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/* We allow "recursive" symbolic links. Only within reason, though. */ 52#define MAXSYMLINKS 5 53 54/* 55 * Return the real path (i.e., absolute path, with symlinks resolved 56 * and extra slashes removed) equivalent to the specified path. (If 57 * you want an absolute path but don't mind links, use 58 * absolute_path().) Places the resolved realpath in the provided strbuf. 59 * 60 * The directory part of path (i.e., everything up to the last 61 * dir_sep) must denote a valid, existing directory, but the last 62 * component need not exist. If die_on_error is set, then die with an 63 * informative error message if there is a problem. Otherwise, return 64 * NULL on errors (without generating any output). 65 */ 66char *strbuf_realpath(struct strbuf *resolved, const char *path, 67 int die_on_error) 68{ 69 struct strbuf remaining = STRBUF_INIT; 70 struct strbuf next = STRBUF_INIT; 71 struct strbuf symlink = STRBUF_INIT; 72 char *retval = NULL; 73 int num_symlinks = 0; 74 struct stat st; 75 76 if (!*path) { 77 if (die_on_error) 78 die("The empty string is not a valid path"); 79 else 80 goto error_out; 81 } 82 83 strbuf_reset(resolved); 84 85 if (is_absolute_path(path)) { 86 /* absolute path; start with only root as being resolved */ 87 int offset = offset_1st_component(path); 88 strbuf_add(resolved, path, offset); 89 strbuf_addstr(&remaining, path + offset); 90 } else { 91 /* relative path; can use CWD as the initial resolved path */ 92 if (strbuf_getcwd(resolved)) { 93 if (die_on_error) 94 die_errno("unable to get current working directory"); 95 else 96 goto error_out; 97 } 98 strbuf_addstr(&remaining, path); 99 } 100 101 /* Iterate over the remaining path components */ 102 while (remaining.len > 0) { 103 get_next_component(&next, &remaining); 104 105 if (next.len == 0) { 106 continue; /* empty component */ 107 } else if (next.len == 1 && !strcmp(next.buf, ".")) { 108 continue; /* '.' component */ 109 } else if (next.len == 2 && !strcmp(next.buf, "..")) { 110 /* '..' component; strip the last path component */ 111 strip_last_component(resolved); 112 continue; 113 } 114 115 /* append the next component and resolve resultant path */ 116 if (!is_dir_sep(resolved->buf[resolved->len - 1])) 117 strbuf_addch(resolved, '/'); 118 strbuf_addbuf(resolved, &next); 119 120 if (lstat(resolved->buf, &st)) { 121 /* error out unless this was the last component */ 122 if (errno != ENOENT || remaining.len) { 123 if (die_on_error) 124 die_errno("Invalid path '%s'", 125 resolved->buf); 126 else 127 goto error_out; 128 } 129 } else if (S_ISLNK(st.st_mode)) { 130 ssize_t len; 131 strbuf_reset(&symlink); 132 133 if (num_symlinks++ > MAXSYMLINKS) { 134 if (die_on_error) 135 die("More than %d nested symlinks " 136 "on path '%s'", MAXSYMLINKS, path); 137 else 138 goto error_out; 139 } 140 141 len = strbuf_readlink(&symlink, resolved->buf, 142 st.st_size); 143 if (len < 0) { 144 if (die_on_error) 145 die_errno("Invalid symlink '%s'", 146 resolved->buf); 147 else 148 goto error_out; 149 } 150 151 if (is_absolute_path(symlink.buf)) { 152 /* absolute symlink; set resolved to root */ 153 int offset = offset_1st_component(symlink.buf); 154 strbuf_reset(resolved); 155 strbuf_add(resolved, symlink.buf, offset); 156 strbuf_remove(&symlink, 0, offset); 157 } else { 158 /* 159 * relative symlink 160 * strip off the last component since it will 161 * be replaced with the contents of the symlink 162 */ 163 strip_last_component(resolved); 164 } 165 166 /* 167 * if there are still remaining components to resolve 168 * then append them to symlink 169 */ 170 if (remaining.len) { 171 strbuf_addch(&symlink, '/'); 172 strbuf_addbuf(&symlink, &remaining); 173 } 174 175 /* 176 * use the symlink as the remaining components that 177 * need to be resloved 178 */ 179 strbuf_swap(&symlink, &remaining); 180 } 181 } 182 183 retval = resolved->buf; 184 185error_out: 186 strbuf_release(&remaining); 187 strbuf_release(&next); 188 strbuf_release(&symlink); 189 190 if (!retval) 191 strbuf_reset(resolved); 192 193 return retval; 194} 195 196const char *real_path(const char *path) 197{ 198 static struct strbuf realpath = STRBUF_INIT; 199 return strbuf_realpath(&realpath, path, 1); 200} 201 202const char *real_path_if_valid(const char *path) 203{ 204 static struct strbuf realpath = STRBUF_INIT; 205 return strbuf_realpath(&realpath, path, 0); 206} 207 208/* 209 * Use this to get an absolute path from a relative one. If you want 210 * to resolve links, you should use real_path. 211 */ 212const char *absolute_path(const char *path) 213{ 214 static struct strbuf sb = STRBUF_INIT; 215 strbuf_reset(&sb); 216 strbuf_add_absolute_path(&sb, path); 217 return sb.buf; 218} 219 220/* 221 * Unlike prefix_path, this should be used if the named file does 222 * not have to interact with index entry; i.e. name of a random file 223 * on the filesystem. 224 */ 225const char *prefix_filename(const char *pfx, int pfx_len, const char *arg) 226{ 227 static struct strbuf path = STRBUF_INIT; 228#ifndef GIT_WINDOWS_NATIVE 229 if (!pfx_len || is_absolute_path(arg)) 230 return arg; 231 strbuf_reset(&path); 232 strbuf_add(&path, pfx, pfx_len); 233 strbuf_addstr(&path, arg); 234#else 235 /* don't add prefix to absolute paths, but still replace '\' by '/' */ 236 strbuf_reset(&path); 237 if (is_absolute_path(arg)) 238 pfx_len = 0; 239 else if (pfx_len) 240 strbuf_add(&path, pfx, pfx_len); 241 strbuf_addstr(&path, arg); 242 convert_slashes(path.buf + pfx_len); 243#endif 244 return path.buf; 245}