Subject: Re: 4GL "replace" function
Date: Fri, 11 May 2001 16:23:08 -0700 (PDT)
From: Jonathan Leffler <jleffler@informix.com>
To: IIUG Software Archive <software@iiug.org>,
     Informix NewsGroup <informix-list@iiug.org>

On Fri, 11 May 2001, Ed Brown wrote:

>Has anyone ever coded/seen/used a C-code function for 4GL that can replace
>text within a string? Something like:
>
>LET string1 = REPLACE (source_string, search_for, replace_with)
>
>so that:
>
>LET string1 = REPLACE ("ABCDEFG", "CD", "XYZ")
>
>would result in string1 having a value of "ABXYZEFG"
>
>I looked on the IIUG site and didn't see anything in the software
repository
>there.

The attachment contains a global search and replace I wrote and used a
long time ago.  It translates "ABCDEFGCDHIJKLCDMN" to
"ABXYZEFGXYZHIJKLXYZMN", and apart from the name matches your calling
semantics.

It's still in K&R C because it pre-dates the original C standard.
However, I see that the compiler I used did have some support for
'void'.  That was probably on SCO Xenix.

--
Yours,
Jonathan Leffler (Jonathan.Leffler@Informix.com) #include <disclaimer.h>
Guardian of DBD::Informix v1.00.PC1 -- http://www.perl.com/CPAN
     "I don't suffer from insanity; I enjoy every minute of it!"

/*
@(#)    File:           $RCSfile: editstr.c,v $
@(#)    Version:        $Revision: 1.1 $
@(#)    Last changed:   $Date: 1988/10/03 13:22:18 $
@(#)    Purpose:        I4GL: Globally substitute substring in string
@(#)    Author:         J Leffler
*/

/* edit_string: globally substitute for a substring in a string */
/* I4GL: LET new_string = edit_string(old_string, sub, rep) */

int edit_string(i)
int i;
{
    char    old[512];
    char    new[512];
    char    sub[32];
    char    rep[32];
    char    *src;
    char    *dst;
    char    *s;
    char    *t;
    int     l_rep;
    int     l_sub;
    extern char *strpat();
    extern char *strn_cat();

    if (i != 3)
    {
        retquote("");
        return(1);
    }
    popstring(rep, sizeof(rep));
    popstring(sub, sizeof(sub));
    popstring(old, sizeof(old));
    dst = new;
    src = old;
    l_sub = strlen(sub);

    *dst = '\0';
    while ((s = strpat(src, sub)) != 0)
    {
        dst = strn_cat(dst, src, s-src+1);
        dst = strn_cat(dst, rep);
        src = s + l_sub;
    }
    (void)strn_cat(dst, src, sizeof(new));  /* tack on tail string */

    retquote(new);
    return(1);
}

static  char    *strn_cat(d, s, n)
register char   *d;     /* Out: string to be appended to */
register char   *s;     /* In:  string to append */
register int     n;     /* In:  maximum characters to copy */
{
    while (*d)
        d++;
    while (*s && --n > 0)
        *d++ = *s++;
    *d = '\0';
    return(d);
}

static  char    *strpat(s, p)
register char   *s;     /* In: string to search */
register char   *p;     /* In: string to search for */
{
    char    *t;
    register char c;
    char *u;

    c = *p;
    while (*s)
    {
        if (*s == c)
        {
            t = s;
            u = p;
            while (*u && *u++ == *t++)
                ;
            if (*u == '\0')
                return(s);  /* match found */
        }
        s++;
    }
    return(0); /* no match */
}