mktemp.c

操作系统SunOS 4.1.3版本的源码

#if !defined(lint) && defined(SCCSIDS)
static	char sccsid[] = "@(#)mktemp.c 1.1 92/07/30 SMI"; /* from S5R3 1.11 */
#endif
/*	Copyright (c) 1984 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/

/*LINTLIBRARY*/
/****************************************************************
 *	Routine expects a string of length at least 6, with
 *	six trailing 'X's.  These will be overlaid with a
 *	letter and the last (5) digigts of the proccess ID.
 *	If every letter (a thru z) thus inserted leads to
 *	an existing file name, your string is shortened to
 *	length zero upon return (first character set to '\0').
 ***************************************************************/
#include <sys/types.h>
#include <sys/stat.h>

#define XCNT  6

extern int strlen(), access(), getpid();

char *
mktemp(as)
char *as;
{
	register char *s=as;
	register unsigned pid;
	register unsigned xcnt=0; /* keeps track of number of X's seen */
	struct stat buf;

	pid = getpid();
	s += strlen(as);	/* point at the terminal null */
	while(*--s == 'X' && ++xcnt <= XCNT) {
		*s = (pid%10) + '0';
		pid /= 10;
	}
	if(*++s) {		/* maybe there were no 'X's */
		*s = 'a';
		while (stat(as, &buf) == 0) {
			if(++*s > 'z') {
				*as = '\0';
				break;
			}
		}
	} else
		if (stat(as, &buf) == 0)
			*as = '\0';
	return(as);
}