git/help.c
Michael Schubert 823e0ded8a help_unknown_cmd: do not propose an "unknown" cmd
When executing an external shell script like `git foo` with a bad
shebang, e.g. "#!/usr/bin/not/existing", execvp returns 127 (ENOENT).

Since help_unknown_cmd proposes the use of all external commands similar
to the name of the "unknown" command, it suggests the just failed command
again. Stop it and give some advice to the user.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-07-08 08:59:44 -07:00

414 lines
9.8 KiB
C

#include "cache.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "levenshtein.h"
#include "help.h"
#include "common-cmds.h"
/* most GUI terminals set COLUMNS (although some don't export it) */
static int term_columns(void)
{
char *col_string = getenv("COLUMNS");
int n_cols;
if (col_string && (n_cols = atoi(col_string)) > 0)
return n_cols;
#ifdef TIOCGWINSZ
{
struct winsize ws;
if (!ioctl(1, TIOCGWINSZ, &ws)) {
if (ws.ws_col)
return ws.ws_col;
}
}
#endif
return 80;
}
void add_cmdname(struct cmdnames *cmds, const char *name, int len)
{
struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
ent->len = len;
memcpy(ent->name, name, len);
ent->name[len] = 0;
ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
cmds->names[cmds->cnt++] = ent;
}
static void clean_cmdnames(struct cmdnames *cmds)
{
int i;
for (i = 0; i < cmds->cnt; ++i)
free(cmds->names[i]);
free(cmds->names);
cmds->cnt = 0;
cmds->alloc = 0;
}
static int cmdname_compare(const void *a_, const void *b_)
{
struct cmdname *a = *(struct cmdname **)a_;
struct cmdname *b = *(struct cmdname **)b_;
return strcmp(a->name, b->name);
}
static void uniq(struct cmdnames *cmds)
{
int i, j;
if (!cmds->cnt)
return;
for (i = j = 1; i < cmds->cnt; i++)
if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
cmds->names[j++] = cmds->names[i];
cmds->cnt = j;
}
void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
{
int ci, cj, ei;
int cmp;
ci = cj = ei = 0;
while (ci < cmds->cnt && ei < excludes->cnt) {
cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
if (cmp < 0)
cmds->names[cj++] = cmds->names[ci++];
else if (cmp == 0)
ci++, ei++;
else if (cmp > 0)
ei++;
}
while (ci < cmds->cnt)
cmds->names[cj++] = cmds->names[ci++];
cmds->cnt = cj;
}
static void pretty_print_string_list(struct cmdnames *cmds, int longest)
{
int cols = 1, rows;
int space = longest + 1; /* min 1 SP between words */
int max_cols = term_columns() - 1; /* don't print *on* the edge */
int i, j;
if (space < max_cols)
cols = max_cols / space;
rows = DIV_ROUND_UP(cmds->cnt, cols);
for (i = 0; i < rows; i++) {
printf(" ");
for (j = 0; j < cols; j++) {
int n = j * rows + i;
int size = space;
if (n >= cmds->cnt)
break;
if (j == cols-1 || n + rows >= cmds->cnt)
size = 1;
printf("%-*s", size, cmds->names[n]->name);
}
putchar('\n');
}
}
static int is_executable(const char *name)
{
struct stat st;
if (stat(name, &st) || /* stat, not lstat */
!S_ISREG(st.st_mode))
return 0;
#ifdef WIN32
{ /* cannot trust the executable bit, peek into the file instead */
char buf[3] = { 0 };
int n;
int fd = open(name, O_RDONLY);
st.st_mode &= ~S_IXUSR;
if (fd >= 0) {
n = read(fd, buf, 2);
if (n == 2)
/* DOS executables start with "MZ" */
if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
st.st_mode |= S_IXUSR;
close(fd);
}
}
#endif
return st.st_mode & S_IXUSR;
}
static void list_commands_in_dir(struct cmdnames *cmds,
const char *path,
const char *prefix)
{
int prefix_len;
DIR *dir = opendir(path);
struct dirent *de;
struct strbuf buf = STRBUF_INIT;
int len;
if (!dir)
return;
if (!prefix)
prefix = "git-";
prefix_len = strlen(prefix);
strbuf_addf(&buf, "%s/", path);
len = buf.len;
while ((de = readdir(dir)) != NULL) {
int entlen;
if (prefixcmp(de->d_name, prefix))
continue;
strbuf_setlen(&buf, len);
strbuf_addstr(&buf, de->d_name);
if (!is_executable(buf.buf))
continue;
entlen = strlen(de->d_name) - prefix_len;
if (has_extension(de->d_name, ".exe"))
entlen -= 4;
add_cmdname(cmds, de->d_name + prefix_len, entlen);
}
closedir(dir);
strbuf_release(&buf);
}
void load_command_list(const char *prefix,
struct cmdnames *main_cmds,
struct cmdnames *other_cmds)
{
const char *env_path = getenv("PATH");
const char *exec_path = git_exec_path();
if (exec_path) {
list_commands_in_dir(main_cmds, exec_path, prefix);
qsort(main_cmds->names, main_cmds->cnt,
sizeof(*main_cmds->names), cmdname_compare);
uniq(main_cmds);
}
if (env_path) {
char *paths, *path, *colon;
path = paths = xstrdup(env_path);
while (1) {
if ((colon = strchr(path, PATH_SEP)))
*colon = 0;
if (!exec_path || strcmp(path, exec_path))
list_commands_in_dir(other_cmds, path, prefix);
if (!colon)
break;
path = colon + 1;
}
free(paths);
qsort(other_cmds->names, other_cmds->cnt,
sizeof(*other_cmds->names), cmdname_compare);
uniq(other_cmds);
}
exclude_cmds(other_cmds, main_cmds);
}
void list_commands(const char *title, struct cmdnames *main_cmds,
struct cmdnames *other_cmds)
{
int i, longest = 0;
for (i = 0; i < main_cmds->cnt; i++)
if (longest < main_cmds->names[i]->len)
longest = main_cmds->names[i]->len;
for (i = 0; i < other_cmds->cnt; i++)
if (longest < other_cmds->names[i]->len)
longest = other_cmds->names[i]->len;
if (main_cmds->cnt) {
const char *exec_path = git_exec_path();
printf("available %s in '%s'\n", title, exec_path);
printf("----------------");
mput_char('-', strlen(title) + strlen(exec_path));
putchar('\n');
pretty_print_string_list(main_cmds, longest);
putchar('\n');
}
if (other_cmds->cnt) {
printf("%s available from elsewhere on your $PATH\n", title);
printf("---------------------------------------");
mput_char('-', strlen(title));
putchar('\n');
pretty_print_string_list(other_cmds, longest);
putchar('\n');
}
}
int is_in_cmdlist(struct cmdnames *c, const char *s)
{
int i;
for (i = 0; i < c->cnt; i++)
if (!strcmp(s, c->names[i]->name))
return 1;
return 0;
}
static int autocorrect;
static struct cmdnames aliases;
static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "help.autocorrect"))
autocorrect = git_config_int(var,value);
/* Also use aliases for command lookup */
if (!prefixcmp(var, "alias."))
add_cmdname(&aliases, var + 6, strlen(var + 6));
return git_default_config(var, value, cb);
}
static int levenshtein_compare(const void *p1, const void *p2)
{
const struct cmdname *const *c1 = p1, *const *c2 = p2;
const char *s1 = (*c1)->name, *s2 = (*c2)->name;
int l1 = (*c1)->len;
int l2 = (*c2)->len;
return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
}
static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
{
int i;
ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
for (i = 0; i < old->cnt; i++)
cmds->names[cmds->cnt++] = old->names[i];
free(old->names);
old->cnt = 0;
old->names = NULL;
}
/* An empirically derived magic number */
#define SIMILARITY_FLOOR 7
#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
static const char bad_interpreter_advice[] =
N_("'%s' appears to be a git command, but we were not\n"
"able to execute it. Maybe git-%s is broken?");
const char *help_unknown_cmd(const char *cmd)
{
int i, n, best_similarity = 0;
struct cmdnames main_cmds, other_cmds;
memset(&main_cmds, 0, sizeof(main_cmds));
memset(&other_cmds, 0, sizeof(other_cmds));
memset(&aliases, 0, sizeof(aliases));
git_config(git_unknown_cmd_config, NULL);
load_command_list("git-", &main_cmds, &other_cmds);
add_cmd_list(&main_cmds, &aliases);
add_cmd_list(&main_cmds, &other_cmds);
qsort(main_cmds.names, main_cmds.cnt,
sizeof(main_cmds.names), cmdname_compare);
uniq(&main_cmds);
/* This abuses cmdname->len for levenshtein distance */
for (i = 0, n = 0; i < main_cmds.cnt; i++) {
int cmp = 0; /* avoid compiler stupidity */
const char *candidate = main_cmds.names[i]->name;
/*
* An exact match means we have the command, but
* for some reason exec'ing it gave us ENOENT; probably
* it's a bad interpreter in the #! line.
*/
if (!strcmp(candidate, cmd))
die(_(bad_interpreter_advice), cmd, cmd);
/* Does the candidate appear in common_cmds list? */
while (n < ARRAY_SIZE(common_cmds) &&
(cmp = strcmp(common_cmds[n].name, candidate)) < 0)
n++;
if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
/* Yes, this is one of the common commands */
n++; /* use the entry from common_cmds[] */
if (!prefixcmp(candidate, cmd)) {
/* Give prefix match a very good score */
main_cmds.names[i]->len = 0;
continue;
}
}
main_cmds.names[i]->len =
levenshtein(cmd, candidate, 0, 2, 1, 4) + 1;
}
qsort(main_cmds.names, main_cmds.cnt,
sizeof(*main_cmds.names), levenshtein_compare);
if (!main_cmds.cnt)
die ("Uh oh. Your system reports no Git commands at all.");
/* skip and count prefix matches */
for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
; /* still counting */
if (main_cmds.cnt <= n) {
/* prefix matches with everything? that is too ambiguous */
best_similarity = SIMILARITY_FLOOR + 1;
} else {
/* count all the most similar ones */
for (best_similarity = main_cmds.names[n++]->len;
(n < main_cmds.cnt &&
best_similarity == main_cmds.names[n]->len);
n++)
; /* still counting */
}
if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
const char *assumed = main_cmds.names[0]->name;
main_cmds.names[0] = NULL;
clean_cmdnames(&main_cmds);
fprintf(stderr, "WARNING: You called a Git command named '%s', "
"which does not exist.\n"
"Continuing under the assumption that you meant '%s'\n",
cmd, assumed);
if (autocorrect > 0) {
fprintf(stderr, "in %0.1f seconds automatically...\n",
(float)autocorrect/10.0);
poll(NULL, 0, autocorrect * 100);
}
return assumed;
}
fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);
if (SIMILAR_ENOUGH(best_similarity)) {
fprintf(stderr, "\nDid you mean %s?\n",
n < 2 ? "this": "one of these");
for (i = 0; i < n; i++)
fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
}
exit(1);
}
int cmd_version(int argc, const char **argv, const char *prefix)
{
printf("git version %s\n", git_version_string);
return 0;
}