parse-options: export opterr, optbug
[git/git.git] / abspath.c
... / ...
CommitLineData
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 */
8int 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/*
18 * Use this to get the real path, i.e. resolve links. If you want an
19 * absolute path but don't mind links, use absolute_path.
20 *
21 * If path is our buffer, then return path, as it's already what the
22 * user wants.
23 */
24const char *real_path(const char *path)
25{
26 static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
27 char cwd[1024] = "";
28 int buf_index = 1;
29
30 int depth = MAXDEPTH;
31 char *last_elem = NULL;
32 struct stat st;
33
34 /* We've already done it */
35 if (path == buf || path == next_buf)
36 return path;
37
38 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
39 die ("Too long path: %.*s", 60, path);
40
41 while (depth--) {
42 if (!is_directory(buf)) {
43 char *last_slash = find_last_dir_sep(buf);
44 if (last_slash) {
45 *last_slash = '\0';
46 last_elem = xstrdup(last_slash + 1);
47 } else {
48 last_elem = xstrdup(buf);
49 *buf = '\0';
50 }
51 }
52
53 if (*buf) {
54 if (!*cwd && !getcwd(cwd, sizeof(cwd)))
55 die_errno ("Could not get current working directory");
56
57 if (chdir(buf))
58 die_errno ("Could not switch to '%s'", buf);
59 }
60 if (!getcwd(buf, PATH_MAX))
61 die_errno ("Could not get current working directory");
62
63 if (last_elem) {
64 size_t len = strlen(buf);
65 if (len + strlen(last_elem) + 2 > PATH_MAX)
66 die ("Too long path name: '%s/%s'",
67 buf, last_elem);
68 if (len && !is_dir_sep(buf[len-1]))
69 buf[len++] = '/';
70 strcpy(buf + len, last_elem);
71 free(last_elem);
72 last_elem = NULL;
73 }
74
75 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
76 ssize_t len = readlink(buf, next_buf, PATH_MAX);
77 if (len < 0)
78 die_errno ("Invalid symlink '%s'", buf);
79 if (PATH_MAX <= len)
80 die("symbolic link too long: %s", buf);
81 next_buf[len] = '\0';
82 buf = next_buf;
83 buf_index = 1 - buf_index;
84 next_buf = bufs[buf_index];
85 } else
86 break;
87 }
88
89 if (*cwd && chdir(cwd))
90 die_errno ("Could not change back to '%s'", cwd);
91
92 return buf;
93}
94
95static const char *get_pwd_cwd(void)
96{
97 static char cwd[PATH_MAX + 1];
98 char *pwd;
99 struct stat cwd_stat, pwd_stat;
100 if (getcwd(cwd, PATH_MAX) == NULL)
101 return NULL;
102 pwd = getenv("PWD");
103 if (pwd && strcmp(pwd, cwd)) {
104 stat(cwd, &cwd_stat);
105 if ((cwd_stat.st_dev || cwd_stat.st_ino) &&
106 !stat(pwd, &pwd_stat) &&
107 pwd_stat.st_dev == cwd_stat.st_dev &&
108 pwd_stat.st_ino == cwd_stat.st_ino) {
109 strlcpy(cwd, pwd, PATH_MAX);
110 }
111 }
112 return cwd;
113}
114
115/*
116 * Use this to get an absolute path from a relative one. If you want
117 * to resolve links, you should use real_path.
118 *
119 * If the path is already absolute, then return path. As the user is
120 * never meant to free the return value, we're safe.
121 */
122const char *absolute_path(const char *path)
123{
124 static char buf[PATH_MAX + 1];
125
126 if (is_absolute_path(path)) {
127 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
128 die("Too long path: %.*s", 60, path);
129 } else {
130 size_t len;
131 const char *fmt;
132 const char *cwd = get_pwd_cwd();
133 if (!cwd)
134 die_errno("Cannot determine the current working directory");
135 len = strlen(cwd);
136 fmt = (len > 0 && is_dir_sep(cwd[len-1])) ? "%s%s" : "%s/%s";
137 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX)
138 die("Too long path: %.*s", 60, path);
139 }
140 return buf;
141}