Documentation: add a new man page for "git-help"
[git/git.git] / help.c
CommitLineData
70827b15
LT
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"
70827b15 10
82e5a82f 11/* most GUI terminals set COLUMNS (although some don't export it) */
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12static int term_columns(void)
13{
14 char *col_string = getenv("COLUMNS");
96f1e58f 15 int n_cols;
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16
17 if (col_string && (n_cols = atoi(col_string)) > 0)
18 return n_cols;
19
20#ifdef TIOCGWINSZ
21 {
22 struct winsize ws;
23 if (!ioctl(1, TIOCGWINSZ, &ws)) {
24 if (ws.ws_col)
25 return ws.ws_col;
26 }
27 }
28#endif
29
30 return 80;
31}
32
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33static inline void mput_char(char c, unsigned int num)
34{
35 while(num--)
36 putchar(c);
37}
38
1eb05690
SP
39static struct cmdnames {
40 int alloc;
41 int cnt;
42 struct cmdname {
43 size_t len;
44 char name[1];
45 } **names;
46} main_cmds, other_cmds;
47
48static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
70827b15 49{
1eb05690
SP
50 struct cmdname *ent = xmalloc(sizeof(*ent) + len);
51
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52 ent->len = len;
53 memcpy(ent->name, name, len);
54 ent->name[len] = 0;
1eb05690
SP
55
56 ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
57 cmds->names[cmds->cnt++] = ent;
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58}
59
60static int cmdname_compare(const void *a_, const void *b_)
61{
62 struct cmdname *a = *(struct cmdname **)a_;
63 struct cmdname *b = *(struct cmdname **)b_;
64 return strcmp(a->name, b->name);
65}
66
1eb05690
SP
67static void uniq(struct cmdnames *cmds)
68{
69 int i, j;
70
71 if (!cmds->cnt)
72 return;
73
74 for (i = j = 1; i < cmds->cnt; i++)
75 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
76 cmds->names[j++] = cmds->names[i];
77
78 cmds->cnt = j;
79}
80
f3fa1838
JH
81static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
82{
1eb05690
SP
83 int ci, cj, ei;
84 int cmp;
85
86 ci = cj = ei = 0;
87 while (ci < cmds->cnt && ei < excludes->cnt) {
88 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
89 if (cmp < 0)
90 cmds->names[cj++] = cmds->names[ci++];
91 else if (cmp == 0)
92 ci++, ei++;
93 else if (cmp > 0)
94 ei++;
95 }
96
97 while (ci < cmds->cnt)
98 cmds->names[cj++] = cmds->names[ci++];
99
100 cmds->cnt = cj;
101}
102
103static void pretty_print_string_list(struct cmdnames *cmds, int longest)
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104{
105 int cols = 1, rows;
106 int space = longest + 1; /* min 1 SP between words */
107 int max_cols = term_columns() - 1; /* don't print *on* the edge */
108 int i, j;
109
110 if (space < max_cols)
111 cols = max_cols / space;
1eb05690 112 rows = (cmds->cnt + cols - 1) / cols;
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LT
113
114 for (i = 0; i < rows; i++) {
115 printf(" ");
116
117 for (j = 0; j < cols; j++) {
118 int n = j * rows + i;
119 int size = space;
1eb05690 120 if (n >= cmds->cnt)
70827b15 121 break;
1eb05690 122 if (j == cols-1 || n + rows >= cmds->cnt)
70827b15 123 size = 1;
1eb05690 124 printf("%-*s", size, cmds->names[n]->name);
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LT
125 }
126 putchar('\n');
127 }
128}
129
1eb05690
SP
130static unsigned int list_commands_in_dir(struct cmdnames *cmds,
131 const char *path)
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132{
133 unsigned int longest = 0;
edb6ddc5
SP
134 const char *prefix = "git-";
135 int prefix_len = strlen(prefix);
1eb05690 136 DIR *dir = opendir(path);
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137 struct dirent *de;
138
1eb05690
SP
139 if (!dir || chdir(path))
140 return 0;
70827b15 141
70827b15
LT
142 while ((de = readdir(dir)) != NULL) {
143 struct stat st;
144 int entlen;
145
edb6ddc5 146 if (prefixcmp(de->d_name, prefix))
70827b15 147 continue;
0966003c
SP
148
149 if (stat(de->d_name, &st) || /* stat, not lstat */
70827b15
LT
150 !S_ISREG(st.st_mode) ||
151 !(st.st_mode & S_IXUSR))
152 continue;
153
edb6ddc5 154 entlen = strlen(de->d_name) - prefix_len;
5bb1cda5 155 if (has_extension(de->d_name, ".exe"))
70827b15
LT
156 entlen -= 4;
157
158 if (longest < entlen)
159 longest = entlen;
160
1eb05690 161 add_cmdname(cmds, de->d_name + prefix_len, entlen);
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LT
162 }
163 closedir(dir);
164
1eb05690
SP
165 return longest;
166}
167
168static void list_commands(void)
169{
170 unsigned int longest = 0;
171 unsigned int len;
172 const char *env_path = getenv("PATH");
173 char *paths, *path, *colon;
174 const char *exec_path = git_exec_path();
175
176 if (exec_path)
177 longest = list_commands_in_dir(&main_cmds, exec_path);
178
179 if (!env_path) {
180 fprintf(stderr, "PATH not set\n");
181 exit(1);
182 }
183
184 path = paths = xstrdup(env_path);
185 while (1) {
186 if ((colon = strchr(path, ':')))
187 *colon = 0;
188
189 len = list_commands_in_dir(&other_cmds, path);
190 if (len > longest)
191 longest = len;
192
193 if (!colon)
194 break;
195 path = colon + 1;
196 }
197 free(paths);
198
199 qsort(main_cmds.names, main_cmds.cnt,
200 sizeof(*main_cmds.names), cmdname_compare);
201 uniq(&main_cmds);
202
203 qsort(other_cmds.names, other_cmds.cnt,
204 sizeof(*other_cmds.names), cmdname_compare);
205 uniq(&other_cmds);
206 exclude_cmds(&other_cmds, &main_cmds);
207
208 if (main_cmds.cnt) {
209 printf("available git commands in '%s'\n", exec_path);
210 printf("----------------------------");
211 mput_char('-', strlen(exec_path));
212 putchar('\n');
213 pretty_print_string_list(&main_cmds, longest);
214 putchar('\n');
215 }
216
217 if (other_cmds.cnt) {
218 printf("git commands available from elsewhere on your $PATH\n");
219 printf("---------------------------------------------------\n");
220 pretty_print_string_list(&other_cmds, longest);
221 putchar('\n');
222 }
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223}
224
3d7e2d85 225void list_common_cmds_help(void)
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226{
227 int i, longest = 0;
228
229 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
230 if (longest < strlen(common_cmds[i].name))
231 longest = strlen(common_cmds[i].name);
232 }
233
234 puts("The most commonly used git commands are:");
235 for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
4f75b115
RS
236 printf(" %s ", common_cmds[i].name);
237 mput_char(' ', longest - strlen(common_cmds[i].name));
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LT
238 puts(common_cmds[i].help);
239 }
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LT
240}
241
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242static void show_man_page(const char *git_cmd)
243{
244 const char *page;
245
cc44c765 246 if (!prefixcmp(git_cmd, "git"))
70827b15
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247 page = git_cmd;
248 else {
249 int page_len = strlen(git_cmd) + 4;
2d7320d0 250 char *p = xmalloc(page_len + 1);
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LT
251 strcpy(p, "git-");
252 strcpy(p + 4, git_cmd);
253 p[page_len] = 0;
254 page = p;
255 }
256
257 execlp("man", "man", page, NULL);
258}
259
822a7d50
RJ
260void help_unknown_cmd(const char *cmd)
261{
a238917b 262 fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
822a7d50
RJ
263 exit(1);
264}
265
a633fca0 266int cmd_version(int argc, const char **argv, const char *prefix)
70827b15
LT
267{
268 printf("git version %s\n", git_version_string);
269 return 0;
270}
271
a633fca0 272int cmd_help(int argc, const char **argv, const char *prefix)
70827b15 273{
6acbcb92 274 const char *help_cmd = argc > 1 ? argv[1] : NULL;
822a7d50
RJ
275
276 if (!help_cmd) {
277 printf("usage: %s\n\n", git_usage_string);
278 list_common_cmds_help();
3d7e2d85 279 exit(0);
822a7d50
RJ
280 }
281
282 else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
283 printf("usage: %s\n\n", git_usage_string);
1eb05690 284 list_commands();
3d7e2d85 285 exit(0);
822a7d50
RJ
286 }
287
70827b15
LT
288 else
289 show_man_page(help_cmd);
822a7d50 290
70827b15
LT
291 return 0;
292}