Merge branch 'maint'
[git] / abspath.c
1 #include "cache.h"
2
3 /* We allow "recursive" symbolic links. Only within reason, though. */
4 #define MAXDEPTH 5
5
6 const char *make_absolute_path(const char *path)
7 {
8         static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
9         char cwd[1024] = "";
10         int buf_index = 1, len;
11
12         int depth = MAXDEPTH;
13         char *last_elem = NULL;
14         struct stat st;
15
16         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
17                 die ("Too long path: %.*s", 60, path);
18
19         while (depth--) {
20                 if (stat(buf, &st) || !S_ISDIR(st.st_mode)) {
21                         char *last_slash = strrchr(buf, '/');
22                         if (last_slash) {
23                                 *last_slash = '\0';
24                                 last_elem = xstrdup(last_slash + 1);
25                         } else {
26                                 last_elem = xstrdup(buf);
27                                 *buf = '\0';
28                         }
29                 }
30
31                 if (*buf) {
32                         if (!*cwd && !getcwd(cwd, sizeof(cwd)))
33                                 die ("Could not get current working directory");
34
35                         if (chdir(buf))
36                                 die ("Could not switch to '%s'", buf);
37                 }
38                 if (!getcwd(buf, PATH_MAX))
39                         die ("Could not get current working directory");
40
41                 if (last_elem) {
42                         int len = strlen(buf);
43                         if (len + strlen(last_elem) + 2 > PATH_MAX)
44                                 die ("Too long path name: '%s/%s'",
45                                                 buf, last_elem);
46                         buf[len] = '/';
47                         strcpy(buf + len + 1, last_elem);
48                         free(last_elem);
49                         last_elem = NULL;
50                 }
51
52                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
53                         len = readlink(buf, next_buf, PATH_MAX);
54                         if (len < 0)
55                                 die ("Invalid symlink: %s", buf);
56                         next_buf[len] = '\0';
57                         buf = next_buf;
58                         buf_index = 1 - buf_index;
59                         next_buf = bufs[buf_index];
60                 } else
61                         break;
62         }
63
64         if (*cwd && chdir(cwd))
65                 die ("Could not change back to '%s'", cwd);
66
67         return buf;
68 }
69
70 static const char *get_pwd_cwd(void)
71 {
72         static char cwd[PATH_MAX + 1];
73         char *pwd;
74         struct stat cwd_stat, pwd_stat;
75         if (getcwd(cwd, PATH_MAX) == NULL)
76                 return NULL;
77         pwd = getenv("PWD");
78         if (pwd && strcmp(pwd, cwd)) {
79                 stat(cwd, &cwd_stat);
80                 if (!stat(pwd, &pwd_stat) &&
81                     pwd_stat.st_dev == cwd_stat.st_dev &&
82                     pwd_stat.st_ino == cwd_stat.st_ino) {
83                         strlcpy(cwd, pwd, PATH_MAX);
84                 }
85         }
86         return cwd;
87 }
88
89 const char *make_nonrelative_path(const char *path)
90 {
91         static char buf[PATH_MAX + 1];
92
93         if (is_absolute_path(path)) {
94                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
95                         die("Too long path: %.*s", 60, path);
96         } else {
97                 const char *cwd = get_pwd_cwd();
98                 if (!cwd)
99                         die("Cannot determine the current working directory");
100                 if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
101                         die("Too long path: %.*s", 60, path);
102         }
103         return buf;
104 }