/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984 AT&T */
/*        All Rights Reserved   */

#pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.1 */

/*LINTLIBRARY*/
#include <stdio.h>
#include <string.h>

#define max(A,B) (((A)<(B))?(B):(A))

extern char *malloc(), *getenv(), *mktemp();
extern int access();

static char *pcopy();
static char seed[4];

char *
tempnam(dir, pfx)
char *dir;		/* use this directory please (if non-NULL) */
char *pfx;		/* use this (if non-NULL) as filename prefix */
{
	register char *p, *q, *tdir;
	int x=0, y=0, z;

	if (seed[0] == 0)
		seed[0] = seed[1] = seed[2] = 'A';
	z=strlen(P_tmpdir);
	if((tdir = getenv("TMPDIR")) != NULL) {
		x = strlen(tdir);
	}
	if(dir != NULL) {
		y=strlen(dir);
	}
	if((p=malloc((unsigned)(max(max(x,y),z)+16))) == NULL)
		return(NULL);
	if(x > 0 && access(pcopy(p, tdir), 3) == 0)
		goto OK;
	if(y > 0 && access(pcopy(p, dir), 3) == 0)
		goto OK;
	if(access(pcopy(p, P_tmpdir), 3) == 0)
		goto OK;
	if(access(pcopy(p, "/tmp"), 3) != 0)
		return(NULL);
OK:
	(void)strcat(p, "/");
	if(pfx) {
		*(p+strlen(p)+5) = '\0';
		(void)strncat(p, pfx, 5);
	}
	(void)strcat(p, seed);
	(void)strcat(p, "XXXXXX");
	q = seed;
	while(*q == 'Z')
		*q++ = 'A';
	++*q;
	if(*mktemp(p) == '\0')
		return(NULL);
	return(p);
}

static char*
pcopy(space, arg)
char *space, *arg;
{
	char *p;

	if(arg) {
		(void)strcpy(space, arg);
		p = space-1+strlen(space);
		if(*p == '/')
			*p = '\0';
	}
	return(space);
}