String splitting function

[Mark Denham]

By popular demand,

here is the string splitting function that I use.

Usage
call split_string(src, delim, return, strict) returning stat, str1..strn

src - Is string to split, max 5k
delim - Field separator
return - No. of strings to return (max).
strict - Set status to -ve value if the no. of strings in src is not the
same as return.

Note: Get rid of any bugs yourself! Only kidding.

Mark Denham
BBC
London, UK
Mark....@bbc.co.uk

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/* c source *}
{*************************************************************************
*
* $Author$
*
* $Date$
*
* $Revision$
*
* Doc Refs:
*
* Purpose: Allows an RDS program to split a string using a delimiter
* given by the user.
*
* Usage: split_string string String to split.
* delimiter Delimiter string.
* returns Max no. of strings to return.
* When there are less strings in
* source than returns and strict is
* FALSE, null strings are returned
* for the remaining values.
* strict If set causes the routine to return
* a failure status if the number of
* elements in string does not match
* the number specified by returns.
*
* where:
*
* string char[5120] Null terminated string to split.
* delimiter char[10] Null terminated delimiter string.
* returns smallint Max. no. of strings to return.
* strict integer TRUE/FALSE. Causes function to
* fail when no. of strings found
* does not match returns.
*
* Returns: stat integer 0 for ok, -ve as below:
* -1 = Too few strings in source
* -2 = retcnt > MAX_STRINGS
* -3 = Source contains more strs
* str[0..n] string As many strings as required.
*
* Library
* Functions:
*
* Notes: WHEN USING RDS.
* This function is MUST be linked with the RDS runner and debugger
* using the cfglgo and cfgldb commands. Refer to the Interactive
* debugger manual for details.
* If you have a NULL value separated by 2 delimiters,
* fred||john|...
* This routine will not produce the result you expect!
*
* Modification Log
*============================================================================
*
* $Log$
*
****************************************************************************
*}
/*

*/

int dummy_string_split() {

static char *rcsid = "@(#)$Header: $";

}

#include <stdio.h>
#include <stdlib.h>

#define MAX_STRINGS 320

#define MAX_DELIM_LEN 10

#define MAX_STR_SIZE 5120

int split_string(numargs)
int numargs;
{
char *strtok();

char src_string[MAX_STR_SIZE+1];

char delim[MAX_DELIM_LEN+1];

char *strlist[MAX_STRINGS];

char *nullstr = "",
*str;

int strict = 0,
retcnt = 0,
rval = 0,
stat = 0,
curridx = 0,
idx = 0;

if( numargs != 4 ) { /* This is a problem and cannot easily */
rval=-1; /* 4GL will most likely produce an error*/
retint(rval); /* indicating that the no. of returned */
return(1); /* values is incorrect....*/
}

/* Read parameter list */

popint(&strict);
popint(&retcnt);
popvchar(delim, MAX_DELIM_LEN);
popvchar(src_string, MAX_STR_SIZE);

/* Check that the no. strings required does not exceed max allowed */

if( retcnt <= MAX_STRINGS ) {
str = src_string;

/* Split up string, fail if srtict and end of source string reached */

for(; curridx < retcnt; curridx++) {
strlist[curridx] = strtok(str, delim);
str = NULL;
if( strict && strlist[curridx] == NULL ) {
rval = -1;
break;
}
}
}
else
rval = -2;

if( rval == 0 ) {
if( strict ) {
/* See if the source string is empty, if not fail */

if(strtok(str, delim) != NULL )
rval = -3;
}
}

/* Return extraction status */

retint(rval);

/* Return all filled in values, may help debugging when an error occurs */

for(idx=0; idx < curridx; idx++ ) {
retvchar(strlist[idx]);
}

/* Now do rest of strings, if any */

while(idx < retcnt) {
retvchar(nullstr);
idx++;
}

return(idx+1);
}