Return to mksubs.c CVS log

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

Annotation of 43BSD/contrib/icon/rt/mksubs.c, revision 1.1

1.1     ! root        1: #include "../h/rt.h"
        !             2: 
        !             3: /*
        !             4:  * mksubs - form a substring.  var is a descriptor for the string from
        !             5:  *  which the substring is to be formed.  var may be a variable.  val
        !             6:  *  is a dereferenced version of val.  The descriptor for the resulting
        !             7:  *  substring is placed in *result.  The substring starts at position
        !             8:  *  i and extends for j characters.
        !             9:  */
        !            10: 
        !            11: struct descrip mksubs(var, val, i, j, result)
        !            12: register struct descrip *var, *val, *result;
        !            13: int i, j;
        !            14:    {
        !            15:    extern struct b_tvsubs *alcsubs();
        !            16: 
        !            17:    if (QUAL(*var) || !VAR(*var)) {
        !            18:       /*
        !            19:        * var isn't a variable, just form a descriptor that points into
        !            20:        *  the string named by val.
        !            21:        */
        !            22:       STRLEN(*result) = j;
        !            23:       STRLOC(*result) = STRLOC(*val) + i - 1;
        !            24:       return;
        !            25:       }
        !            26: 
        !            27:    if (TVAR(*var)) {
        !            28:       /*
        !            29:        * var is a trapped variable.  If it is a substring trapped variable,
        !            30:        *  adjust the position and make var the substrung string.  For other
        !            31:        *  trapped variables, don't do anything.
        !            32:        */
        !            33:       switch (TYPE(*var)) {
        !            34:          case T_TVSUBS:
        !            35:             i += BLKLOC(*var)->tvsubs.sspos - 1;
        !            36:             var = &BLKLOC(*var)->tvsubs.ssvar;
        !            37:             break;
        !            38: 
        !            39:          default:
        !            40:             break;
        !            41:          }
        !            42:       }
        !            43: 
        !            44:    /*
        !            45:     * Make a substring trapped variable by passing the buck to alcsubs.
        !            46:     */
        !            47:    result->type = D_TVSUBS;
        !            48:    BLKLOC(*result) = (union block *) alcsubs(j, i, var);
        !            49:    return;
        !            50:    }

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