git/builtin/help.c
Jeff King eddda37144 convert strncpy to memcpy
strncpy is known to be a confusing function because of its
termination semantics.  These calls are all correct, but it
takes some examination to see why. In particular, every one
of them expects to copy up to the length limit, and then
makes some arrangement for terminating the result.

We can just use memcpy, along with noting explicitly how the
result is terminated (if it is not already obvious). That
should make it more clear to a reader that we are doing the
right thing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-05 11:08:06 -07:00

504 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) {
size_t len;
if (strip_suffix(path, "/konqueror", &len))
path = xstrfmt("%.*s/kfmclient", (int)len, path);
filename = basename((char *)path);
} 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(SHELL_PATH, SHELL_PATH, "-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));
memcpy((*p)->name, name, len); /* NUL-terminated by xcalloc */
}
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);
memcpy(new->name, name, len); /* NUL-terminated by xcalloc */
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 *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 xstrfmt("git-%s", git_cmd);
else
return xstrfmt("git%s", 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;
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);
free(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;
}