Return to find.c CVS log

Up to [CSRG BSD Unix] / 43BSD / contrib / icon / functions

Annotation of 43BSD/contrib/icon/functions/find.c, revision 1.1.1.1

1.1       root        1: #include "../h/rt.h"
                      2: 
                      3: /*
                      4:  * find(s1,s2,i,j) - find string s1 in s2[i:j] and return position in
                      5:  *  s2 of beginning of s1.
                      6:  * Generates successive positions.
                      7:  */
                      8: 
                      9: Xfind(nargs, arg4, arg3, arg2, arg1, arg0)
                     10: int nargs;
                     11: struct descrip arg4, arg3, arg2, arg1, arg0;
                     12:    {
                     13:    register int l;
                     14:    register char *s1, *s2;
                     15:    int i, j, t;
                     16:    long l1, l2;
                     17:    char sbuf1[MAXSTRING], sbuf2[MAXSTRING];
                     18: 
                     19:    /*
                     20:     * s1 must be a string.  s2 defaults to &subject; i defaults to &pos
                     21:     *  if s defaulted, 1 otherwise;  j defaults to 0.
                     22:     */
                     23:    if (cvstr(&arg1, sbuf1) == NULL)
                     24:       runerr(103, &arg1);
                     25:    if (defstr(&arg2, sbuf2, &k_subject))
                     26:       defint(&arg3, &l1, k_pos);
                     27:    else
                     28:       defint(&arg3, &l1, 1);
                     29:    defint(&arg4, &l2, 0);
                     30: 
                     31:    /*
                     32:     * Convert i and j to absolute positions in s2 and order them so i <= j.
                     33:     */
                     34:    i = cvpos(l1, STRLEN(arg2));
                     35:    j = cvpos(l2, STRLEN(arg2));
                     36:    if (i > j) {
                     37:       t = i;
                     38:       i = j;
                     39:       j = t;
                     40:       }
                     41: 
                     42:    /*
                     43:     * Loop through s2[i:j] trying to find s1 at each point, stopping
                     44:     *  when the remaining portion s2[i:j] is too short to contain s1.
                     45:     */
                     46:    while (i <= j - STRLEN(arg1)) {
                     47:       s1 = STRLOC(arg1);
                     48:       s2 = STRLOC(arg2) + i - 1;
                     49:       l = STRLEN(arg1);
                     50:       /*
                     51:        * Compare strings on bytewise basis; if end is reached before
                     52:        *  inequality is found, suspend the position of the string.
                     53:        */
                     54:       do {
                     55:          if (l-- <= 0) {
                     56:             arg0.type = D_INTEGER;
                     57:             INTVAL(arg0) = i;
                     58:             suspend();
                     59:             break;
                     60:             }
                     61:          } while (*s1++ == *s2++);
                     62:       i++;
                     63:       }
                     64: 
                     65:    fail();
                     66:    }
                     67: 
                     68: Procblock(find,4)

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.