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 char cwd[1024] = ""; 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 && !getcwd(cwd, sizeof(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 && chdir(cwd)) 146 die_errno ("Could not change back to '%s'", cwd); 147 148 return retval; 149} 150 151const char *real_path(const char *path) 152{ 153 return real_path_internal(path, 1); 154} 155 156const char *real_path_if_valid(const char *path) 157{ 158 return real_path_internal(path, 0); 159} 160 161static const char *get_pwd_cwd(void) 162{ 163 static char cwd[PATH_MAX + 1]; 164 char *pwd; 165 struct stat cwd_stat, pwd_stat; 166 if (getcwd(cwd, PATH_MAX) == NULL) 167 return NULL; 168 pwd = getenv("PWD"); 169 if (pwd && strcmp(pwd, cwd)) { 170 stat(cwd, &cwd_stat); 171 if ((cwd_stat.st_dev || cwd_stat.st_ino) && 172 !stat(pwd, &pwd_stat) && 173 pwd_stat.st_dev == cwd_stat.st_dev && 174 pwd_stat.st_ino == cwd_stat.st_ino) { 175 strlcpy(cwd, pwd, PATH_MAX); 176 } 177 } 178 return cwd; 179} 180 181/* 182 * Use this to get an absolute path from a relative one. If you want 183 * to resolve links, you should use real_path. 184 * 185 * If the path is already absolute, then return path. As the user is 186 * never meant to free the return value, we're safe. 187 */ 188const char *absolute_path(const char *path) 189{ 190 static char buf[PATH_MAX + 1]; 191 192 if (!*path) { 193 die("The empty string is not a valid path"); 194 } else if (is_absolute_path(path)) { 195 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX) 196 die("Too long path: %.*s", 60, path); 197 } else { 198 size_t len; 199 const char *fmt; 200 const char *cwd = get_pwd_cwd(); 201 if (!cwd) 202 die_errno("Cannot determine the current working directory"); 203 len = strlen(cwd); 204 fmt = (len > 0 && is_dir_sep(cwd[len-1])) ? "%s%s" : "%s/%s"; 205 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX) 206 die("Too long path: %.*s", 60, path); 207 } 208 return buf; 209} 210 211/* 212 * Unlike prefix_path, this should be used if the named file does 213 * not have to interact with index entry; i.e. name of a random file 214 * on the filesystem. 215 */ 216const char *prefix_filename(const char *pfx, int pfx_len, const char *arg) 217{ 218 static char path[PATH_MAX]; 219#ifndef GIT_WINDOWS_NATIVE 220 if (!pfx_len || is_absolute_path(arg)) 221 return arg; 222 memcpy(path, pfx, pfx_len); 223 strcpy(path + pfx_len, arg); 224#else 225 char *p; 226 /* don't add prefix to absolute paths, but still replace '\' by '/' */ 227 if (is_absolute_path(arg)) 228 pfx_len = 0; 229 else if (pfx_len) 230 memcpy(path, pfx, pfx_len); 231 strcpy(path + pfx_len, arg); 232 for (p = path + pfx_len; *p; p++) 233 if (*p == '\\') 234 *p = '/'; 235#endif 236 return path; 237}