/* 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 source tree. */ #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 FAST_FUNC bb_process_escape_sequence(const char **ptr) { const char *q; unsigned num_digits; unsigned n; unsigned base; num_digits = n = 0; base = 8; q = *ptr; if (WANT_HEX_ESCAPES && *q == 'x') { ++q; base = 16; ++num_digits; } /* bash requires leading 0 in octal escapes: * \02 works, \2 does not (prints \ and 2). * We treat \2 as a valid octal escape sequence. */ do { unsigned r; unsigned d = (unsigned char)(*q) - '0'; #if WANT_HEX_ESCAPES if (d >= 10) { d = (unsigned char)_tolower(*q) - 'a'; //d += 10; /* The above would map 'A'-'F' and 'a'-'f' to 10-15, * however, some chars like '@' would map to 9 < base. * Do not allow that, map invalid chars to N > base: */ if ((int)d >= 0) d += 10; } #endif if (d >= base) { if (WANT_HEX_ESCAPES && base == 16) { --num_digits; if (num_digits == 0) { /* \x<bad_char>: return '\', * leave ptr pointing to x */ return '\\'; } } break; } r = n * base + d; if (r > UCHAR_MAX) { break; } n = r; ++q; } while (++num_digits < 3); if (num_digits == 0) { /* Not octal or hex escape sequence. * Is it one-letter one? */ /* bash builtin "echo -e '\ec'" interprets \e as ESC, * but coreutils "/bin/echo -e '\ec'" does not. * Manpages tend to support coreutils way. * Update: coreutils added support for \e on 28 Oct 2009. */ static const char charmap[] ALIGN1 = { 'a', 'b', 'e', 'f', 'n', 'r', 't', 'v', '\\', '\0', '\a', '\b', 27, '\f', '\n', '\r', '\t', '\v', '\\', '\\', }; const char *p = charmap; do { if (*p == *q) { q++; break; } } while (*++p != '\0'); /* p points to found escape char or NUL, * advance it and find what it translates to. * Note that \NUL and unrecognized sequence \z return '\' * and leave ptr pointing to NUL or z. */ n = p[sizeof(charmap) / 2]; } *ptr = q; return (char) n; } char* FAST_FUNC strcpy_and_process_escape_sequences(char *dst, const char *src) { while (1) { char c, c1; c = c1 = *src++; if (c1 == '\\') c1 = bb_process_escape_sequence(&src); *dst = c1; if (c == '\0') return dst; dst++; } }