4.3BSD - /usr/src/new/icon/operators/lexeq.c

   1: #include "../h/rt.h"
   2: 
   3: /*
   4:  * x == y - test if x is lexically equal to y.
   5:  */
   6: 
   7: lexeq(nargs, arg2, arg1, arg0)
   8: int nargs;
   9: struct descrip arg2, arg1, arg0;
  10:    {
  11:    DclSave
  12:    register int t, i;
  13:    register char *s1, *s2;
  14:    char sbuf1[MAXSTRING], sbuf2[MAXSTRING];
  15:    extern char *alcstr();
  16: 
  17:    SetBound;
  18:    /*
  19:     * x and y must be strings.  Save the cvstr return value for y because
  20:     *  y is the result (if any).
  21:     */
  22:    if (cvstr(&arg1, sbuf1) == NULL)
  23:       runerr(103, &arg1);
  24:    if ((t = cvstr(&arg2, sbuf2)) == NULL)
  25:       runerr(103, &arg2);
  26: 
  27:    /*
  28:     * If the strings have different lengths they can't be equal
  29:     */
  30:    if (STRLEN(arg1) != STRLEN(arg2))
  31:       fail();
  32: 
  33:    /*
  34:     * compare the strings
  35:     */
  36:    i = STRLEN(arg1);
  37:    s1 = STRLOC(arg1);
  38:    s2 = STRLOC(arg2);
  39:    while (i--)
  40:       if (*s1++ != *s2++)
  41:          fail();
  42: 
  43:    /*
  44:     * Return y as the result of the comparison.  If y was converted to
  45:     *  a string, a copy of it is allocated.
  46:     */
  47:    arg0 = arg2;
  48:    if (t == 1)
  49:       STRLOC(arg0) = alcstr(STRLOC(arg0), STRLEN(arg0));
  50:    ClearBound;
  51:    }
  52: 
  53: Opblock(lexeq,2,"==")

Defined functions