Recent MinGW has a C99 implementation of snprintf functions
[git/dscho.git] / help.c
blob7f4928e45954465d0401964289952aec4bd59e2a
1 #include "cache.h"
2 #include "builtin.h"
3 #include "exec_cmd.h"
4 #include "levenshtein.h"
5 #include "help.h"
7 /* most GUI terminals set COLUMNS (although some don't export it) */
8 static int term_columns(void)
10         char *col_string = getenv("COLUMNS");
11         int n_cols;
13         if (col_string && (n_cols = atoi(col_string)) > 0)
14                 return n_cols;
16 #ifdef TIOCGWINSZ
17         {
18                 struct winsize ws;
19                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
20                         if (ws.ws_col)
21                                 return ws.ws_col;
22                 }
23         }
24 #endif
26         return 80;
29 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
31         struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
33         ent->len = len;
34         memcpy(ent->name, name, len);
35         ent->name[len] = 0;
37         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
38         cmds->names[cmds->cnt++] = ent;
41 static void clean_cmdnames(struct cmdnames *cmds)
43         int i;
44         for (i = 0; i < cmds->cnt; ++i)
45                 free(cmds->names[i]);
46         free(cmds->names);
47         cmds->cnt = 0;
48         cmds->alloc = 0;
51 static int cmdname_compare(const void *a_, const void *b_)
53         struct cmdname *a = *(struct cmdname **)a_;
54         struct cmdname *b = *(struct cmdname **)b_;
55         return strcmp(a->name, b->name);
58 static void uniq(struct cmdnames *cmds)
60         int i, j;
62         if (!cmds->cnt)
63                 return;
65         for (i = j = 1; i < cmds->cnt; i++)
66                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
67                         cmds->names[j++] = cmds->names[i];
69         cmds->cnt = j;
72 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
74         int ci, cj, ei;
75         int cmp;
77         ci = cj = ei = 0;
78         while (ci < cmds->cnt && ei < excludes->cnt) {
79                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
80                 if (cmp < 0)
81                         cmds->names[cj++] = cmds->names[ci++];
82                 else if (cmp == 0)
83                         ci++, ei++;
84                 else if (cmp > 0)
85                         ei++;
86         }
88         while (ci < cmds->cnt)
89                 cmds->names[cj++] = cmds->names[ci++];
91         cmds->cnt = cj;
94 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
96         int cols = 1, rows;
97         int space = longest + 1; /* min 1 SP between words */
98         int max_cols = term_columns() - 1; /* don't print *on* the edge */
99         int i, j;
101         if (space < max_cols)
102                 cols = max_cols / space;
103         rows = DIV_ROUND_UP(cmds->cnt, cols);
105         for (i = 0; i < rows; i++) {
106                 printf("  ");
108                 for (j = 0; j < cols; j++) {
109                         int n = j * rows + i;
110                         int size = space;
111                         if (n >= cmds->cnt)
112                                 break;
113                         if (j == cols-1 || n + rows >= cmds->cnt)
114                                 size = 1;
115                         printf("%-*s", size, cmds->names[n]->name);
116                 }
117                 putchar('\n');
118         }
121 static int is_executable(const char *name)
123         struct stat st;
125         if (stat(name, &st) || /* stat, not lstat */
126             !S_ISREG(st.st_mode))
127                 return 0;
129 #ifdef WIN32
130 {       /* cannot trust the executable bit, peek into the file instead */
131         char buf[3] = { 0 };
132         int n;
133         int fd = open(name, O_RDONLY);
134         st.st_mode &= ~S_IXUSR;
135         if (fd >= 0) {
136                 n = read(fd, buf, 2);
137                 if (n == 2)
138                         /* DOS executables start with "MZ" */
139                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
140                                 st.st_mode |= S_IXUSR;
141                 close(fd);
142         }
144 #endif
145         return st.st_mode & S_IXUSR;
148 static void list_commands_in_dir(struct cmdnames *cmds,
149                                          const char *path,
150                                          const char *prefix)
152         int prefix_len;
153         DIR *dir = opendir(path);
154         struct dirent *de;
155         struct strbuf buf = STRBUF_INIT;
156         int len;
158         if (!dir)
159                 return;
160         if (!prefix)
161                 prefix = "git-";
162         prefix_len = strlen(prefix);
164         strbuf_addf(&buf, "%s/", path);
165         len = buf.len;
167         while ((de = readdir(dir)) != NULL) {
168                 int entlen;
170                 if (prefixcmp(de->d_name, prefix))
171                         continue;
173                 strbuf_setlen(&buf, len);
174                 strbuf_addstr(&buf, de->d_name);
175                 if (!is_executable(buf.buf))
176                         continue;
178                 entlen = strlen(de->d_name) - prefix_len;
179                 if (has_extension(de->d_name, ".exe"))
180                         entlen -= 4;
182                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
183         }
184         closedir(dir);
185         strbuf_release(&buf);
188 void load_command_list(const char *prefix,
189                 struct cmdnames *main_cmds,
190                 struct cmdnames *other_cmds)
192         const char *env_path = getenv("PATH");
193         const char *exec_path = git_exec_path();
195         if (exec_path) {
196                 list_commands_in_dir(main_cmds, exec_path, prefix);
197                 qsort(main_cmds->names, main_cmds->cnt,
198                       sizeof(*main_cmds->names), cmdname_compare);
199                 uniq(main_cmds);
200         }
202         if (env_path) {
203                 char *paths, *path, *colon;
204                 path = paths = xstrdup(env_path);
205                 while (1) {
206                         if ((colon = strchr(path, PATH_SEP)))
207                                 *colon = 0;
208                         if (!exec_path || strcmp(path, exec_path))
209                                 list_commands_in_dir(other_cmds, path, prefix);
211                         if (!colon)
212                                 break;
213                         path = colon + 1;
214                 }
215                 free(paths);
217                 qsort(other_cmds->names, other_cmds->cnt,
218                       sizeof(*other_cmds->names), cmdname_compare);
219                 uniq(other_cmds);
220         }
221         exclude_cmds(other_cmds, main_cmds);
224 void list_commands(const char *title, struct cmdnames *main_cmds,
225                    struct cmdnames *other_cmds)
227         int i, longest = 0;
229         for (i = 0; i < main_cmds->cnt; i++)
230                 if (longest < main_cmds->names[i]->len)
231                         longest = main_cmds->names[i]->len;
232         for (i = 0; i < other_cmds->cnt; i++)
233                 if (longest < other_cmds->names[i]->len)
234                         longest = other_cmds->names[i]->len;
236         if (main_cmds->cnt) {
237                 const char *exec_path = git_exec_path();
238                 printf("available %s in '%s'\n", title, exec_path);
239                 printf("----------------");
240                 mput_char('-', strlen(title) + strlen(exec_path));
241                 putchar('\n');
242                 pretty_print_string_list(main_cmds, longest);
243                 putchar('\n');
244         }
246         if (other_cmds->cnt) {
247                 printf("%s available from elsewhere on your $PATH\n", title);
248                 printf("---------------------------------------");
249                 mput_char('-', strlen(title));
250                 putchar('\n');
251                 pretty_print_string_list(other_cmds, longest);
252                 putchar('\n');
253         }
256 int is_in_cmdlist(struct cmdnames *c, const char *s)
258         int i;
259         for (i = 0; i < c->cnt; i++)
260                 if (!strcmp(s, c->names[i]->name))
261                         return 1;
262         return 0;
265 static int autocorrect;
266 static struct cmdnames aliases;
268 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
270         if (!strcmp(var, "help.autocorrect"))
271                 autocorrect = git_config_int(var,value);
272         /* Also use aliases for command lookup */
273         if (!prefixcmp(var, "alias."))
274                 add_cmdname(&aliases, var + 6, strlen(var + 6));
276         return git_default_config(var, value, cb);
279 static int levenshtein_compare(const void *p1, const void *p2)
281         const struct cmdname *const *c1 = p1, *const *c2 = p2;
282         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
283         int l1 = (*c1)->len;
284         int l2 = (*c2)->len;
285         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
288 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
290         int i;
291         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
293         for (i = 0; i < old->cnt; i++)
294                 cmds->names[cmds->cnt++] = old->names[i];
295         free(old->names);
296         old->cnt = 0;
297         old->names = NULL;
300 /* An empirically derived magic number */
301 #define SIMILAR_ENOUGH(x) ((x) < 6)
303 const char *help_unknown_cmd(const char *cmd)
305         int i, n, best_similarity = 0;
306         struct cmdnames main_cmds, other_cmds;
308         memset(&main_cmds, 0, sizeof(main_cmds));
309         memset(&other_cmds, 0, sizeof(other_cmds));
310         memset(&aliases, 0, sizeof(aliases));
312         git_config(git_unknown_cmd_config, NULL);
314         load_command_list("git-", &main_cmds, &other_cmds);
316         add_cmd_list(&main_cmds, &aliases);
317         add_cmd_list(&main_cmds, &other_cmds);
318         qsort(main_cmds.names, main_cmds.cnt,
319               sizeof(main_cmds.names), cmdname_compare);
320         uniq(&main_cmds);
322         /* This reuses cmdname->len for similarity index */
323         for (i = 0; i < main_cmds.cnt; ++i)
324                 main_cmds.names[i]->len =
325                         levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
327         qsort(main_cmds.names, main_cmds.cnt,
328               sizeof(*main_cmds.names), levenshtein_compare);
330         if (!main_cmds.cnt)
331                 die ("Uh oh. Your system reports no Git commands at all.");
333         best_similarity = main_cmds.names[0]->len;
334         n = 1;
335         while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
336                 ++n;
337         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
338                 const char *assumed = main_cmds.names[0]->name;
339                 main_cmds.names[0] = NULL;
340                 clean_cmdnames(&main_cmds);
341                 fprintf(stderr, "WARNING: You called a Git command named '%s', "
342                         "which does not exist.\n"
343                         "Continuing under the assumption that you meant '%s'\n",
344                         cmd, assumed);
345                 if (autocorrect > 0) {
346                         fprintf(stderr, "in %0.1f seconds automatically...\n",
347                                 (float)autocorrect/10.0);
348                         poll(NULL, 0, autocorrect * 100);
349                 }
350                 return assumed;
351         }
353         fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);
355         if (SIMILAR_ENOUGH(best_similarity)) {
356                 fprintf(stderr, "\nDid you mean %s?\n",
357                         n < 2 ? "this": "one of these");
359                 for (i = 0; i < n; i++)
360                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
361         }
363         exit(1);
366 int cmd_version(int argc, const char **argv, const char *prefix)
368         printf("git version %s\n", git_version_string);
369         return 0;