stdio/common/tempnam.c

/*
 * 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);
}