usr/src/usr.bin/window/var.c

#ifndef lint
static char sccsid[] = "@(#)var.c       3.8 %G%";
#endif

/*
 * Copyright (c) 1983 Regents of the University of California,
 * All rights reserved.  Redistribution permitted subject to
 * the terms of the Berkeley Software License Agreement.
 */

#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;
}