/* vi: set sw=4 ts=4: */ /* * Utility routines. * * Copyright (C) Manuel Novoa III <mjn3@codepoet.org> * and Vladimir Oleynik <dzo@simtreas.ru> * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #include <stdio.h> #include <limits.h> #include <ctype.h> #include "libbb.h" #define WANT_HEX_ESCAPES 1 /* Usual "this only works for ascii compatible encodings" disclaimer. */ #undef _tolower #define _tolower(X) ((X)|((char) 0x20)) char bb_process_escape_sequence(const char **ptr) { static const char charmap[] = { 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', 0, '\a', '\b', '\f', '\n', '\r', '\t', '\v', '\\', '\\' }; const char *p; const char *q; unsigned int num_digits; unsigned int r; unsigned int n; unsigned int d; unsigned int base; num_digits = n = 0; base = 8; q = *ptr; #ifdef WANT_HEX_ESCAPES if (*q == 'x') { ++q; base = 16; ++num_digits; } #endif do { d = (unsigned int)(*q - '0'); #ifdef WANT_HEX_ESCAPES if (d >= 10) { d = ((unsigned int)(_tolower(*q) - 'a')) + 10; } #endif if (d >= base) { #ifdef WANT_HEX_ESCAPES if ((base == 16) && (!--num_digits)) { /* return '\\'; */ --q; } #endif break; } r = n * base + d; if (r > UCHAR_MAX) { break; } n = r; ++q; } while (++num_digits < 3); if (num_digits == 0) { /* mnemonic escape sequence? */ p = charmap; do { if (*p == *q) { q++; break; } } while (*++p); n = *(p+(sizeof(charmap)/2)); } *ptr = q; return (char) n; }