diff options
Diffstat (limited to 'path.c')
| -rw-r--r-- | path.c | 160 |
1 files changed, 119 insertions, 41 deletions
@@ -363,56 +363,97 @@ const char *make_relative_path(const char *abs, const char *base) } /* - * path = absolute path - * buf = buffer of at least max(2, strlen(path)+1) bytes - * It is okay if buf == path, but they should not overlap otherwise. + * It is okay if dst == src, but they should not overlap otherwise. * - * Performs the following normalizations on path, storing the result in buf: - * - Removes trailing slashes. - * - Removes empty components. + * Performs the following normalizations on src, storing the result in dst: + * - Ensures that components are separated by '/' (Windows only) + * - Squashes sequences of '/'. * - Removes "." components. * - Removes ".." components, and the components the precede them. - * "" and paths that contain only slashes are normalized to "/". - * Returns the length of the output. + * Returns failure (non-zero) if a ".." component appears as first path + * component anytime during the normalization. Otherwise, returns success (0). * * Note that this function is purely textual. It does not follow symlinks, * verify the existence of the path, or make any system calls. */ -int normalize_absolute_path(char *buf, const char *path) +int normalize_path_copy(char *dst, const char *src) { - const char *comp_start = path, *comp_end = path; - char *dst = buf; - int comp_len; - assert(buf); - assert(path); - - while (*comp_start) { - assert(*comp_start == '/'); - while (*++comp_end && *comp_end != '/') - ; /* nothing */ - comp_len = comp_end - comp_start; - - if (!strncmp("/", comp_start, comp_len) || - !strncmp("/.", comp_start, comp_len)) - goto next; - - if (!strncmp("/..", comp_start, comp_len)) { - while (dst > buf && *--dst != '/') - ; /* nothing */ - goto next; - } + char *dst0; - memmove(dst, comp_start, comp_len); - dst += comp_len; - next: - comp_start = comp_end; + if (has_dos_drive_prefix(src)) { + *dst++ = *src++; + *dst++ = *src++; } + dst0 = dst; - if (dst == buf) + if (is_dir_sep(*src)) { *dst++ = '/'; + while (is_dir_sep(*src)) + src++; + } + for (;;) { + char c = *src; + + /* + * A path component that begins with . could be + * special: + * (1) "." and ends -- ignore and terminate. + * (2) "./" -- ignore them, eat slash and continue. + * (3) ".." and ends -- strip one and terminate. + * (4) "../" -- strip one, eat slash and continue. + */ + if (c == '.') { + if (!src[1]) { + /* (1) */ + src++; + } else if (is_dir_sep(src[1])) { + /* (2) */ + src += 2; + while (is_dir_sep(*src)) + src++; + continue; + } else if (src[1] == '.') { + if (!src[2]) { + /* (3) */ + src += 2; + goto up_one; + } else if (is_dir_sep(src[2])) { + /* (4) */ + src += 3; + while (is_dir_sep(*src)) + src++; + goto up_one; + } + } + } + + /* copy up to the next '/', and eat all '/' */ + while ((c = *src++) != '\0' && !is_dir_sep(c)) + *dst++ = c; + if (is_dir_sep(c)) { + *dst++ = '/'; + while (is_dir_sep(c)) + c = *src++; + src--; + } else if (!c) + break; + continue; + + up_one: + /* + * dst0..dst is prefix portion, and dst[-1] is '/'; + * go up one level. + */ + dst--; /* go to trailing '/' */ + if (dst <= dst0) + return -1; + /* Windows: dst[-1] cannot be backslash anymore */ + while (dst0 < dst && dst[-1] != '/') + dst--; + } *dst = '\0'; - return dst - buf; + return 0; } /* @@ -438,15 +479,16 @@ int longest_ancestor_length(const char *path, const char *prefix_list) return -1; for (colon = ceil = prefix_list; *colon; ceil = colon+1) { - for (colon = ceil; *colon && *colon != ':'; colon++); + for (colon = ceil; *colon && *colon != PATH_SEP; colon++); len = colon - ceil; if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil)) continue; strlcpy(buf, ceil, len+1); - len = normalize_absolute_path(buf, buf); - /* Strip "trailing slashes" from "/". */ - if (len == 1) - len = 0; + if (normalize_path_copy(buf, buf) < 0) + continue; + len = strlen(buf); + if (len > 0 && buf[len-1] == '/') + buf[--len] = '\0'; if (!strncmp(path, buf, len) && path[len] == '/' && @@ -457,3 +499,39 @@ int longest_ancestor_length(const char *path, const char *prefix_list) return max_len; } + +/* strip arbitrary amount of directory separators at end of path */ +static inline int chomp_trailing_dir_sep(const char *path, int len) +{ + while (len && is_dir_sep(path[len - 1])) + len--; + return len; +} + +/* + * If path ends with suffix (complete path components), returns the + * part before suffix (sans trailing directory separators). + * Otherwise returns NULL. + */ +char *strip_path_suffix(const char *path, const char *suffix) +{ + int path_len = strlen(path), suffix_len = strlen(suffix); + + while (suffix_len) { + if (!path_len) + return NULL; + + if (is_dir_sep(path[path_len - 1])) { + if (!is_dir_sep(suffix[suffix_len - 1])) + return NULL; + path_len = chomp_trailing_dir_sep(path, path_len); + suffix_len = chomp_trailing_dir_sep(suffix, suffix_len); + } + else if (path[--path_len] != suffix[--suffix_len]) + return NULL; + } + + if (path_len && !is_dir_sep(path[path_len - 1])) + return NULL; + return xstrndup(path, chomp_trailing_dir_sep(path, path_len)); +} |