print an error message for invalid path
[git] / abspath.c
1 #include "cache.h"
2
3 /*
4  * Do not use this for inspecting *tracked* content.  When path is a
5  * symlink to a directory, we do not want to say it is a directory when
6  * dealing with tracked content in the working tree.
7  */
8 int is_directory(const char *path)
9 {
10         struct stat st;
11         return (!stat(path, &st) && S_ISDIR(st.st_mode));
12 }
13
14 /* We allow "recursive" symbolic links. Only within reason, though. */
15 #define MAXDEPTH 5
16
17 const char *make_absolute_path(const char *path)
18 {
19         static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
20         char cwd[1024] = "";
21         int buf_index = 1, len;
22
23         int depth = MAXDEPTH;
24         char *last_elem = NULL;
25         struct stat st;
26
27         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
28                 die ("Too long path: %.*s", 60, path);
29
30         while (depth--) {
31                 if (!is_directory(buf)) {
32                         char *last_slash = strrchr(buf, '/');
33                         if (last_slash) {
34                                 *last_slash = '\0';
35                                 last_elem = xstrdup(last_slash + 1);
36                         } else {
37                                 last_elem = xstrdup(buf);
38                                 *buf = '\0';
39                         }
40                 }
41
42                 if (*buf) {
43                         if (!*cwd && !getcwd(cwd, sizeof(cwd)))
44                                 die ("Could not get current working directory");
45
46                         if (chdir(buf))
47                                 die ("Could not switch to '%s'", buf);
48                 }
49                 if (!getcwd(buf, PATH_MAX))
50                         die ("Could not get current working directory");
51
52                 if (last_elem) {
53                         int len = strlen(buf);
54                         if (len + strlen(last_elem) + 2 > PATH_MAX)
55                                 die ("Too long path name: '%s/%s'",
56                                                 buf, last_elem);
57                         buf[len] = '/';
58                         strcpy(buf + len + 1, last_elem);
59                         free(last_elem);
60                         last_elem = NULL;
61                 }
62
63                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
64                         len = readlink(buf, next_buf, PATH_MAX);
65                         if (len < 0)
66                                 die ("Invalid symlink: %s", buf);
67                         next_buf[len] = '\0';
68                         buf = next_buf;
69                         buf_index = 1 - buf_index;
70                         next_buf = bufs[buf_index];
71                 } else
72                         break;
73         }
74
75         if (*cwd && chdir(cwd))
76                 die ("Could not change back to '%s'", cwd);
77
78         return buf;
79 }
80
81 static const char *get_pwd_cwd(void)
82 {
83         static char cwd[PATH_MAX + 1];
84         char *pwd;
85         struct stat cwd_stat, pwd_stat;
86         if (getcwd(cwd, PATH_MAX) == NULL)
87                 return NULL;
88         pwd = getenv("PWD");
89         if (pwd && strcmp(pwd, cwd)) {
90                 stat(cwd, &cwd_stat);
91                 if (!stat(pwd, &pwd_stat) &&
92                     pwd_stat.st_dev == cwd_stat.st_dev &&
93                     pwd_stat.st_ino == cwd_stat.st_ino) {
94                         strlcpy(cwd, pwd, PATH_MAX);
95                 }
96         }
97         return cwd;
98 }
99
100 const char *make_nonrelative_path(const char *path)
101 {
102         static char buf[PATH_MAX + 1];
103
104         if (is_absolute_path(path)) {
105                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
106                         die("Too long path: %.*s", 60, path);
107         } else {
108                 const char *cwd = get_pwd_cwd();
109                 if (!cwd)
110                         die("Cannot determine the current working directory");
111                 if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
112                         die("Too long path: %.*s", 60, path);
113         }
114         return buf;
115 }