jehanne/sys/src/lib/jehanne/port/u16.c

63 lines
1.2 KiB
C

/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <libc.h>
static char t16e[] = "0123456789ABCDEF";
int
jehanne_dec16(uint8_t *out, int lim, const char *in, int n)
{
int c, w = 0, i = 0;
uint8_t *start = out;
uint8_t *eout = out + lim;
while(n-- > 0){
c = *in++;
if('0' <= c && c <= '9')
c = c - '0';
else if('a' <= c && c <= 'z')
c = c - 'a' + 10;
else if('A' <= c && c <= 'Z')
c = c - 'A' + 10;
else
continue;
w = (w<<4) + c;
i++;
if(i == 2){
if(out + 1 > eout)
goto exhausted;
*out++ = w;
w = 0;
i = 0;
}
}
exhausted:
return out - start;
}
int
jehanne_enc16(char *out, int lim, const uint8_t *in, int n)
{
uint32_t c;
char *eout = out + lim;
char *start = out;
while(n-- > 0){
c = *in++;
if(out + 2 >= eout)
goto exhausted;
*out++ = t16e[c>>4];
*out++ = t16e[c&0xf];
}
exhausted:
*out = 0;
return out - start;
}