerror(errno));
+       }
 }
 
-static struct cmdname {
-       size_t len;
-       char name[1];
-} **cmdname;
-static int cmdname_alloc, cmdname_cnt;
-
-static void add_cmdname(const char *name, int len)
+static void exec_man_man(const char* path, const char *page)
 {
-       struct cmdname *ent;
-       if (cmdname_alloc <= cmdname_cnt) {
-               cmdname_alloc = cmdname_alloc + 200;
-               cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
-               if (!cmdname)
-                       oom();
-       }
-       ent = malloc(sizeof(*ent) + len);
-       if (!ent)
-               oom();
-       ent->len = len;
-       memcpy(ent->name, name, len);
-       ent->name[len] = 0;
-       cmdname[cmdname_cnt++] = ent;
+       if (!path)
+               path = "man";
+       execlp(path, "man", page, NULL);
+       warning("failed to exec '%s': %s", path, strerror(errno));
 }
 
-static int cmdname_compare(const void *a_, const void *b_)
+static void exec_man_cmd(const char *cmd, const char *page)
 {
-       struct cmdname *a = *(struct cmdname **)a_;
-       struct cmdname *b = *(struct cmdname **)b_;
-       return strcmp(a->name, b->name);
+       struct strbuf shell_cmd = STRBUF_INIT;
+       strbuf_addf(&shell_cmd, "%s %s", cmd, page);
+       execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
+       warning("failed to exec '%s': %s", cmd, strerror(errno));
 }
 
-static void pretty_print_string_list(struct cmdname **cmdname, int longest)
+static void add_man_viewer(const char *name)
 {
-       int cols = 1, rows;
-       int space = longest + 1; /* min 1 SP between words */
-       int max_cols = term_columns() - 1; /* don't print *on* the edge */
-       int i, j;
+       struct man_viewer_list **p = &man_viewer_list;
+       size_t len = strlen(name);
 
-       if (space < max_cols)
-               cols = max_cols / space;
-       rows = (cmdname_cnt + cols - 1) / cols;
+       while (*p)
+               p = &((*p)->next);
+       *p = xcalloc(1, (sizeof(**p) + len + 1));
+       strncpy((*p)->name, name, len);
+}
 
-       qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
+static int supported_man_viewer(const char *name, size_t len)
+{
+       return (!strncasecmp("man", name, len) ||
+               !strncasecmp("woman", name, len) ||
+               !strncasecmp("konqueror", name, len));
+}
 
-       for (i = 0; i < rows; i++) {
-               printf("  ");
+static void do_add_man_viewer_info(const char *name,
+                                  size_t len,
+                                  const char *value)
+{
+       struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 
-               for (j = 0; j < cols; j++) {
-                       int n = j * rows + i;
-                       int size = space;
-                       if (n >= cmdname_cnt)
-                               break;
-                       if (j == cols-1 || n + rows >= cmdname_cnt)
-                               size = 1;
-                       printf("%-*s", size, cmdname[n]->name);
-               }
-               putchar('\n');
-       }
+       strncpy(new->name, name, len);
+       new->info = xstrdup(value);
+       new->next = man_viewer_info_list;
+       man_viewer_info_list = new;
 }
 
-static void list_commands(const char *exec_path, const char *pattern)
+static int add_man_viewer_path(const char *name,
+                              size_t len,
+                              const char *value)
 {
-       unsigned int longest = 0;
-       char path[PATH_MAX];
-       int dirlen;
-       DIR *dir = opendir(exec_path);
-       struct dirent *de;
+       if (supported_man_viewer(name, len))
+               do_add_man_viewer_info(name, len, value);
+       else
+               warning("'%s': path for unsupported man viewer.\n"
+                       "Please consider using 'man.<tool>.cmd' instead.",
+                       name);
 
-       if (!dir) {
-               fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
-               exit(1);
-       }
+       return 0;
+}
 
-       dirlen = strlen(exec_path);
-       if (PATH_MAX - 20 < dirlen) {
-               fprintf(stderr, "git: insanely long exec-path '%s'\n",
-                       exec_path);
-               exit(1);
-       }
+static int add_man_viewer_cmd(const char *name,
+                             size_t len,
+                             const char *value)
+{
+       if (supported_man_viewer(name, len))
+               warning("'%s': cmd for supported man viewer.\n"
+                       "Please consider using 'man.<tool>.path' instead.",
+                       name);
+       else
+               do_add_man_viewer_info(name, len, value);
 
-       memcpy(path, exec_path, dirlen);
-       path[dirlen++] = '/';
+       return 0;
+}
 
-       while ((de = readdir(dir)) != NULL) {
-               struct stat st;
-               int entlen;
+static int add_man_viewer_info(const char *var, const char *value)
+{
+       const char *name = var + 4;
+       const char *subkey = strrchr(name, '.');
 
-               if (strncmp(de->d_name, "git-", 4))
-                       continue;
-               strcpy(path+dirlen, de->d_name);
-               if (stat(path, &st) || /* stat, not lstat */
-                   !S_ISREG(st.st_mode) ||
-                   !(st.st_mode & S_IXUSR))
-                       continue;
+       if (!subkey)
+               return error("Config with no key for man viewer: %s", name);
 
-               entlen = strlen(de->d_name);
-               if (4 < entlen && !strcmp(de->d_name + entlen - 4, ".exe"))
-                       entlen -= 4;
+       if (!strcmp(subkey, ".path")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               return add_man_viewer_path(name, subkey - name, value);
+       }
+       if (!strcmp(subkey, ".cmd")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               return add_man_viewer_cmd(name, subkey - name, value);
+       }
 
-               if (longest < entlen)
-                       longest = entlen;
+       warning("'%s': unsupported man viewer sub key.", subkey);
+       return 0;
+}
 
-               add_cmdname(de->d_name + 4, entlen-4);
+static int git_help_config(const char *var, const char *value, void *cb)
+{
+       if (!strcmp(var, "help.format")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               help_format = parse_help_format(value);
+               return 0;
        }
-       closedir(dir);
+       if (!strcmp(var, "man.viewer")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               add_man_viewer(value);
+               return 0;
+       }
+       if (!prefixcmp(var, "man."))
+               return add_man_viewer_info(var, value);
 
-       printf("git commands available in '%s'\n", exec_path);
-       printf("----------------------------");
-       mput_char('-', strlen(exec_path));
-       putchar('\n');
-       pretty_print_string_list(cmdname, longest - 4);
-       putchar('\n');
+       return git_default_config(var, value, cb);
 }
 
-static void list_common_cmds_help(void)
+static struct cmdnames main_cmds, other_cmds;
+
+void list_common_cmds_help(void)
 {
        int i, longest = 0;
 
@@ -169,66 +286,178 @@ static void list_common_cmds_help(void)
 
        puts("The most commonly used git commands are:");
        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
-               printf("    %s", common_cmds[i].name);
-               mput_char(' ', longest - strlen(common_cmds[i].name) + 4);
+               printf("   %s   ", common_cmds[i].name);
+               mput_char(' ', longest - strlen(common_cmds[i].name));
                puts(common_cmds[i].help);
        }
-       puts("(use 'git help -a' to get a list of all installed git commands)");
+}
+
+static int is_git_command(const char *s)
+{
+       return is_in_cmdlist(&main_cmds, s) ||
+               is_in_cmdlist(&other_cmds, s);
+}
+
+static const char *prepend(const char *prefix, const char *cmd)
+{
+       size_t pre_len = strlen(prefix);
+       size_t cmd_len = strlen(cmd);
+       char *p = xmalloc(pre_len + cmd_len + 1);
+       memcpy(p, prefix, pre_len);
+       strcpy(p + pre_len, cmd);
+       return p;
+}
+
+static const char *cmd_to_page(const char *git_cmd)
+{
+       if (!git_cmd)
+               return "git";
+       else if (!prefixcmp(git_cmd, "git"))
+               return git_cmd;
+       else if (is_git_command(git_cmd))
+               return prepend("git-", git_cmd);
+       else
+               return prepend("git", git_cmd);
+}
+
+static void setup_man_path(void)
+{
+       struct strbuf new_path = STRBUF_INIT;
+       const char *old_path = getenv("MANPATH");
+
+       /* We should always put ':' after our path. If there is no
+        * old_path, the ':' at the end will let 'man' to try
+        * system-wide paths after ours to find the manual page. If
+        * there is old_path, we need ':' as delimiter. */
+       strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
+       strbuf_addch(&new_path, ':');
+       if (old_path)
+               strbuf_addstr(&new_path, old_path);
+
+       setenv("MANPATH", new_path.buf, 1);
+
+       strbuf_release(&new_path);
+}
+
+static void exec_viewer(const char *name, const char *page)
+{
+       const char *info = get_man_viewer_info(name);
+
+       if (!strcasecmp(name, "man"))
+               exec_man_man(info, page);
+       else if (!strcasecmp(name, "woman"))
+               exec_woman_emacs(info, page);
+       else if (!strcasecmp(name, "konqueror"))
+               exec_man_konqueror(info, page);
+       else if (info)
+               exec_man_cmd(info, page);
+       else
+               warning("'%s': unknown man viewer.", name);
 }
 
 static void show_man_page(const char *git_cmd)
 {
-       const char *page;
+       struct man_viewer_list *viewer;
+       const char *page = cmd_to_page(git_cmd);
+       const char *fallback = getenv("GIT_MAN_VIEWER");
 
-       if (!strncmp(git_cmd, "git", 3))
-               page = git_cmd;
-       else {
-               int page_len = strlen(git_cmd) + 4;
-               char *p = malloc(page_len + 1);
-               strcpy(p, "git-");
-               strcpy(p + 4, git_cmd);
-               p[page_len] = 0;
-               page = p;
+       setup_man_path();
+       for (viewer = man_viewer_list; viewer; viewer = viewer->next)
+       {
+               exec_viewer(viewer->name, page); /* will return when unable */
        }
+       if (fallback)
+               exec_viewer(fallback, page);
+       exec_viewer("man", page);
+       die("no man viewer handled the request");
+}
 
-       execlp("man", "man", page, NULL);
+static void show_info_page(const char *git_cmd)
+{
+       const char *page = cmd_to_page(git_cmd);
+       setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
+       execlp("info", "info", "gitman", page, NULL);
 }
 
-void help_unknown_cmd(const char *cmd)
+static void get_html_page_path(struct strbuf *page_path, const char *page)
 {
-       printf("git: '%s' is not a git-command\n\n", cmd);
-       list_common_cmds_help();
-       exit(1);
+       struct stat st;
+       const char *html_path = system_path(GIT_HTML_PATH);
+
+       /* Check that we have a git documentation directory. */
+       if (stat(mkpath("%s/git.html", html_path), &st)
+           || !S_ISREG(st.st_mode))
+               die("'%s': not a documentation directory.", html_path);
+
+       strbuf_init(page_path, 0);
+       strbuf_addf(page_path, "%s/%s.html", html_path, page);
 }
 
-int cmd_version(int argc, const char **argv, const char *prefix)
+/*
+ * If open_html is not defined in a platform-specific way (see for
+ * example compat/mingw.h), we use the script web--browse to display
+ * HTML.
+ */
+#ifndef open_html
+void open_html(const char *path)
 {
-       printf("git version %s\n", git_version_string);
-       return 0;
+       execl_git_cmd("web--browse", "-c", "help.browser", path, NULL);
+}
+#endif
+
+static void show_html_page(const char *git_cmd)
+{
+       const char *page = cmd_to_page(git_cmd);
+       struct strbuf page_path; /* it leaks but we exec bellow */
+
+       get_html_page_path(&page_path, page);
+
+       open_html(page_path.buf);
 }
 
 int cmd_help(int argc, const char **argv, const char *prefix)
 {
-       const char *help_cmd = argc > 1 ? argv[1] : NULL;
-       const char *exec_path = git_exec_path();
+       int nongit;
+       const char *alias;
+       load_command_list("git-", &main_cmds, &other_cmds);
 
-       if (!help_cmd) {
+       setup_git_directory_gently(&nongit);
+       git_config(git_help_config, NULL);
+
+       argc = parse_options(argc, argv, builtin_help_options,
+                       builtin_help_usage, 0);
+
+       if (show_all) {
                printf("usage: %s\n\n", git_usage_string);
-               list_common_cmds_help();
-               exit(1);
+               list_commands("git commands", &main_cmds, &other_cmds);
+               printf("%s\n", git_more_info_string);
+               return 0;
        }
 
-       else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
+       if (!argv[0]) {
                printf("usage: %s\n\n", git_usage_string);
-               if(exec_path)
-                       list_commands(exec_path, "git-*");
-               exit(1);
+               list_common_cmds_help();
+               printf("\n%s\n", git_more_info_string);
+               return 0;
        }
 
-       else
-               show_man_page(help_cmd);
+       alias = alias_lookup(argv[0]);
+       if (alias && !is_git_command(argv[0])) {
+               printf("`git %s' is aliased to `%s'\n", argv[0], alias);
+               return 0;
+       }
+
+       switch (help_format) {
+       case HELP_FORMAT_MAN:
+               show_man_page(argv[0]);
+               break;
+       case HELP_FORMAT_INFO:
+               show_info_page(argv[0]);
+               break;
+       case HELP_FORMAT_WEB:
+               show_html_page(argv[0]);
+               break;
+       }
 
        return 0;
 }
-
-