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/* removes the last path component from 'path' except if 'path' is root */ 15static void strip_last_component(struct strbuf *path) 16{ 17 size_t offset = offset_1st_component(path->buf); 18 size_t len = path->len; 19 20 /* Find start of the last component */ 21 while (offset < len && !is_dir_sep(path->buf[len - 1])) 22 len--; 23 /* Skip sequences of multiple path-separators */ 24 while (offset < len && is_dir_sep(path->buf[len - 1])) 25 len--; 26 27 strbuf_setlen(path, len); 28} 29 30/* get (and remove) the next component in 'remaining' and place it in 'next' */ 31static void get_next_component(struct strbuf *next, struct strbuf *remaining) 32{ 33 char *start = NULL; 34 char *end = NULL; 35 36 strbuf_reset(next); 37 38 /* look for the next component */ 39 /* Skip sequences of multiple path-separators */ 40 for (start = remaining->buf; is_dir_sep(*start); start++) 41 ; /* nothing */ 42 /* Find end of the path component */ 43 for (end = start; *end && !is_dir_sep(*end); end++) 44 ; /* nothing */ 45 46 strbuf_add(next, start, end - start); 47 /* remove the component from 'remaining' */ 48 strbuf_remove(remaining, 0, end - remaining->buf); 49} 50 51/* copies root part from remaining to resolved, canonicalizing it on the way */ 52static void get_root_part(struct strbuf *resolved, struct strbuf *remaining) 53{ 54 int offset = offset_1st_component(remaining->buf); 55 56 strbuf_reset(resolved); 57 strbuf_add(resolved, remaining->buf, offset); 58#ifdef GIT_WINDOWS_NATIVE 59 convert_slashes(resolved->buf); 60#endif 61 strbuf_remove(remaining, 0, offset); 62} 63 64/* We allow "recursive" symbolic links. Only within reason, though. */ 65#define MAXSYMLINKS 5 66 67/* 68 * Return the real path (i.e., absolute path, with symlinks resolved 69 * and extra slashes removed) equivalent to the specified path. (If 70 * you want an absolute path but don't mind links, use 71 * absolute_path().) Places the resolved realpath in the provided strbuf. 72 * 73 * The directory part of path (i.e., everything up to the last 74 * dir_sep) must denote a valid, existing directory, but the last 75 * component need not exist. If die_on_error is set, then die with an 76 * informative error message if there is a problem. Otherwise, return 77 * NULL on errors (without generating any output). 78 */ 79char *strbuf_realpath(struct strbuf *resolved, const char *path, 80 int die_on_error) 81{ 82 struct strbuf remaining = STRBUF_INIT; 83 struct strbuf next = STRBUF_INIT; 84 struct strbuf symlink = STRBUF_INIT; 85 char *retval = NULL; 86 int num_symlinks = 0; 87 struct stat st; 88 89 if (!*path) { 90 if (die_on_error) 91 die("The empty string is not a valid path"); 92 else 93 goto error_out; 94 } 95 96 strbuf_addstr(&remaining, path); 97 get_root_part(resolved, &remaining); 98 99 if (!resolved->len) { 100 /* relative path; can use CWD as the initial resolved path */ 101 if (strbuf_getcwd(resolved)) { 102 if (die_on_error) 103 die_errno("unable to get current working directory"); 104 else 105 goto error_out; 106 } 107 } 108 109 /* Iterate over the remaining path components */ 110 while (remaining.len > 0) { 111 get_next_component(&next, &remaining); 112 113 if (next.len == 0) { 114 continue; /* empty component */ 115 } else if (next.len == 1 && !strcmp(next.buf, ".")) { 116 continue; /* '.' component */ 117 } else if (next.len == 2 && !strcmp(next.buf, "..")) { 118 /* '..' component; strip the last path component */ 119 strip_last_component(resolved); 120 continue; 121 } 122 123 /* append the next component and resolve resultant path */ 124 if (!is_dir_sep(resolved->buf[resolved->len - 1])) 125 strbuf_addch(resolved, '/'); 126 strbuf_addbuf(resolved, &next); 127 128 if (lstat(resolved->buf, &st)) { 129 /* error out unless this was the last component */ 130 if (errno != ENOENT || remaining.len) { 131 if (die_on_error) 132 die_errno("Invalid path '%s'", 133 resolved->buf); 134 else 135 goto error_out; 136 } 137 } else if (S_ISLNK(st.st_mode)) { 138 ssize_t len; 139 strbuf_reset(&symlink); 140 141 if (num_symlinks++ > MAXSYMLINKS) { 142 if (die_on_error) 143 die("More than %d nested symlinks " 144 "on path '%s'", MAXSYMLINKS, path); 145 else 146 goto error_out; 147 } 148 149 len = strbuf_readlink(&symlink, resolved->buf, 150 st.st_size); 151 if (len < 0) { 152 if (die_on_error) 153 die_errno("Invalid symlink '%s'", 154 resolved->buf); 155 else 156 goto error_out; 157 } 158 159 if (is_absolute_path(symlink.buf)) { 160 /* absolute symlink; set resolved to root */ 161 get_root_part(resolved, &symlink); 162 } else { 163 /* 164 * relative symlink 165 * strip off the last component since it will 166 * be replaced with the contents of the symlink 167 */ 168 strip_last_component(resolved); 169 } 170 171 /* 172 * if there are still remaining components to resolve 173 * then append them to symlink 174 */ 175 if (remaining.len) { 176 strbuf_addch(&symlink, '/'); 177 strbuf_addbuf(&symlink, &remaining); 178 } 179 180 /* 181 * use the symlink as the remaining components that 182 * need to be resloved 183 */ 184 strbuf_swap(&symlink, &remaining); 185 } 186 } 187 188 retval = resolved->buf; 189 190error_out: 191 strbuf_release(&remaining); 192 strbuf_release(&next); 193 strbuf_release(&symlink); 194 195 if (!retval) 196 strbuf_reset(resolved); 197 198 return retval; 199} 200 201const char *real_path(const char *path) 202{ 203 static struct strbuf realpath = STRBUF_INIT; 204 return strbuf_realpath(&realpath, path, 1); 205} 206 207const char *real_path_if_valid(const char *path) 208{ 209 static struct strbuf realpath = STRBUF_INIT; 210 return strbuf_realpath(&realpath, path, 0); 211} 212 213char *real_pathdup(const char *path) 214{ 215 struct strbuf realpath = STRBUF_INIT; 216 char *retval = NULL; 217 218 if (strbuf_realpath(&realpath, path, 0)) 219 retval = strbuf_detach(&realpath, NULL); 220 221 strbuf_release(&realpath); 222 223 return retval; 224} 225 226/* 227 * Use this to get an absolute path from a relative one. If you want 228 * to resolve links, you should use real_path. 229 */ 230const char *absolute_path(const char *path) 231{ 232 static struct strbuf sb = STRBUF_INIT; 233 strbuf_reset(&sb); 234 strbuf_add_absolute_path(&sb, path); 235 return sb.buf; 236} 237 238/* 239 * Unlike prefix_path, this should be used if the named file does 240 * not have to interact with index entry; i.e. name of a random file 241 * on the filesystem. 242 */ 243const char *prefix_filename(const char *pfx, int pfx_len, const char *arg) 244{ 245 static struct strbuf path = STRBUF_INIT; 246#ifndef GIT_WINDOWS_NATIVE 247 if (!pfx_len || is_absolute_path(arg)) 248 return arg; 249 strbuf_reset(&path); 250 strbuf_add(&path, pfx, pfx_len); 251 strbuf_addstr(&path, arg); 252#else 253 /* don't add prefix to absolute paths, but still replace '\' by '/' */ 254 strbuf_reset(&path); 255 if (is_absolute_path(arg)) 256 pfx_len = 0; 257 else if (pfx_len) 258 strbuf_add(&path, pfx, pfx_len); 259 strbuf_addstr(&path, arg); 260 convert_slashes(path.buf + pfx_len); 261#endif 262 return path.buf; 263}