Re: Convert native character string to ASCII array of integers

Tomás Ó hÉilidhe said:

<snip>

Please my MakeASCII function! Rip it apart!

Well, I won't rip it apart, but I think I can let a little air out of it.

#include <string.h>

void MakeASCII(unsigned char *pos,char const *pc)
{
const char *bcs =
" !\"#$%&'()*+,-./0123456789:;<=>?@"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"[\\]^_`"
"abcdefghijklmnopqrstuvwxyz"
"{|}~";
const char *cur = NULL;

while(*pc != '\0')
{
cur = strchr(bcs, *pc);
if(cur != NULL)
{
*pos++ = (cur - bcs) + 32;
}
else
{
*pos++ = *pc;
}
++pc;
}
*pos = '\0';
}

If you hit performance issues with that one, consider this alternative:

#include <string.h>
#include <limits.h>

void MakeASCII(unsigned char *pos,char const *pc)
{
const char *bcs =
" !\"#$%&'()*+,-./0123456789:;<=>?@"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"[\\]^_`"
"abcdefghijklmnopqrstuvwxyz"
"{|}~";
static char att[UCHAR_MAX + 1] = {0};

const char *cur = bcs;
int i = 0;

if(att[' '] != 32) /* do we need to set up the array? */
{
/* defaults */
for(i = 0; i < UCHAR_MAX + 1; i++)
{
att[i] = (char)i;
}

/* known ASCII characters */
i = 32;
while(*cur != '\0')
{
att[*cur++] = i++;
}
}

while(*pos++ = att[*pc++])
{
continue;
}
}


--
Richard Heathfield <http://www.cpax.org.uk>
Email: -http://www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999
.

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