Work around missing hard links on FAT formatted media
[git/dscho.git] / setup.c
blobc487d7eb9de70c651ef06a6bfd4a7571337fad84
1 #include "cache.h"
3 const char *prefix_path(const char *prefix, int len, const char *path)
5 const char *orig = path;
6 for (;;) {
7 char c;
8 if (*path != '.')
9 break;
10 c = path[1];
11 /* "." */
12 if (!c) {
13 path++;
14 break;
16 /* "./" */
17 if (c == '/') {
18 path += 2;
19 continue;
21 if (c != '.')
22 break;
23 c = path[2];
24 if (!c)
25 path += 2;
26 else if (c == '/')
27 path += 3;
28 else
29 break;
30 /* ".." and "../" */
31 /* Remove last component of the prefix */
32 do {
33 if (!len)
34 die("'%s' is outside repository", orig);
35 len--;
36 } while (len && prefix[len-1] != '/');
37 continue;
39 if (len) {
40 int speclen = strlen(path);
41 char *n = xmalloc(speclen + len + 1);
43 memcpy(n, prefix, len);
44 memcpy(n + len, path, speclen+1);
45 path = n;
47 return path;
50 const char **get_pathspec(const char *prefix, const char **pathspec)
52 const char *entry = *pathspec;
53 const char **p;
54 int prefixlen;
56 if (!prefix && !entry)
57 return NULL;
59 if (!entry) {
60 static const char *spec[2];
61 spec[0] = prefix;
62 spec[1] = NULL;
63 return spec;
66 /* Otherwise we have to re-write the entries.. */
67 p = pathspec;
68 prefixlen = prefix ? strlen(prefix) : 0;
69 do {
70 *p = prefix_path(prefix, prefixlen, entry);
71 } while ((entry = *++p) != NULL);
72 return (const char **) pathspec;
76 * Test it it looks like we're at the top
77 * level git directory. We want to see a
79 * - either a .git/objects/ directory _or_ the proper
80 * GIT_OBJECT_DIRECTORY environment variable
81 * - a refs/ directory under ".git"
82 * - either a HEAD symlink or a HEAD file that is formatted as
83 * a proper "ref:".
85 static int is_toplevel_directory(void)
87 if (access(".git/refs/", X_OK) ||
88 access(getenv(DB_ENVIRONMENT) ?
89 getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
90 validate_symref(".git/HEAD"))
91 return 0;
92 return 1;
95 const char *setup_git_directory(void)
97 static char cwd[PATH_MAX+1];
98 int len, offset;
101 * If GIT_DIR is set explicitly, we're not going
102 * to do any discovery
104 if (getenv(GIT_DIR_ENVIRONMENT))
105 return NULL;
107 if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
108 die("Unable to read current working directory");
110 offset = len = strlen(cwd);
111 for (;;) {
112 if (is_toplevel_directory())
113 break;
114 chdir("..");
115 do {
116 if (!offset)
117 die("Not a git repository");
118 } while (cwd[--offset] != '/');
121 if (offset == len)
122 return NULL;
124 /* Make "offset" point to past the '/', and add a '/' at the end */
125 offset++;
126 cwd[len++] = '/';
127 cwd[len] = 0;
128 return cwd + offset;