Fix bug introduced by the latest changes to git-pack-redundant
[git.git] / git.c
1 #include <stdio.h>
2 #include <sys/types.h>
3 #include <sys/stat.h>
4 #include <dirent.h>
5 #include <unistd.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <errno.h>
9 #include <limits.h>
10 #include <stdarg.h>
11
12 #ifndef PATH_MAX
13 # define PATH_MAX 4096
14 #endif
15
16 static const char git_usage[] =
17         "Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
18
19 /* most gui terms set COLUMNS (although some don't export it) */
20 static int term_columns(void)
21 {
22         char *col_string = getenv("COLUMNS");
23         int n_cols = 0;
24
25         if (col_string && (n_cols = atoi(col_string)) > 0)
26                 return n_cols;
27
28         return 80;
29 }
30
31 static void oom(void)
32 {
33         fprintf(stderr, "git: out of memory\n");
34         exit(1);
35 }
36
37 static inline void mput_char(char c, unsigned int num)
38 {
39         while(num--)
40                 putchar(c);
41 }
42
43 static struct cmdname {
44         size_t len;
45         char name[1];
46 } **cmdname;
47 static int cmdname_alloc, cmdname_cnt;
48
49 static void add_cmdname(const char *name, int len)
50 {
51         struct cmdname *ent;
52         if (cmdname_alloc <= cmdname_cnt) {
53                 cmdname_alloc = cmdname_alloc + 200;
54                 cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
55                 if (!cmdname)
56                         oom();
57         }
58         ent = malloc(sizeof(*ent) + len);
59         if (!ent)
60                 oom();
61         ent->len = len;
62         memcpy(ent->name, name, len+1);
63         cmdname[cmdname_cnt++] = ent;
64 }
65
66 static int cmdname_compare(const void *a_, const void *b_)
67 {
68         struct cmdname *a = *(struct cmdname **)a_;
69         struct cmdname *b = *(struct cmdname **)b_;
70         return strcmp(a->name, b->name);
71 }
72
73 static void pretty_print_string_list(struct cmdname **cmdname, int longest)
74 {
75         int cols = 1;
76         int space = longest + 1; /* min 1 SP between words */
77         int max_cols = term_columns() - 1; /* don't print *on* the edge */
78         int i;
79
80         if (space < max_cols)
81                 cols = max_cols / space;
82
83         qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
84
85         for (i = 0; i < cmdname_cnt; ) {
86                 int c;
87                 printf("  ");
88
89                 for (c = cols; c && i < cmdname_cnt; i++) {
90                         printf("%s", cmdname[i]->name);
91
92                         if (--c)
93                                 mput_char(' ', space - cmdname[i]->len);
94                 }
95                 putchar('\n');
96         }
97 }
98
99 static void list_commands(const char *exec_path, const char *pattern)
100 {
101         unsigned int longest = 0;
102         char path[PATH_MAX];
103         int dirlen;
104         DIR *dir = opendir(exec_path);
105         struct dirent *de;
106
107         if (!dir) {
108                 fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
109                 exit(1);
110         }
111
112         dirlen = strlen(exec_path);
113         if (PATH_MAX - 20 < dirlen) {
114                 fprintf(stderr, "git: insanely long exec-path '%s'\n",
115                         exec_path);
116                 exit(1);
117         }
118
119         memcpy(path, exec_path, dirlen);
120         path[dirlen++] = '/';
121
122         while ((de = readdir(dir)) != NULL) {
123                 struct stat st;
124                 int entlen;
125
126                 if (strncmp(de->d_name, "git-", 4))
127                         continue;
128                 strcpy(path+dirlen, de->d_name);
129                 if (stat(path, &st) || /* stat, not lstat */
130                     !S_ISREG(st.st_mode) ||
131                     !(st.st_mode & S_IXUSR))
132                         continue;
133
134                 entlen = strlen(de->d_name);
135
136                 if (longest < entlen)
137                         longest = entlen;
138
139                 add_cmdname(de->d_name + 4, entlen-4);
140         }
141         closedir(dir);
142
143         printf("git commands available in '%s'\n", exec_path);
144         printf("----------------------------");
145         mput_char('-', strlen(exec_path));
146         putchar('\n');
147         pretty_print_string_list(cmdname, longest - 4);
148         putchar('\n');
149 }
150
151 #ifdef __GNUC__
152 static void usage(const char *exec_path, const char *fmt, ...)
153         __attribute__((__format__(__printf__, 2, 3), __noreturn__));
154 #endif
155 static void usage(const char *exec_path, const char *fmt, ...)
156 {
157         if (fmt) {
158                 va_list ap;
159
160                 va_start(ap, fmt);
161                 printf("git: ");
162                 vprintf(fmt, ap);
163                 va_end(ap);
164                 putchar('\n');
165         }
166         else
167                 puts(git_usage);
168
169         putchar('\n');
170
171         if(exec_path)
172                 list_commands(exec_path, "git-*");
173
174         exit(1);
175 }
176
177 static void prepend_to_path(const char *dir, int len)
178 {
179         char *path, *old_path = getenv("PATH");
180         int path_len = len;
181
182         if (!old_path)
183                 old_path = "/usr/local/bin:/usr/bin:/bin";
184
185         path_len = len + strlen(old_path) + 1;
186
187         path = malloc(path_len + 1);
188         path[path_len + 1] = '\0';
189
190         memcpy(path, dir, len);
191         path[len] = ':';
192         memcpy(path + len + 1, old_path, path_len - len);
193
194         setenv("PATH", path, 1);
195 }
196
197 static void show_man_page(char *git_cmd)
198 {
199         char *page;
200
201         if (!strncmp(git_cmd, "git", 3))
202                 page = git_cmd;
203         else {
204                 int page_len = strlen(git_cmd) + 4;
205
206                 page = malloc(page_len + 1);
207                 strcpy(page, "git-");
208                 strcpy(page + 4, git_cmd);
209                 page[page_len] = 0;
210         }
211
212         execlp("man", "man", page, NULL);
213 }
214
215 int main(int argc, char **argv, char **envp)
216 {
217         char git_command[PATH_MAX + 1];
218         char wd[PATH_MAX + 1];
219         int i, len, show_help = 0;
220         char *exec_path = getenv("GIT_EXEC_PATH");
221
222         getcwd(wd, PATH_MAX);
223
224         if (!exec_path)
225                 exec_path = GIT_EXEC_PATH;
226
227         for (i = 1; i < argc; i++) {
228                 char *arg = argv[i];
229
230                 if (strncmp(arg, "--", 2))
231                         break;
232
233                 arg += 2;
234
235                 if (!strncmp(arg, "exec-path", 9)) {
236                         arg += 9;
237                         if (*arg == '=')
238                                 exec_path = arg + 1;
239                         else {
240                                 puts(exec_path);
241                                 exit(0);
242                         }
243                 }
244                 else if (!strcmp(arg, "version")) {
245                         printf("git version %s\n", GIT_VERSION);
246                         exit(0);
247                 }
248                 else if (!strcmp(arg, "help"))
249                         show_help = 1;
250                 else if (!show_help)
251                         usage(NULL, NULL);
252         }
253
254         if (i >= argc || show_help) {
255                 if (i >= argc)
256                         usage(exec_path, NULL);
257
258                 show_man_page(argv[i]);
259         }
260
261         if (*exec_path != '/') {
262                 if (!getcwd(git_command, sizeof(git_command))) {
263                         fprintf(stderr,
264                                 "git: cannot determine current directory");
265                         exit(1);
266                 }
267                 len = strlen(git_command);
268
269                 /* Trivial cleanup */
270                 while (!strncmp(exec_path, "./", 2)) {
271                         exec_path += 2;
272                         while (*exec_path == '/')
273                                 *exec_path++;
274                 }
275                 snprintf(git_command + len, sizeof(git_command) - len,
276                          "/%s", exec_path);
277         }
278         else
279                 strcpy(git_command, exec_path);
280         len = strlen(git_command);
281         prepend_to_path(git_command, len);
282
283         strncat(&git_command[len], "/git-", sizeof(git_command) - len);
284         len += 5;
285         strncat(&git_command[len], argv[i], sizeof(git_command) - len);
286
287         if (access(git_command, X_OK))
288                 usage(exec_path, "'%s' is not a git-command", argv[i]);
289
290         /* execve() can only ever return if it fails */
291         execve(git_command, &argv[i], envp);
292         printf("Failed to run command '%s': %s\n", git_command, strerror(errno));
293
294         return 1;
295 }