#include "cp_types.h"
#include "cp_proto.h"

/* return string between start_char and end_char. NULL means none found. */

char *pair_picking(char *datastr,char start_char,char end_char,char **endptr)
{
  int n=0,m=0;
  char *expression;

  while (*(datastr+n)!='\0' 
	 && *(datastr+n)!=start_char) n++;
  if (*(datastr+n)=='\0') /* no start_char */
    { *endptr=datastr; return NULL;}
  n++;
  while (*(datastr+n+m)!='\0'
	 && *(datastr+n+m)!=end_char) m++;
  if (*(datastr+n+m)=='\0') /* no end_char */
    { *endptr=datastr+n; return NULL;}
  if (m==0) /* empty string */
    { *endptr=datastr+n+1;return NULL;}
  if (m>1023) /* too big */
    { *endptr=datastr+n-1;return NULL;}
  expression=(char *)malloc((m+1)*sizeof(char));
  strncpy(expression,datastr+n,m);
  *(expression+m)='\0';
  *endptr=datastr+n+m+1;
  return expression;
} /* pair_picking */