first try at POSIX tty

[unix-history] / usr / src / usr.bin / window / var.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
static char sccsid[] = "@(#)var.c       3.10 (Berkeley) %G%";
#endif /* not lint */

#include "value.h"
#include "var.h"
#include "string.h"

char *malloc();

struct var *
var_set1(head, name, v)
struct var **head;
char *name;
struct value *v;
{
       register struct var **p;
       register struct var *r;
       struct value val;

       /* do this first, easier to recover */
       val = *v;
       if (val.v_type == V_STR && val.v_str != 0 &&
           (val.v_str = str_cpy(val.v_str)) == 0)
               return 0;
       if (*(p = var_lookup1(head, name)) == 0) {
               r = (struct var *) malloc(sizeof (struct var));
               if (r == 0) {
                       val_free(val);
                       return 0;
               }
               if ((r->r_name = str_cpy(name)) == 0) {
                       val_free(val);
                       free((char *) r);
                       return 0;
               }
               r->r_left = r->r_right = 0;
               *p = r;
       } else {
               r = *p;
               val_free(r->r_val);
       }
       r->r_val = val;
       return r;
}

struct var *
var_setstr1(head, name, str)
struct var **head;
char *name;
char *str;
{
       struct value v;

       v.v_type = V_STR;
       v.v_str = str;
       return var_set1(head, name, &v);
}

struct var *
var_setnum1(head, name, num)
struct var **head;
char *name;
int num;
{
       struct value v;

       v.v_type = V_NUM;
       v.v_num = num;
       return var_set1(head, name, &v);
}

var_unset1(head, name)
struct var **head;
char *name;
{
       register struct var **p;
       register struct var *r;

       if (*(p = var_lookup1(head, name)) == 0)
               return -1;
       r = *p;
       *p = r->r_left;
       while (*p != 0)
               p = &(*p)->r_right;
       *p = r->r_right;
       val_free(r->r_val);
       str_free(r->r_name);
       free((char *) r);
       return 0;
}

struct var **
var_lookup1(p, name)
register struct var **p;
register char *name;
{
       register cmp;

       while (*p != 0) {
               if ((cmp = strcmp(name, (*p)->r_name)) < 0)
                       p = &(*p)->r_left;
               else if (cmp > 0)
                       p = &(*p)->r_right;
               else
                       break;
       }
       return p;
}

var_walk1(r, func, a)
register struct var *r;
int (*func)();
{
       if (r == 0)
               return 0;
       if (var_walk1(r->r_left, func, a) < 0 || (*func)(a, r) < 0
           || var_walk1(r->r_right, func, a) < 0)
               return -1;
       return 0;
}