Re: [RFC] stick: Allowing you to extract some field from a string

[Willy Tarreau]

On Fri, Oct 31, 2014 at 11:56:08AM +0100, Emeric Brun wrote:
> In your case, you don't need to modify data so i think the most 
> elegant(zerocopy) way to do this converter is to not use smp_dup:
> 
> You only need to do a manual parsing to reach your token based on string 
> length and not char '0'. You only need to make smp->data.str.str point 
> on the start of the wanted field, and to set smp->data.str.len to the 
> appropriate value.

Absolutely. The following simple code works fine and does not touch the
input contents, feel free to adapt it to work with args and chunks :

void field(const char *str, int f, const char *sep, const char **beg, int *len)
{
        const char *s;
        const char *end;

        while (*str) {
                /* look for first character not a delimiter */
                for (s = sep; *s; s++) {
                        if (*str == *s)
                                goto next_delim;
                }

                /* look for first delimiter */
                for (end = str + 1; *end; end++) {
                        for (s = sep; *s; s++)  {
                                if (*end == *s)
                                        goto first_delim;
                        }
                }
        first_delim:
                /* we have the word between <str> and <end> */
                if (--f <= 0) {
                        *beg = str;
                        *len = (end - str);
                        return;
                }
                str = end;
        next_delim:
                str++;
        }
        *beg = NULL;
        *len = 0;
}

Regards,
Willy