short i/o: clean up the naming for the write_{in,or}_xxx family
[git/git.git] / path.c
CommitLineData
26c8a533
LT
1/*
2 * I'm tired of doing "vsnprintf()" etc just to open a
3 * file, so here's a "return static buffer with printf"
4 * interface for paths.
5 *
6 * It's obviously not thread-safe. Sue me. But it's quite
7 * useful for doing things like
8 *
9 * f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
10 *
11 * which is what it's designed for.
12 */
13#include "cache.h"
14
26c8a533
LT
15static char bad_path[] = "/bad-path/";
16
e7676d2f
LT
17static char *get_pathname(void)
18{
19 static char pathname_array[4][PATH_MAX];
20 static int index;
21 return pathname_array[3 & ++index];
22}
23
26c8a533
LT
24static char *cleanup_path(char *path)
25{
26 /* Clean it up */
27 if (!memcmp(path, "./", 2)) {
28 path += 2;
29 while (*path == '/')
30 path++;
31 }
32 return path;
33}
34
35char *mkpath(const char *fmt, ...)
36{
37 va_list args;
38 unsigned len;
e7676d2f 39 char *pathname = get_pathname();
26c8a533
LT
40
41 va_start(args, fmt);
42 len = vsnprintf(pathname, PATH_MAX, fmt, args);
43 va_end(args);
44 if (len >= PATH_MAX)
45 return bad_path;
46 return cleanup_path(pathname);
47}
48
49char *git_path(const char *fmt, ...)
50{
5da1606d 51 const char *git_dir = get_git_dir();
e7676d2f 52 char *pathname = get_pathname();
26c8a533
LT
53 va_list args;
54 unsigned len;
55
56 len = strlen(git_dir);
57 if (len > PATH_MAX-100)
58 return bad_path;
59 memcpy(pathname, git_dir, len);
60 if (len && git_dir[len-1] != '/')
61 pathname[len++] = '/';
62 va_start(args, fmt);
63 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
64 va_end(args);
65 if (len >= PATH_MAX)
66 return bad_path;
67 return cleanup_path(pathname);
68}
f2db68ed
HE
69
70
71/* git_mkstemp() - create tmp file honoring TMPDIR variable */
72int git_mkstemp(char *path, size_t len, const char *template)
73{
74 char *env, *pch = path;
75
76 if ((env = getenv("TMPDIR")) == NULL) {
77 strcpy(pch, "/tmp/");
78 len -= 5;
35c3c629
HE
79 pch += 5;
80 } else {
81 size_t n = snprintf(pch, len, "%s/", env);
82
83 len -= n;
84 pch += n;
85 }
f2db68ed 86
817151e6 87 strlcpy(pch, template, len);
f2db68ed
HE
88
89 return mkstemp(path);
90}
91
92
0870ca7f
JH
93int validate_symref(const char *path)
94{
95 struct stat st;
96 char *buf, buffer[256];
97 int len, fd;
98
99 if (lstat(path, &st) < 0)
100 return -1;
101
102 /* Make sure it is a "refs/.." symlink */
103 if (S_ISLNK(st.st_mode)) {
104 len = readlink(path, buffer, sizeof(buffer)-1);
105 if (len >= 5 && !memcmp("refs/", buffer, 5))
106 return 0;
107 return -1;
108 }
109
110 /*
111 * Anything else, just open it and try to see if it is a symbolic ref.
112 */
113 fd = open(path, O_RDONLY);
114 if (fd < 0)
115 return -1;
116 len = read(fd, buffer, sizeof(buffer)-1);
117 close(fd);
118
119 /*
120 * Is it a symbolic ref?
121 */
122 if (len < 4 || memcmp("ref:", buffer, 4))
123 return -1;
124 buf = buffer + 4;
125 len -= 4;
126 while (len && isspace(*buf))
127 buf++, len--;
128 if (len >= 5 && !memcmp("refs/", buf, 5))
129 return 0;
130 return -1;
131}
132
d79374c7 133static char *user_path(char *buf, char *path, int sz)
54f4b874 134{
d79374c7
JH
135 struct passwd *pw;
136 char *slash;
137 int len, baselen;
54f4b874 138
d79374c7
JH
139 if (!path || path[0] != '~')
140 return NULL;
141 path++;
142 slash = strchr(path, '/');
143 if (path[0] == '/' || !path[0]) {
144 pw = getpwuid(getuid());
145 }
146 else {
147 if (slash) {
148 *slash = 0;
149 pw = getpwnam(path);
150 *slash = '/';
54f4b874 151 }
d79374c7
JH
152 else
153 pw = getpwnam(path);
54f4b874 154 }
d79374c7
JH
155 if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
156 return NULL;
157 baselen = strlen(pw->pw_dir);
158 memcpy(buf, pw->pw_dir, baselen);
159 while ((1 < baselen) && (buf[baselen-1] == '/')) {
160 buf[baselen-1] = 0;
161 baselen--;
162 }
163 if (slash && slash[1]) {
164 len = strlen(slash);
165 if (sz <= baselen + len)
166 return NULL;
167 memcpy(buf + baselen, slash, len + 1);
168 }
169 return buf;
54f4b874
AE
170}
171
d79374c7
JH
172/*
173 * First, one directory to try is determined by the following algorithm.
174 *
175 * (0) If "strict" is given, the path is used as given and no DWIM is
176 * done. Otherwise:
177 * (1) "~/path" to mean path under the running user's home directory;
178 * (2) "~user/path" to mean path under named user's home directory;
179 * (3) "relative/path" to mean cwd relative directory; or
180 * (4) "/absolute/path" to mean absolute directory.
181 *
182 * Unless "strict" is given, we try access() for existence of "%s.git/.git",
183 * "%s/.git", "%s.git", "%s" in this order. The first one that exists is
184 * what we try.
185 *
186 * Second, we try chdir() to that. Upon failure, we return NULL.
187 *
188 * Then, we try if the current directory is a valid git repository.
189 * Upon failure, we return NULL.
190 *
191 * If all goes well, we return the directory we used to chdir() (but
192 * before ~user is expanded), avoiding getcwd() resolving symbolic
193 * links. User relative paths are also returned as they are given,
194 * except DWIM suffixing.
195 */
54f4b874
AE
196char *enter_repo(char *path, int strict)
197{
d79374c7
JH
198 static char used_path[PATH_MAX];
199 static char validated_path[PATH_MAX];
200
201 if (!path)
54f4b874
AE
202 return NULL;
203
d79374c7
JH
204 if (!strict) {
205 static const char *suffix[] = {
206 ".git/.git", "/.git", ".git", "", NULL,
207 };
208 int len = strlen(path);
209 int i;
210 while ((1 < len) && (path[len-1] == '/')) {
211 path[len-1] = 0;
212 len--;
213 }
214 if (PATH_MAX <= len)
54f4b874 215 return NULL;
d79374c7
JH
216 if (path[0] == '~') {
217 if (!user_path(used_path, path, PATH_MAX))
218 return NULL;
219 strcpy(validated_path, path);
220 path = used_path;
221 }
222 else if (PATH_MAX - 10 < len)
223 return NULL;
224 else {
225 path = strcpy(used_path, path);
226 strcpy(validated_path, path);
227 }
228 len = strlen(path);
229 for (i = 0; suffix[i]; i++) {
230 strcpy(path + len, suffix[i]);
231 if (!access(path, F_OK)) {
232 strcat(validated_path, suffix[i]);
233 break;
234 }
235 }
236 if (!suffix[i] || chdir(path))
0870ca7f 237 return NULL;
d79374c7 238 path = validated_path;
0870ca7f 239 }
d79374c7
JH
240 else if (chdir(path))
241 return NULL;
54f4b874 242
d79374c7
JH
243 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
244 validate_symref("HEAD") == 0) {
54f4b874 245 putenv("GIT_DIR=.");
1644162a 246 check_repository_format();
d79374c7 247 return path;
54f4b874
AE
248 }
249
250 return NULL;
251}
138086a7
JH
252
253int adjust_shared_perm(const char *path)
254{
255 struct stat st;
256 int mode;
257
258 if (!shared_repository)
259 return 0;
260 if (lstat(path, &st) < 0)
261 return -1;
262 mode = st.st_mode;
263 if (mode & S_IRUSR)
94df2506
JH
264 mode |= (shared_repository == PERM_GROUP
265 ? S_IRGRP
266 : (shared_repository == PERM_EVERYBODY
267 ? (S_IRGRP|S_IROTH)
268 : 0));
269
138086a7
JH
270 if (mode & S_IWUSR)
271 mode |= S_IWGRP;
94df2506 272
138086a7 273 if (mode & S_IXUSR)
94df2506
JH
274 mode |= (shared_repository == PERM_GROUP
275 ? S_IXGRP
276 : (shared_repository == PERM_EVERYBODY
277 ? (S_IXGRP|S_IXOTH)
278 : 0));
138086a7
JH
279 if (S_ISDIR(mode))
280 mode |= S_ISGID;
fe732ede 281 if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
138086a7
JH
282 return -2;
283 return 0;
284}