use xgetcwd() to set $GIT_DIR
[git/git.git] / abspath.c
CommitLineData
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DP
1#include "cache.h"
2
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JH
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
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14/* We allow "recursive" symbolic links. Only within reason, though. */
15#define MAXDEPTH 5
16
e2a57aac 17/*
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MH
18 * Return the real path (i.e., absolute path, with symlinks resolved
19 * and extra slashes removed) equivalent to the specified path. (If
20 * you want an absolute path but don't mind links, use
21 * absolute_path().) The return value is a pointer to a static
22 * buffer.
23 *
24 * The input and all intermediate paths must be shorter than MAX_PATH.
25 * The directory part of path (i.e., everything up to the last
26 * dir_sep) must denote a valid, existing directory, but the last
27 * component need not exist. If die_on_error is set, then die with an
28 * informative error message if there is a problem. Otherwise, return
29 * NULL on errors (without generating any output).
e2a57aac
CMN
30 *
31 * If path is our buffer, then return path, as it's already what the
32 * user wants.
33 */
038e55fe 34static const char *real_path_internal(const char *path, int die_on_error)
5b8e6f85 35{
2fdb9ce0 36 static struct strbuf sb = STRBUF_INIT;
038e55fe 37 char *retval = NULL;
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MH
38
39 /*
40 * If we have to temporarily chdir(), store the original CWD
41 * here so that we can chdir() back to it at the end of the
42 * function:
43 */
251277ac 44 struct strbuf cwd = STRBUF_INIT;
d6052abc 45
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46 int depth = MAXDEPTH;
47 char *last_elem = NULL;
48 struct stat st;
49
1d679de5 50 /* We've already done it */
2fdb9ce0 51 if (path == sb.buf)
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CMN
52 return path;
53
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54 if (!*path) {
55 if (die_on_error)
56 die("The empty string is not a valid path");
57 else
58 goto error_out;
59 }
3efe5d1d 60
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RS
61 strbuf_reset(&sb);
62 strbuf_addstr(&sb, path);
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63
64 while (depth--) {
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65 if (!is_directory(sb.buf)) {
66 char *last_slash = find_last_dir_sep(sb.buf);
5b8e6f85 67 if (last_slash) {
5b8e6f85 68 last_elem = xstrdup(last_slash + 1);
2fdb9ce0 69 strbuf_setlen(&sb, last_slash - sb.buf + 1);
5b8e6f85 70 } else {
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RS
71 last_elem = xmemdupz(sb.buf, sb.len);
72 strbuf_reset(&sb);
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73 }
74 }
75
2fdb9ce0 76 if (sb.len) {
251277ac 77 if (!cwd.len && strbuf_getcwd(&cwd)) {
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78 if (die_on_error)
79 die_errno("Could not get current working directory");
80 else
81 goto error_out;
82 }
5b8e6f85 83
2fdb9ce0 84 if (chdir(sb.buf)) {
038e55fe 85 if (die_on_error)
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RS
86 die_errno("Could not switch to '%s'",
87 sb.buf);
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88 else
89 goto error_out;
90 }
91 }
2fdb9ce0 92 if (strbuf_getcwd(&sb)) {
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93 if (die_on_error)
94 die_errno("Could not get current working directory");
95 else
96 goto error_out;
5b8e6f85 97 }
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98
99 if (last_elem) {
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100 if (sb.len && !is_dir_sep(sb.buf[sb.len - 1]))
101 strbuf_addch(&sb, '/');
102 strbuf_addstr(&sb, last_elem);
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103 free(last_elem);
104 last_elem = NULL;
105 }
106
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107 if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) {
108 struct strbuf next_sb = STRBUF_INIT;
109 ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0);
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110 if (len < 0) {
111 if (die_on_error)
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112 die_errno("Invalid symlink '%s'",
113 sb.buf);
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114 else
115 goto error_out;
116 }
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117 strbuf_swap(&sb, &next_sb);
118 strbuf_release(&next_sb);
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119 } else
120 break;
121 }
122
2fdb9ce0 123 retval = sb.buf;
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124error_out:
125 free(last_elem);
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126 if (cwd.len && chdir(cwd.buf))
127 die_errno("Could not change back to '%s'", cwd.buf);
128 strbuf_release(&cwd);
5b8e6f85 129
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130 return retval;
131}
132
133const char *real_path(const char *path)
134{
135 return real_path_internal(path, 1);
5b8e6f85 136}
10c4c881 137
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MH
138const char *real_path_if_valid(const char *path)
139{
140 return real_path_internal(path, 0);
141}
142
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143static const char *get_pwd_cwd(void)
144{
145 static char cwd[PATH_MAX + 1];
146 char *pwd;
147 struct stat cwd_stat, pwd_stat;
148 if (getcwd(cwd, PATH_MAX) == NULL)
149 return NULL;
150 pwd = getenv("PWD");
151 if (pwd && strcmp(pwd, cwd)) {
152 stat(cwd, &cwd_stat);
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153 if ((cwd_stat.st_dev || cwd_stat.st_ino) &&
154 !stat(pwd, &pwd_stat) &&
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155 pwd_stat.st_dev == cwd_stat.st_dev &&
156 pwd_stat.st_ino == cwd_stat.st_ino) {
157 strlcpy(cwd, pwd, PATH_MAX);
158 }
159 }
160 return cwd;
161}
162
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CMN
163/*
164 * Use this to get an absolute path from a relative one. If you want
165 * to resolve links, you should use real_path.
166 *
167 * If the path is already absolute, then return path. As the user is
168 * never meant to free the return value, we're safe.
169 */
170const char *absolute_path(const char *path)
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171{
172 static char buf[PATH_MAX + 1];
173
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MH
174 if (!*path) {
175 die("The empty string is not a valid path");
176 } else if (is_absolute_path(path)) {
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177 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
178 die("Too long path: %.*s", 60, path);
179 } else {
b248e950
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180 size_t len;
181 const char *fmt;
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182 const char *cwd = get_pwd_cwd();
183 if (!cwd)
0721c314 184 die_errno("Cannot determine the current working directory");
b248e950 185 len = strlen(cwd);
f1e835fa 186 fmt = (len > 0 && is_dir_sep(cwd[len - 1])) ? "%s%s" : "%s/%s";
b248e950 187 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX)
10c4c881
JS
188 die("Too long path: %.*s", 60, path);
189 }
190 return buf;
191}
06876284
DI
192
193/*
194 * Unlike prefix_path, this should be used if the named file does
195 * not have to interact with index entry; i.e. name of a random file
196 * on the filesystem.
197 */
198const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
199{
fc2b6214 200 static struct strbuf path = STRBUF_INIT;
380395d0 201#ifndef GIT_WINDOWS_NATIVE
06876284
DI
202 if (!pfx_len || is_absolute_path(arg))
203 return arg;
fc2b6214
AP
204 strbuf_reset(&path);
205 strbuf_add(&path, pfx, pfx_len);
206 strbuf_addstr(&path, arg);
06876284
DI
207#else
208 char *p;
209 /* don't add prefix to absolute paths, but still replace '\' by '/' */
fc2b6214 210 strbuf_reset(&path);
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211 if (is_absolute_path(arg))
212 pfx_len = 0;
213 else if (pfx_len)
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214 strbuf_add(&path, pfx, pfx_len);
215 strbuf_addstr(&path, arg);
216 for (p = path.buf + pfx_len; *p; p++)
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217 if (*p == '\\')
218 *p = '/';
219#endif
fc2b6214 220 return path.buf;
06876284 221}