// SPDX-License-Identifier: GPL-2.0 /* * builtin-help.c * * Builtin help command */ #include "perf.h" #include "util/config.h" #include "builtin.h" #include <subcmd/exec-cmd.h> #include "common-cmds.h" #include <subcmd/parse-options.h> #include <subcmd/run-command.h> #include <subcmd/help.h> #include "util/debug.h" #include <linux/kernel.h> #include <errno.h> #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> static struct man_viewer_list { struct man_viewer_list *next; char name[0]; } *man_viewer_list; static struct man_viewer_info_list { struct man_viewer_info_list *next; const char *info; char name[0]; } *man_viewer_info_list; enum help_format { HELP_FORMAT_NONE, HELP_FORMAT_MAN, HELP_FORMAT_INFO, HELP_FORMAT_WEB, }; 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; pr_err("unrecognized help format '%s'", format); return HELP_FORMAT_NONE; } static const char *get_man_viewer_info(const char *name) { struct man_viewer_info_list *viewer; 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) { struct strbuf buffer = STRBUF_INIT; struct child_process ec_process; const char *argv_ec[] = { "emacsclient", "--version", NULL }; int version; int ret = -1; /* 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; } if (strbuf_read(&buffer, ec_process.err, 20) < 0) { fprintf(stderr, "Failed to read emacsclient version\n"); goto out; } 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 (!strstarts(buffer.buf, "emacsclient")) { fprintf(stderr, "Failed to parse emacsclient version.\n"); goto out; } version = atoi(buffer.buf + strlen("emacsclient")); if (version < 22) { fprintf(stderr, "emacsclient version '%d' too old (< 22).\n", version); } else ret = 0; out: strbuf_release(&buffer); return ret; } static void exec_failed(const char *cmd) { char sbuf[STRERR_BUFSIZE]; pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf))); } static void exec_woman_emacs(const char *path, const char *page) { if (!check_emacsclient_version()) { /* This works only with emacsclient version >= 22. */ char *man_page; if (!path) path = "emacsclient"; if (asprintf(&man_page, "(woman \"%s\")", page) > 0) { execlp(path, "emacsclient", "-e", man_page, NULL); free(man_page); } exec_failed(path); } } static void exec_man_konqueror(const char *path, const char *page) { const char *display = getenv("DISPLAY"); if (display && *display) { char *man_page; 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 = strdup(path); char *dest = strrchr(new, '/'); /* strlen("konqueror") == strlen("kfmclient") */ strcpy(dest + 1, "kfmclient"); path = new; } if (file) filename = file; } else path = "kfmclient"; if (asprintf(&man_page, "man:%s(1)", page) > 0) { execlp(path, filename, "newTab", man_page, NULL); free(man_page); } exec_failed(path); } } static void exec_man_man(const char *path, const char *page) { if (!path) path = "man"; execlp(path, "man", page, NULL); exec_failed(path); } static void exec_man_cmd(const char *cmd, const char *page) { char *shell_cmd; if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) { execl("/bin/sh", "sh", "-c", shell_cmd, NULL); free(shell_cmd); } exec_failed(cmd); } static void add_man_viewer(const char *name) { struct man_viewer_list **p = &man_viewer_list; size_t len = strlen(name); while (*p) p = &((*p)->next); *p = zalloc(sizeof(**p) + len + 1); strncpy((*p)->name, name, len); } static int supported_man_viewer(const char *name, size_t len) { return (!strncasecmp("man", name, len) || !strncasecmp("woman", name, len) || !strncasecmp("konqueror", name, len)); } static void do_add_man_viewer_info(const char *name, size_t len, const char *value) { struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1); strncpy(new->name, name, len); new->info = strdup(value); new->next = man_viewer_info_list; man_viewer_info_list = new; } static void unsupported_man_viewer(const char *name, const char *var) { pr_warning("'%s': path for unsupported man viewer.\n" "Please consider using 'man.<tool>.%s' instead.", name, var); } static int add_man_viewer_path(const char *name, size_t len, const char *value) { if (supported_man_viewer(name, len)) do_add_man_viewer_info(name, len, value); else unsupported_man_viewer(name, "cmd"); return 0; } static int add_man_viewer_cmd(const char *name, size_t len, const char *value) { if (supported_man_viewer(name, len)) unsupported_man_viewer(name, "path"); else do_add_man_viewer_info(name, len, value); return 0; } static int add_man_viewer_info(const char *var, const char *value) { const char *name = var + 4; const char *subkey = strrchr(name, '.'); if (!subkey) { pr_err("Config with no key for man viewer: %s", name); return -1; } 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); } pr_warning("'%s': unsupported man viewer sub key.", subkey); return 0; } static int perf_help_config(const char *var, const char *value, void *cb) { enum help_format *help_formatp = cb; if (!strcmp(var, "help.format")) { if (!value) return config_error_nonbool(var); *help_formatp = parse_help_format(value); if (*help_formatp == HELP_FORMAT_NONE) return -1; return 0; } if (!strcmp(var, "man.viewer")) { if (!value) return config_error_nonbool(var); add_man_viewer(value); return 0; } if (strstarts(var, "man.")) return add_man_viewer_info(var, value); return 0; } static struct cmdnames main_cmds, other_cmds; void list_common_cmds_help(void) { unsigned int i, longest = 0; for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { if (longest < strlen(common_cmds[i].name)) longest = strlen(common_cmds[i].name); } puts(" The most commonly used perf commands are:"); for (i = 0; i < ARRAY_SIZE(common_cmds); i++) { printf(" %-*s ", longest, common_cmds[i].name); puts(common_cmds[i].help); } } static const char *cmd_to_page(const char *perf_cmd) { char *s; if (!perf_cmd) return "perf"; else if (strstarts(perf_cmd, "perf")) return perf_cmd; return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s; } static void setup_man_path(void) { char *new_path; 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. */ if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) { setenv("MANPATH", new_path, 1); free(new_path); } else { pr_err("Unable to setup man 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 pr_warning("'%s': unknown man viewer.", name); } static int show_man_page(const char *perf_cmd) { struct man_viewer_list *viewer; const char *page = cmd_to_page(perf_cmd); const char *fallback = getenv("PERF_MAN_VIEWER"); 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); pr_err("no man viewer handled the request"); return -1; } static int show_info_page(const char *perf_cmd) { const char *page = cmd_to_page(perf_cmd); setenv("INFOPATH", system_path(PERF_INFO_PATH), 1); execlp("info", "info", "perfman", page, NULL); return -1; } static int get_html_page_path(char **page_path, const char *page) { struct stat st; const char *html_path = system_path(PERF_HTML_PATH); /* Check that we have a perf documentation directory. */ if (stat(mkpath("%s/perf.html", html_path), &st) || !S_ISREG(st.st_mode)) { pr_err("'%s': not a documentation directory.", html_path); return -1; } return asprintf(page_path, "%s/%s.html", html_path, page); } /* * 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 static void open_html(const char *path) { execl_cmd("web--browse", "-c", "help.browser", path, NULL); } #endif static int show_html_page(const char *perf_cmd) { const char *page = cmd_to_page(perf_cmd); char *page_path; /* it leaks but we exec bellow */ if (get_html_page_path(&page_path, page) < 0) return -1; open_html(page_path); return 0; } int cmd_help(int argc, const char **argv) { bool show_all = false; enum help_format help_format = HELP_FORMAT_MAN; struct option builtin_help_options[] = { OPT_BOOLEAN('a', "all", &show_all, "print all available commands"), OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN), OPT_SET_UINT('w', "web", &help_format, "show manual in web browser", HELP_FORMAT_WEB), OPT_SET_UINT('i', "info", &help_format, "show info page", HELP_FORMAT_INFO), OPT_END(), }; const char * const builtin_help_subcommands[] = { "buildid-cache", "buildid-list", "diff", "evlist", "help", "list", "record", "report", "bench", "stat", "timechart", "top", "annotate", "script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data", #ifdef HAVE_LIBELF_SUPPORT "probe", #endif #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT) "trace", #endif NULL }; const char *builtin_help_usage[] = { "perf help [--all] [--man|--web|--info] [command]", NULL }; int rc; load_command_list("perf-", &main_cmds, &other_cmds); rc = perf_config(perf_help_config, &help_format); if (rc) return rc; argc = parse_options_subcommand(argc, argv, builtin_help_options, builtin_help_subcommands, builtin_help_usage, 0); if (show_all) { printf("\n Usage: %s\n\n", perf_usage_string); list_commands("perf commands", &main_cmds, &other_cmds); printf(" %s\n\n", perf_more_info_string); return 0; } if (!argv[0]) { printf("\n usage: %s\n\n", perf_usage_string); list_common_cmds_help(); printf("\n %s\n\n", perf_more_info_string); return 0; } switch (help_format) { case HELP_FORMAT_MAN: rc = show_man_page(argv[0]); break; case HELP_FORMAT_INFO: rc = show_info_page(argv[0]); break; case HELP_FORMAT_WEB: rc = show_html_page(argv[0]); break; case HELP_FORMAT_NONE: /* fall-through */ default: rc = -1; break; } return rc; }