Thread-safe xmalloc and xrealloc needs a recursive mutex
[git/dscho.git] / abspath.c
blobb88122cbe73ec0c438e2d375fdebd51e5febf9ae
1 #include "cache.h"
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)
10         struct stat st;
11         return (!stat(path, &st) && S_ISDIR(st.st_mode));
14 /* We allow "recursive" symbolic links. Only within reason, though. */
15 #define MAXDEPTH 5
17 const char *make_absolute_path(const char *path)
19         static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
20         char cwd[1024] = "";
21         int buf_index = 1;
23         int depth = MAXDEPTH;
24         char *last_elem = NULL;
25         struct stat st;
27         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
28                 die ("Too long path: %.*s", 60, path);
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                 }
42                 if (*buf) {
43                         if (!*cwd && !getcwd(cwd, sizeof(cwd)))
44                                 die_errno ("Could not get current working directory");
46                         if (chdir(buf))
47                                 die_errno ("Could not switch to '%s'", buf);
48                 }
49                 if (!getcwd(buf, PATH_MAX))
50                         die_errno ("Could not get current working directory");
52                 if (last_elem) {
53                         size_t 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                 }
63                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
64                         ssize_t len = readlink(buf, next_buf, PATH_MAX);
65                         if (len < 0)
66                                 die_errno ("Invalid symlink '%s'", buf);
67                         if (PATH_MAX <= len)
68                                 die("symbolic link too long: %s", buf);
69                         next_buf[len] = '\0';
70                         buf = next_buf;
71                         buf_index = 1 - buf_index;
72                         next_buf = bufs[buf_index];
73                 } else
74                         break;
75         }
77         if (*cwd && chdir(cwd))
78                 die_errno ("Could not change back to '%s'", cwd);
80         return buf;
83 static const char *get_pwd_cwd(void)
85         static char cwd[PATH_MAX + 1];
86         char *pwd;
87         struct stat cwd_stat, pwd_stat;
88         if (getcwd(cwd, PATH_MAX) == NULL)
89                 return NULL;
90         pwd = getenv("PWD");
91         if (pwd && strcmp(pwd, cwd)) {
92                 stat(cwd, &cwd_stat);
93                 if (!stat(pwd, &pwd_stat) &&
94                     pwd_stat.st_dev == cwd_stat.st_dev &&
95                     pwd_stat.st_ino == cwd_stat.st_ino) {
96                         strlcpy(cwd, pwd, PATH_MAX);
97                 }
98         }
99         return cwd;
102 const char *make_nonrelative_path(const char *path)
104         static char buf[PATH_MAX + 1];
106         if (is_absolute_path(path)) {
107                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
108                         die("Too long path: %.*s", 60, path);
109         } else {
110                 const char *cwd = get_pwd_cwd();
111                 if (!cwd)
112                         die_errno("Cannot determine the current working directory");
113                 if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
114                         die("Too long path: %.*s", 60, path);
115         }
116         return buf;