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 * 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). 30 * 31 * If path is our buffer, then return path, as it's already what the 32 * user wants. 33 */ 34static const char *real_path_internal(const char *path, int die_on_error) 35{ 36 static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1]; 37 char *retval = NULL; 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 */ 44 struct strbuf cwd = STRBUF_INIT; 45 46 int buf_index = 1; 47 48 int depth = MAXDEPTH; 49 char *last_elem = NULL; 50 struct stat st; 51 52 /* We've already done it */ 53 if (path == buf || path == next_buf) 54 return path; 55 56 if (!*path) { 57 if (die_on_error) 58 die("The empty string is not a valid path"); 59 else 60 goto error_out; 61 } 62 63 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX) { 64 if (die_on_error) 65 die("Too long path: %.*s", 60, path); 66 else 67 goto error_out; 68 } 69 70 while (depth--) { 71 if (!is_directory(buf)) { 72 char *last_slash = find_last_dir_sep(buf); 73 if (last_slash) { 74 last_elem = xstrdup(last_slash + 1); 75 last_slash[1] = '\0'; 76 } else { 77 last_elem = xstrdup(buf); 78 *buf = '\0'; 79 } 80 } 81 82 if (*buf) { 83 if (!cwd.len && strbuf_getcwd(&cwd)) { 84 if (die_on_error) 85 die_errno("Could not get current working directory"); 86 else 87 goto error_out; 88 } 89 90 if (chdir(buf)) { 91 if (die_on_error) 92 die_errno("Could not switch to '%s'", buf); 93 else 94 goto error_out; 95 } 96 } 97 if (!getcwd(buf, PATH_MAX)) { 98 if (die_on_error) 99 die_errno("Could not get current working directory"); 100 else 101 goto error_out; 102 } 103 104 if (last_elem) { 105 size_t len = strlen(buf); 106 if (len + strlen(last_elem) + 2 > PATH_MAX) { 107 if (die_on_error) 108 die("Too long path name: '%s/%s'", 109 buf, last_elem); 110 else 111 goto error_out; 112 } 113 if (len && !is_dir_sep(buf[len - 1])) 114 buf[len++] = '/'; 115 strcpy(buf + len, last_elem); 116 free(last_elem); 117 last_elem = NULL; 118 } 119 120 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) { 121 ssize_t len = readlink(buf, next_buf, PATH_MAX); 122 if (len < 0) { 123 if (die_on_error) 124 die_errno("Invalid symlink '%s'", buf); 125 else 126 goto error_out; 127 } 128 if (PATH_MAX <= len) { 129 if (die_on_error) 130 die("symbolic link too long: %s", buf); 131 else 132 goto error_out; 133 } 134 next_buf[len] = '\0'; 135 buf = next_buf; 136 buf_index = 1 - buf_index; 137 next_buf = bufs[buf_index]; 138 } else 139 break; 140 } 141 142 retval = buf; 143error_out: 144 free(last_elem); 145 if (cwd.len && chdir(cwd.buf)) 146 die_errno("Could not change back to '%s'", cwd.buf); 147 strbuf_release(&cwd); 148 149 return retval; 150} 151 152const char *real_path(const char *path) 153{ 154 return real_path_internal(path, 1); 155} 156 157const char *real_path_if_valid(const char *path) 158{ 159 return real_path_internal(path, 0); 160} 161 162static const char *get_pwd_cwd(void) 163{ 164 static char cwd[PATH_MAX + 1]; 165 char *pwd; 166 struct stat cwd_stat, pwd_stat; 167 if (getcwd(cwd, PATH_MAX) == NULL) 168 return NULL; 169 pwd = getenv("PWD"); 170 if (pwd && strcmp(pwd, cwd)) { 171 stat(cwd, &cwd_stat); 172 if ((cwd_stat.st_dev || cwd_stat.st_ino) && 173 !stat(pwd, &pwd_stat) && 174 pwd_stat.st_dev == cwd_stat.st_dev && 175 pwd_stat.st_ino == cwd_stat.st_ino) { 176 strlcpy(cwd, pwd, PATH_MAX); 177 } 178 } 179 return cwd; 180} 181 182/* 183 * Use this to get an absolute path from a relative one. If you want 184 * to resolve links, you should use real_path. 185 * 186 * If the path is already absolute, then return path. As the user is 187 * never meant to free the return value, we're safe. 188 */ 189const char *absolute_path(const char *path) 190{ 191 static char buf[PATH_MAX + 1]; 192 193 if (!*path) { 194 die("The empty string is not a valid path"); 195 } else if (is_absolute_path(path)) { 196 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX) 197 die("Too long path: %.*s", 60, path); 198 } else { 199 size_t len; 200 const char *fmt; 201 const char *cwd = get_pwd_cwd(); 202 if (!cwd) 203 die_errno("Cannot determine the current working directory"); 204 len = strlen(cwd); 205 fmt = (len > 0 && is_dir_sep(cwd[len - 1])) ? "%s%s" : "%s/%s"; 206 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX) 207 die("Too long path: %.*s", 60, path); 208 } 209 return buf; 210} 211 212/* 213 * Unlike prefix_path, this should be used if the named file does 214 * not have to interact with index entry; i.e. name of a random file 215 * on the filesystem. 216 */ 217const char *prefix_filename(const char *pfx, int pfx_len, const char *arg) 218{ 219 static struct strbuf path = STRBUF_INIT; 220#ifndef GIT_WINDOWS_NATIVE 221 if (!pfx_len || is_absolute_path(arg)) 222 return arg; 223 strbuf_reset(&path); 224 strbuf_add(&path, pfx, pfx_len); 225 strbuf_addstr(&path, arg); 226#else 227 char *p; 228 /* don't add prefix to absolute paths, but still replace '\' by '/' */ 229 strbuf_reset(&path); 230 if (is_absolute_path(arg)) 231 pfx_len = 0; 232 else if (pfx_len) 233 strbuf_add(&path, pfx, pfx_len); 234 strbuf_addstr(&path, arg); 235 for (p = path.buf + pfx_len; *p; p++) 236 if (*p == '\\') 237 *p = '/'; 238#endif 239 return path.buf; 240}