diff options
| -rw-r--r-- | util.c | 323 | ||||
| -rw-r--r-- | util.h | 14 |
2 files changed, 337 insertions, 0 deletions
@@ -553,3 +553,326 @@ char hexchar(int x) { return table[x & 15]; } + +int unhexchar(char c) { + + if (c >= '0' && c <= '9') + return c - '0'; + + if (c >= 'a' && c <= 'f') + return c - 'a'; + + if (c >= 'A' && c <= 'F') + return c - 'A'; + + return -1; +} + +char octchar(int x) { + return '0' + (x & 7); +} + +int unoctchar(char c) { + + if (c >= '0' && c <= '7') + return c - '0'; + + return -1; +} + +char *cescape(const char *s) { + char *r, *t; + const char *f; + + assert(s); + + /* Does C style string escaping. */ + + if (!(r = new(char, strlen(s)*4 + 1))) + return NULL; + + for (f = s, t = r; *f; f++) + + switch (*f) { + + case '\a': + *(t++) = '\\'; + *(t++) = 'a'; + break; + case '\b': + *(t++) = '\\'; + *(t++) = 'b'; + break; + case '\f': + *(t++) = '\\'; + *(t++) = 'f'; + break; + case '\n': + *(t++) = '\\'; + *(t++) = 'n'; + break; + case '\r': + *(t++) = '\\'; + *(t++) = 'r'; + break; + case '\t': + *(t++) = '\\'; + *(t++) = 't'; + break; + case '\v': + *(t++) = '\\'; + *(t++) = 'v'; + break; + case '\\': + *(t++) = '\\'; + *(t++) = '\\'; + break; + case '"': + *(t++) = '\\'; + *(t++) = '"'; + break; + case '\'': + *(t++) = '\\'; + *(t++) = '\''; + break; + + default: + /* For special chars we prefer octal over + * hexadecimal encoding, simply because glib's + * g_strescape() does the same */ + if ((*f < ' ') || (*f >= 127)) { + *(t++) = '\\'; + *(t++) = octchar((unsigned char) *f >> 6); + *(t++) = octchar((unsigned char) *f >> 3); + *(t++) = octchar((unsigned char) *f); + } else + *(t++) = *f; + break; + } + + *t = 0; + + return r; +} + +char *cunescape(const char *s) { + char *r, *t; + const char *f; + + assert(s); + + /* Undoes C style string escaping */ + + if (!(r = new(char, strlen(s)+1))) + return r; + + for (f = s, t = r; *f; f++) { + + if (*f != '\\') { + *(t++) = *f; + continue; + } + + f++; + + switch (*f) { + + case 'a': + *(t++) = '\a'; + break; + case 'b': + *(t++) = '\b'; + break; + case 'f': + *(t++) = '\f'; + break; + case 'n': + *(t++) = '\n'; + break; + case 'r': + *(t++) = '\r'; + break; + case 't': + *(t++) = '\t'; + break; + case 'v': + *(t++) = '\v'; + break; + case '\\': + *(t++) = '\\'; + break; + case '"': + *(t++) = '"'; + break; + case '\'': + *(t++) = '\''; + break; + + case 'x': { + /* hexadecimal encoding */ + int a, b; + + if ((a = unhexchar(f[1])) < 0 || + (b = unhexchar(f[2])) < 0) { + /* Invalid escape code, let's take it literal then */ + *(t++) = '\\'; + *(t++) = 'x'; + } else { + *(t++) = (char) ((a << 4) | b); + f += 2; + } + + break; + } + + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': { + /* octal encoding */ + int a, b, c; + + if ((a = unoctchar(f[0])) < 0 || + (b = unoctchar(f[1])) < 0 || + (c = unoctchar(f[2])) < 0) { + /* Invalid escape code, let's take it literal then */ + *(t++) = '\\'; + *(t++) = f[0]; + } else { + *(t++) = (char) ((a << 6) | (b << 3) | c); + f += 2; + } + + break; + } + + case 0: + /* premature end of string.*/ + *(t++) = '\\'; + goto finish; + + default: + /* Invalid escape code, let's take it literal then */ + *(t++) = '\\'; + *(t++) = 'f'; + break; + } + } + +finish: + *t = 0; + return r; +} + + +char *xescape(const char *s, const char *bad) { + char *r, *t; + const char *f; + + /* Escapes all chars in bad, in addition to \ and all special + * chars, in \xFF style escaping. May be reversed with + * cunescape. */ + + if (!(r = new(char, strlen(s)*4+1))) + return NULL; + + for (f = s, t = r; *f; f++) { + + if (*f < ' ' || *f >= 127 || + *f == '\\' || strchr(bad, *f)) { + *(t++) = '\\'; + *(t++) = 'x'; + *(t++) = hexchar(*f >> 4); + *(t++) = hexchar(*f); + } else + *(t++) = *f; + } + + *t = 0; + + return r; +} + +char *path_kill_slashes(char *path) { + char *f, *t; + bool slash = false; + + /* Removes redundant inner and trailing slashes. Modifies the + * passed string in-place. + * + * ///foo///bar/ becomes /foo/bar + */ + + for (f = path, t = path; *f; f++) { + + if (*f == '/') { + slash = true; + continue; + } + + if (slash) { + slash = false; + *(t++) = '/'; + } + + *(t++) = *f; + } + + /* Special rule, if we are talking of the root directory, a + trailing slash is good */ + + if (t == path && slash) + *(t++) = '/'; + + *t = 0; + return path; +} + +bool path_startswith(const char *path, const char *prefix) { + assert(path); + assert(prefix); + + if ((path[0] == '/') != (prefix[0] == '/')) + return false; + + for (;;) { + size_t a, b; + + path += strspn(path, "/"); + prefix += strspn(prefix, "/"); + + if (*prefix == 0) + return true; + + if (*path == 0) + return false; + + a = strcspn(path, "/"); + b = strcspn(prefix, "/"); + + if (a != b) + return false; + + if (memcmp(path, prefix, a) != 0) + return false; + + path += a; + prefix += b; + } +} + +char *ascii_strlower(char *path) { + char *p; + + assert(path); + + for (p = path; *p; p++) + if (*p >= 'A' && *p <= 'Z') + *p = *p - 'A' + 'a'; + + return p; +} @@ -106,5 +106,19 @@ char *strstrip(char *s); char *file_in_same_dir(const char *path, const char *filename); char hexchar(int x); +int unhexchar(char c); +char octchar(int x); +int unoctchar(char c); + +char *cescape(const char *s); +char *cunescape(const char *s); + +char *path_kill_slashes(char *path); + +bool path_startswith(const char *path, const char *prefix); + +char *ascii_strlower(char *path); + +char *xescape(const char *s, const char *bad); #endif |