diff options
Diffstat (limited to 'abspath.c')
| -rw-r--r-- | abspath.c | 238 |
1 files changed, 166 insertions, 72 deletions
@@ -11,46 +11,83 @@ int is_directory(const char *path) return (!stat(path, &st) && S_ISDIR(st.st_mode)); } +/* removes the last path component from 'path' except if 'path' is root */ +static void strip_last_component(struct strbuf *path) +{ + size_t offset = offset_1st_component(path->buf); + size_t len = path->len; + + /* Find start of the last component */ + while (offset < len && !is_dir_sep(path->buf[len - 1])) + len--; + /* Skip sequences of multiple path-separators */ + while (offset < len && is_dir_sep(path->buf[len - 1])) + len--; + + strbuf_setlen(path, len); +} + +/* get (and remove) the next component in 'remaining' and place it in 'next' */ +static void get_next_component(struct strbuf *next, struct strbuf *remaining) +{ + char *start = NULL; + char *end = NULL; + + strbuf_reset(next); + + /* look for the next component */ + /* Skip sequences of multiple path-separators */ + for (start = remaining->buf; is_dir_sep(*start); start++) + ; /* nothing */ + /* Find end of the path component */ + for (end = start; *end && !is_dir_sep(*end); end++) + ; /* nothing */ + + strbuf_add(next, start, end - start); + /* remove the component from 'remaining' */ + strbuf_remove(remaining, 0, end - remaining->buf); +} + +/* copies root part from remaining to resolved, canonicalizing it on the way */ +static void get_root_part(struct strbuf *resolved, struct strbuf *remaining) +{ + int offset = offset_1st_component(remaining->buf); + + strbuf_reset(resolved); + strbuf_add(resolved, remaining->buf, offset); +#ifdef GIT_WINDOWS_NATIVE + convert_slashes(resolved->buf); +#endif + strbuf_remove(remaining, 0, offset); +} + /* We allow "recursive" symbolic links. Only within reason, though. */ -#define MAXDEPTH 5 +#ifndef MAXSYMLINKS +#define MAXSYMLINKS 32 +#endif /* * Return the real path (i.e., absolute path, with symlinks resolved * and extra slashes removed) equivalent to the specified path. (If * you want an absolute path but don't mind links, use - * absolute_path().) The return value is a pointer to a static - * buffer. + * absolute_path().) Places the resolved realpath in the provided strbuf. * - * The input and all intermediate paths must be shorter than MAX_PATH. * The directory part of path (i.e., everything up to the last * dir_sep) must denote a valid, existing directory, but the last * component need not exist. If die_on_error is set, then die with an * informative error message if there is a problem. Otherwise, return * NULL on errors (without generating any output). - * - * If path is our buffer, then return path, as it's already what the - * user wants. */ -static const char *real_path_internal(const char *path, int die_on_error) +char *strbuf_realpath(struct strbuf *resolved, const char *path, + int die_on_error) { - static struct strbuf sb = STRBUF_INIT; + struct strbuf remaining = STRBUF_INIT; + struct strbuf next = STRBUF_INIT; + struct strbuf symlink = STRBUF_INIT; char *retval = NULL; - - /* - * If we have to temporarily chdir(), store the original CWD - * here so that we can chdir() back to it at the end of the - * function: - */ - struct strbuf cwd = STRBUF_INIT; - - int depth = MAXDEPTH; - char *last_elem = NULL; + int num_symlinks = 0; struct stat st; - /* We've already done it */ - if (path == sb.buf) - return path; - if (!*path) { if (die_on_error) die("The empty string is not a valid path"); @@ -58,86 +95,136 @@ static const char *real_path_internal(const char *path, int die_on_error) goto error_out; } - strbuf_reset(&sb); - strbuf_addstr(&sb, path); - - while (depth--) { - if (!is_directory(sb.buf)) { - char *last_slash = find_last_dir_sep(sb.buf); - if (last_slash) { - last_elem = xstrdup(last_slash + 1); - strbuf_setlen(&sb, last_slash - sb.buf + 1); - } else { - last_elem = xmemdupz(sb.buf, sb.len); - strbuf_reset(&sb); - } + strbuf_addstr(&remaining, path); + get_root_part(resolved, &remaining); + + if (!resolved->len) { + /* relative path; can use CWD as the initial resolved path */ + if (strbuf_getcwd(resolved)) { + if (die_on_error) + die_errno("unable to get current working directory"); + else + goto error_out; } + } - if (sb.len) { - if (!cwd.len && strbuf_getcwd(&cwd)) { + /* Iterate over the remaining path components */ + while (remaining.len > 0) { + get_next_component(&next, &remaining); + + if (next.len == 0) { + continue; /* empty component */ + } else if (next.len == 1 && !strcmp(next.buf, ".")) { + continue; /* '.' component */ + } else if (next.len == 2 && !strcmp(next.buf, "..")) { + /* '..' component; strip the last path component */ + strip_last_component(resolved); + continue; + } + + /* append the next component and resolve resultant path */ + if (!is_dir_sep(resolved->buf[resolved->len - 1])) + strbuf_addch(resolved, '/'); + strbuf_addbuf(resolved, &next); + + if (lstat(resolved->buf, &st)) { + /* error out unless this was the last component */ + if (errno != ENOENT || remaining.len) { if (die_on_error) - die_errno("Could not get current working directory"); + die_errno("Invalid path '%s'", + resolved->buf); else goto error_out; } + } else if (S_ISLNK(st.st_mode)) { + ssize_t len; + strbuf_reset(&symlink); + + if (num_symlinks++ > MAXSYMLINKS) { + errno = ELOOP; - if (chdir(sb.buf)) { if (die_on_error) - die_errno("Could not switch to '%s'", - sb.buf); + die("More than %d nested symlinks " + "on path '%s'", MAXSYMLINKS, path); else goto error_out; } - } - if (strbuf_getcwd(&sb)) { - if (die_on_error) - die_errno("Could not get current working directory"); - else - goto error_out; - } - if (last_elem) { - if (sb.len && !is_dir_sep(sb.buf[sb.len - 1])) - strbuf_addch(&sb, '/'); - strbuf_addstr(&sb, last_elem); - free(last_elem); - last_elem = NULL; - } - - if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) { - struct strbuf next_sb = STRBUF_INIT; - ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0); + len = strbuf_readlink(&symlink, resolved->buf, + st.st_size); if (len < 0) { if (die_on_error) die_errno("Invalid symlink '%s'", - sb.buf); + resolved->buf); else goto error_out; } - strbuf_swap(&sb, &next_sb); - strbuf_release(&next_sb); - } else - break; + + if (is_absolute_path(symlink.buf)) { + /* absolute symlink; set resolved to root */ + get_root_part(resolved, &symlink); + } else { + /* + * relative symlink + * strip off the last component since it will + * be replaced with the contents of the symlink + */ + strip_last_component(resolved); + } + + /* + * if there are still remaining components to resolve + * then append them to symlink + */ + if (remaining.len) { + strbuf_addch(&symlink, '/'); + strbuf_addbuf(&symlink, &remaining); + } + + /* + * use the symlink as the remaining components that + * need to be resloved + */ + strbuf_swap(&symlink, &remaining); + } } - retval = sb.buf; + retval = resolved->buf; + error_out: - free(last_elem); - if (cwd.len && chdir(cwd.buf)) - die_errno("Could not change back to '%s'", cwd.buf); - strbuf_release(&cwd); + strbuf_release(&remaining); + strbuf_release(&next); + strbuf_release(&symlink); + + if (!retval) + strbuf_reset(resolved); return retval; } const char *real_path(const char *path) { - return real_path_internal(path, 1); + static struct strbuf realpath = STRBUF_INIT; + return strbuf_realpath(&realpath, path, 1); } const char *real_path_if_valid(const char *path) { - return real_path_internal(path, 0); + static struct strbuf realpath = STRBUF_INIT; + return strbuf_realpath(&realpath, path, 0); +} + +char *real_pathdup(const char *path, int die_on_error) +{ + struct strbuf realpath = STRBUF_INIT; + char *retval = NULL; + + if (strbuf_realpath(&realpath, path, die_on_error)) + retval = strbuf_detach(&realpath, NULL); + + strbuf_release(&realpath); + + return retval; } /* @@ -152,6 +239,13 @@ const char *absolute_path(const char *path) return sb.buf; } +char *absolute_pathdup(const char *path) +{ + struct strbuf sb = STRBUF_INIT; + strbuf_add_absolute_path(&sb, path); + return strbuf_detach(&sb, NULL); +} + /* * Unlike prefix_path, this should be used if the named file does * not have to interact with index entry; i.e. name of a random file |