swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: f2906aa863381afb0015a9eb7fefad885d4e5a56 authored by Linus Torvalds on 06 June 2022, 00:18:54 UTC
Linux 5.19-rc1
Linux 5.19-rc1
Tip revision: f2906aa
builtin-help.c
// SPDX-License-Identifier: GPL-2.0
/*
* builtin-help.c
*
* Builtin help command
*/
#include "util/cache.h"
#include "util/config.h"
#include "util/strbuf.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 <linux/string.h>
#include <linux/zalloc.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.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);
strcpy((*p)->name, name);
}
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;
}