Style: place opening brace of a function definition at column 1
[git/git.git] / help.c
1 /*
2 * builtin-help.c
3 *
4 * Builtin help-related commands (help, usage, version)
5 */
6 #include "cache.h"
7 #include "builtin.h"
8 #include "exec_cmd.h"
9 #include "common-cmds.h"
10 #include <sys/ioctl.h>
11
12 /* most GUI terminals set COLUMNS (although some don't export it) */
13 static int term_columns(void)
14 {
15 char *col_string = getenv("COLUMNS");
16 int n_cols;
17
18 if (col_string && (n_cols = atoi(col_string)) > 0)
19 return n_cols;
20
21 #ifdef TIOCGWINSZ
22 {
23 struct winsize ws;
24 if (!ioctl(1, TIOCGWINSZ, &ws)) {
25 if (ws.ws_col)
26 return ws.ws_col;
27 }
28 }
29 #endif
30
31 return 80;
32 }
33
34 static inline void mput_char(char c, unsigned int num)
35 {
36 while(num--)
37 putchar(c);
38 }
39
40 static struct cmdnames {
41 int alloc;
42 int cnt;
43 struct cmdname {
44 size_t len;
45 char name[1];
46 } **names;
47 } main_cmds, other_cmds;
48
49 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
50 {
51 struct cmdname *ent = xmalloc(sizeof(*ent) + len);
52
53 ent->len = len;
54 memcpy(ent->name, name, len);
55 ent->name[len] = 0;
56
57 ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
58 cmds->names[cmds->cnt++] = ent;
59 }
60
61 static int cmdname_compare(const void *a_, const void *b_)
62 {
63 struct cmdname *a = *(struct cmdname **)a_;
64 struct cmdname *b = *(struct cmdname **)b_;
65 return strcmp(a->name, b->name);
66 }
67
68 static void uniq(struct cmdnames *cmds)
69 {
70 int i, j;
71
72 if (!cmds->cnt)
73 return;
74
75 for (i = j = 1; i < cmds->cnt; i++)
76 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
77 cmds->names[j++] = cmds->names[i];
78
79 cmds->cnt = j;
80 }
81
82 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
83 {
84 int ci, cj, ei;
85 int cmp;
86
87 ci = cj = ei = 0;
88 while (ci < cmds->cnt && ei < excludes->cnt) {
89 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
90 if (cmp < 0)
91 cmds->names[cj++] = cmds->names[ci++];
92 else if (cmp == 0)
93 ci++, ei++;
94 else if (cmp > 0)
95 ei++;
96 }
97
98 while (ci < cmds->cnt)
99 cmds->names[cj++] = cmds->names[ci++];
100
101 cmds->cnt = cj;
102 }
103
104 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
105 {
106 int cols = 1, rows;
107 int space = longest + 1; /* min 1 SP between words */
108 int max_cols = term_columns() - 1; /* don't print *on* the edge */
109 int i, j;
110
111 if (space < max_cols)
112 cols = max_cols / space;
113 rows = (cmds->cnt + cols - 1) / cols;
114
115 for (i = 0; i < rows; i++) {
116 printf(" ");
117
118 for (j = 0; j < cols; j++) {
119 int n = j * rows + i;
120 int size = space;
121 if (n >= cmds->cnt)
122 break;
123 if (j == cols-1 || n + rows >= cmds->cnt)
124 size = 1;
125 printf("%-*s", size, cmds->names[n]->name);
126 }
127 putchar('\n');
128 }
129 }
130
131 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
132 const char *path)
133 {
134 unsigned int longest = 0;
135 const char *prefix = "git-";
136 int prefix_len = strlen(prefix);
137 DIR *dir = opendir(path);
138 struct dirent *de;
139
140 if (!dir || chdir(path))
141 return 0;
142
143 while ((de = readdir(dir)) != NULL) {
144 struct stat st;
145 int entlen;
146
147 if (prefixcmp(de->d_name, prefix))
148 continue;
149
150 if (stat(de->d_name, &st) || /* stat, not lstat */
151 !S_ISREG(st.st_mode) ||
152 !(st.st_mode & S_IXUSR))
153 continue;
154
155 entlen = strlen(de->d_name) - prefix_len;
156 if (has_extension(de->d_name, ".exe"))
157 entlen -= 4;
158
159 if (longest < entlen)
160 longest = entlen;
161
162 add_cmdname(cmds, de->d_name + prefix_len, entlen);
163 }
164 closedir(dir);
165
166 return longest;
167 }
168
169 static void list_commands(void)
170 {
171 unsigned int longest = 0;
172 unsigned int len;
173 const char *env_path = getenv("PATH");
174 char *paths, *path, *colon;
175 const char *exec_path = git_exec_path();
176
177 if (exec_path)
178 longest = list_commands_in_dir(&main_cmds, exec_path);
179
180 if (!env_path) {
181 fprintf(stderr, "PATH not set\n");
182 exit(1);
183 }
184
185 path = paths = xstrdup(env_path);
186 while (1) {
187 if ((colon = strchr(path, ':')))
188 *colon = 0;
189
190 len = list_commands_in_dir(&other_cmds, path);
191 if (len > longest)
192 longest = len;
193
194 if (!colon)
195 break;
196 path = colon + 1;
197 }
198 free(paths);
199
200 qsort(main_cmds.names, main_cmds.cnt,
201 sizeof(*main_cmds.names), cmdname_compare);
202 uniq(&main_cmds);
203
204 qsort(other_cmds.names, other_cmds.cnt,
205 sizeof(*other_cmds.names), cmdname_compare);
206 uniq(&other_cmds);
207 exclude_cmds(&other_cmds, &main_cmds);
208
209 if (main_cmds.cnt) {
210 printf("available git commands in '%s'\n", exec_path);
211 printf("----------------------------");
212 mput_char('-', strlen(exec_path));
213 putchar('\n');
214 pretty_print_string_list(&main_cmds, longest);
215 putchar('\n');
216 }
217
218 if (other_cmds.cnt) {
219 printf("git commands available from elsewhere on your $PATH\n");
220 printf("---------------------------------------------------\n");
221 pretty_print_string_list(&other_cmds, longest);
222 putchar('\n');
223 }
224 }
225
226 void list_common_cmds_help(void)
227 {
228 int i, longest = 0;
229
230 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
231 if (longest < strlen(common_cmds[i].name))
232 longest = strlen(common_cmds[i].name);
233 }
234
235 puts("The most commonly used git commands are:");
236 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
237 printf(" %s ", common_cmds[i].name);
238 mput_char(' ', longest - strlen(common_cmds[i].name));
239 puts(common_cmds[i].help);
240 }
241 puts("(use 'git help -a' to get a list of all installed git commands)");
242 }
243
244 static void show_man_page(const char *git_cmd)
245 {
246 const char *page;
247
248 if (!prefixcmp(git_cmd, "git"))
249 page = git_cmd;
250 else {
251 int page_len = strlen(git_cmd) + 4;
252 char *p = xmalloc(page_len + 1);
253 strcpy(p, "git-");
254 strcpy(p + 4, git_cmd);
255 p[page_len] = 0;
256 page = p;
257 }
258
259 execlp("man", "man", page, NULL);
260 }
261
262 void help_unknown_cmd(const char *cmd)
263 {
264 fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
265 exit(1);
266 }
267
268 int cmd_version(int argc, const char **argv, const char *prefix)
269 {
270 printf("git version %s\n", git_version_string);
271 return 0;
272 }
273
274 int cmd_help(int argc, const char **argv, const char *prefix)
275 {
276 const char *help_cmd = argc > 1 ? argv[1] : NULL;
277
278 if (!help_cmd) {
279 printf("usage: %s\n\n", git_usage_string);
280 list_common_cmds_help();
281 exit(0);
282 }
283
284 else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
285 printf("usage: %s\n\n", git_usage_string);
286 list_commands();
287 exit(0);
288 }
289
290 else
291 show_man_page(help_cmd);
292
293 return 0;
294 }