blob: da1e4f66bf136048359595c20fd7a7d63f57c9d8 [file] [log] [blame]
* Copyright(c) 2015-2017 Intel Corporation. All rights reserved.
* Copyright(c) 2008 Miklos Vajna. All rights reserved.
* Copyright(c) 2006 Linus Torvalds. All rights reserved.
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* General Public License for more details.
/* originally copied from perf and git */
* builtin-help.c
* Builtin help command
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <builtin.h>
#include <util/util.h>
#include <util/strbuf.h>
#include <subcmd/parse-options.h>
#define pr_err(x, ...) fprintf(stderr, x, ##__VA_ARGS__)
#define STRERR_BUFSIZE 128 /* For the buffer size of strerror_r */
static void exec_man_konqueror(const char *path, const char *page)
const char *display = getenv("DISPLAY");
if (display && *display) {
struct strbuf man_page = STRBUF_INIT;
const char *filename = "kfmclient";
char sbuf[STRERR_BUFSIZE];
/* 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";
strbuf_addf(&man_page, "man:%s(1)", page);
execlp(path, filename, "newTab", man_page.buf, NULL);
warning("failed to exec '%s': %s", path,
strerror_r(errno, sbuf, sizeof(sbuf)));
static void exec_man_man(const char *path, const char *page)
char sbuf[STRERR_BUFSIZE];
if (!path)
path = "man";
execlp(path, "man", page, NULL);
warning("failed to exec '%s': %s", path,
strerror_r(errno, sbuf, sizeof(sbuf)));
static char *cmd_to_page(const char *cmd, char **page, const char *util_name)
int rc;
if (!cmd)
rc = asprintf(page, "%s", util_name);
else if (!prefixcmp(cmd, util_name))
rc = asprintf(page, "%s", cmd);
rc = asprintf(page, "%s-%s", util_name, cmd);
if (rc < 0)
return NULL;
return *page;
static int is_absolute_path(const char *path)
return path[0] == '/';
static const char *system_path(const char *path)
static const char *prefix = PREFIX;
struct strbuf d = STRBUF_INIT;
if (is_absolute_path(path))
return path;
strbuf_addf(&d, "%s/%s", prefix, path);
path = strbuf_detach(&d, NULL);
return path;
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(NDCTL_MAN_PATH));
strbuf_addch(&new_path, ':');
if (old_path)
strbuf_addstr(&new_path, old_path);
setenv("MANPATH", new_path.buf, 1);
static void exec_viewer(const char *name, const char *page)
if (!strcasecmp(name, "man"))
exec_man_man(NULL, page);
else if (!strcasecmp(name, "konqueror"))
exec_man_konqueror(NULL, page);
warning("'%s': unknown man viewer.", name);
int help_show_man_page(const char *cmd, const char *util_name,
const char *viewer)
const char *fallback = getenv(viewer);
char *page;
page = cmd_to_page(cmd, &page, util_name);
if (!page)
return -1;
if (fallback)
exec_viewer(fallback, page);
exec_viewer("man", page);
pr_err("no man viewer handled the request");
return -1;