mirror of
https://github.com/topjohnwu/ndk-busybox.git
synced 2024-12-13 06:25:46 +00:00
97 lines
1.9 KiB
C
97 lines
1.9 KiB
C
/* 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 "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)
|
|
{
|
|
/* 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;
|
|
const char *q;
|
|
unsigned num_digits;
|
|
unsigned r;
|
|
unsigned n;
|
|
unsigned d;
|
|
unsigned base;
|
|
|
|
num_digits = n = 0;
|
|
base = 8;
|
|
q = *ptr;
|
|
|
|
#ifdef WANT_HEX_ESCAPES
|
|
if (*q == 'x') {
|
|
++q;
|
|
base = 16;
|
|
++num_digits;
|
|
}
|
|
#endif
|
|
|
|
/* 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 {
|
|
d = (unsigned char)(*q) - '0';
|
|
#ifdef WANT_HEX_ESCAPES
|
|
if (d >= 10) {
|
|
d = (unsigned char)(_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);
|
|
/* p points to found escape char or NUL,
|
|
* advance it and find what it translates to */
|
|
p += sizeof(charmap) / 2;
|
|
n = *p;
|
|
}
|
|
|
|
*ptr = q;
|
|
|
|
return (char) n;
|
|
}
|