git/builtin/help.c
Junio C Hamano 6bcaff1a4f Merge branch 'jc/exec-cmd-system-path-leak-fix'
The function sometimes returned a non-freeable memory and some
other times returned a piece of memory that must be freed.

* jc/exec-cmd-system-path-leak-fix:
  system_path(): always return free'able memory to the caller
2014-12-22 12:27:01 -08:00

520 lines
13 KiB
C

/*
* Builtin help command
*/
#include "cache.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "parse-options.h"
#include "run-command.h"
#include "column.h"
#include "help.h"
#ifndef DEFAULT_HELP_FORMAT
#define DEFAULT_HELP_FORMAT "man"
#endif
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_NONE,
HELP_FORMAT_MAN,
HELP_FORMAT_INFO,
HELP_FORMAT_WEB
};
static const char *html_path;
static int show_all = 0;
static int show_guides = 0;
static unsigned int colopts;
static enum help_format help_format = HELP_FORMAT_NONE;
static struct option builtin_help_options[] = {
OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
HELP_FORMAT_WEB),
OPT_SET_INT('i', "info", &help_format, N_("show info page"),
HELP_FORMAT_INFO),
OPT_END(),
};
static const char * const builtin_help_usage[] = {
N_("git help [--all] [--guides] [--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;
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 = CHILD_PROCESS_INIT;
const char *argv_ec[] = { "emacsclient", "--version", NULL };
int version;
/* emacsclient prints its version number on stderr */
ec_process.argv = argv_ec;
ec_process.err = -1;
ec_process.stdout_to_stderr = 1;
if (start_command(&ec_process))
return error(_("Failed to start emacsclient."));
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 (!starts_with(buffer.buf, "emacsclient")) {
strbuf_release(&buffer);
return error(_("Failed to parse emacsclient version."));
}
strbuf_remove(&buffer, 0, strlen("emacsclient"));
version = atoi(buffer.buf);
if (version < 22) {
strbuf_release(&buffer);
return error(_("emacsclient version '%d' too old (< 22)."),
version);
}
strbuf_release(&buffer);
return 0;
}
static void exec_woman_emacs(const char *path, const char *page)
{
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, (char *)NULL);
warning(_("failed to exec '%s': %s"), path, strerror(errno));
}
}
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";
/* 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, (char *)NULL);
warning(_("failed to exec '%s': %s"), path, strerror(errno));
}
}
static void exec_man_man(const char *path, const char *page)
{
if (!path)
path = "man";
execlp(path, "man", page, (char *)NULL);
warning(_("failed to exec '%s': %s"), path, strerror(errno));
}
static void exec_man_cmd(const char *cmd, const char *page)
{
struct strbuf shell_cmd = STRBUF_INIT;
strbuf_addf(&shell_cmd, "%s %s", cmd, page);
execl("/bin/sh", "sh", "-c", shell_cmd.buf, (char *)NULL);
warning(_("failed to exec '%s': %s"), cmd, strerror(errno));
}
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 = xcalloc(1, (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 = xcalloc(1, sizeof(*new) + len + 1);
strncpy(new->name, name, len);
new->info = xstrdup(value);
new->next = man_viewer_info_list;
man_viewer_info_list = new;
}
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
warning(_("'%s': path for unsupported man viewer.\n"
"Please consider using 'man.<tool>.cmd' instead."),
name);
return 0;
}
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);
return 0;
}
static int add_man_viewer_info(const char *var, const char *value)
{
const char *name, *subkey;
int namelen;
if (parse_config_key(var, "man", &name, &namelen, &subkey) < 0 || !name)
return 0;
if (!strcmp(subkey, "path")) {
if (!value)
return config_error_nonbool(var);
return add_man_viewer_path(name, namelen, value);
}
if (!strcmp(subkey, "cmd")) {
if (!value)
return config_error_nonbool(var);
return add_man_viewer_cmd(name, namelen, value);
}
return 0;
}
static int git_help_config(const char *var, const char *value, void *cb)
{
if (starts_with(var, "column."))
return git_column_config(var, value, "help", &colopts);
if (!strcmp(var, "help.format")) {
if (!value)
return config_error_nonbool(var);
help_format = parse_help_format(value);
return 0;
}
if (!strcmp(var, "help.htmlpath")) {
if (!value)
return config_error_nonbool(var);
html_path = xstrdup(value);
return 0;
}
if (!strcmp(var, "man.viewer")) {
if (!value)
return config_error_nonbool(var);
add_man_viewer(value);
return 0;
}
if (starts_with(var, "man."))
return add_man_viewer_info(var, value);
return git_default_config(var, value, cb);
}
static struct cmdnames main_cmds, other_cmds;
static int is_git_command(const char *s)
{
if (is_builtin(s))
return 1;
load_command_list("git-", &main_cmds, &other_cmds);
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 (starts_with(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");
char *git_man_path = system_path(GIT_MAN_PATH);
/* 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, git_man_path);
strbuf_addch(&new_path, ':');
if (old_path)
strbuf_addstr(&new_path, old_path);
free(git_man_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)
{
struct man_viewer_list *viewer;
const char *page = cmd_to_page(git_cmd);
const char *fallback = getenv("GIT_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);
die(_("no man viewer handled the request"));
}
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, (char *)NULL);
die(_("no info viewer handled the request"));
}
static void get_html_page_path(struct strbuf *page_path, const char *page)
{
struct stat st;
char *to_free = NULL;
if (!html_path)
html_path = to_free = system_path(GIT_HTML_PATH);
/* Check that we have a git documentation directory. */
if (!strstr(html_path, "://")) {
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);
free(to_free);
}
/*
* 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_git_cmd("web--browse", "-c", "help.browser", path, (char *)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);
}
static struct {
const char *name;
const char *help;
} common_guides[] = {
{ "attributes", N_("Defining attributes per path") },
{ "everyday", N_("Everyday Git With 20 Commands Or So") },
{ "glossary", N_("A Git glossary") },
{ "ignore", N_("Specifies intentionally untracked files to ignore") },
{ "modules", N_("Defining submodule properties") },
{ "revisions", N_("Specifying revisions and ranges for Git") },
{ "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
{ "workflows", N_("An overview of recommended workflows with Git") },
};
static void list_common_guides_help(void)
{
int i, longest = 0;
for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
if (longest < strlen(common_guides[i].name))
longest = strlen(common_guides[i].name);
}
puts(_("The common Git guides are:\n"));
for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
printf(" %s ", common_guides[i].name);
mput_char(' ', longest - strlen(common_guides[i].name));
puts(_(common_guides[i].help));
}
putchar('\n');
}
int cmd_help(int argc, const char **argv, const char *prefix)
{
int nongit;
const char *alias;
enum help_format parsed_help_format;
argc = parse_options(argc, argv, prefix, builtin_help_options,
builtin_help_usage, 0);
parsed_help_format = help_format;
if (show_all) {
git_config(git_help_config, NULL);
printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
load_command_list("git-", &main_cmds, &other_cmds);
list_commands(colopts, &main_cmds, &other_cmds);
}
if (show_guides)
list_common_guides_help();
if (show_all || show_guides) {
printf("%s\n", _(git_more_info_string));
/*
* We're done. Ignore any remaining args
*/
return 0;
}
if (!argv[0]) {
printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
list_common_cmds_help();
printf("\n%s\n", _(git_more_info_string));
return 0;
}
setup_git_directory_gently(&nongit);
git_config(git_help_config, NULL);
if (parsed_help_format != HELP_FORMAT_NONE)
help_format = parsed_help_format;
if (help_format == HELP_FORMAT_NONE)
help_format = parse_help_format(DEFAULT_HELP_FORMAT);
alias = alias_lookup(argv[0]);
if (alias && !is_git_command(argv[0])) {
printf_ln(_("`git %s' is aliased to `%s'"), argv[0], alias);
return 0;
}
switch (help_format) {
case HELP_FORMAT_NONE:
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;
}