gnxseq.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char sccsid[] = "@(#)gnxseq.c	4.1 (decvax!larry) 7/2/90";
#endif

#include "uucp.h"
#include <sys/types.h>
#include <sys/time.h>

extern	time_t	time();



/*******
 *	gnxseq(rmtname)		get next conversation sequence number
 *	char *rmtname;
 *
 *	return - 0 no entry | >0 sequence number
 ********/

/*********
 *  Mods: 
 *	decvax!larry - return immediately if SQFILE does not exist.
 *
 *********/




/************************************************************************
 *									*
 *			Copyright (c) 1984 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/



gnxseq(rmtname)
char *rmtname;
{
	int count = 0, ct, ret, i;
	struct tm *tp;
	extern struct tm *localtime();
	time_t clock;
	FILE *fp0, *fp1;
	char buf[BUFSIZ], name[NAMESIZE];

	if ((fp0 = fopen(SQFILE, "r")) == NULL)
		return(0);
	if ((fp1 = fopen(SQTMP, "w")) == NULL) {
		fclose(fp0);
		return(0);
	}
	for (i = 0; i < 5; i++) {
		if ((ret = ulockf(SQLOCK, (time_t)  SQTIME)) == 0)
			break;
		sleep(5);
	}
	if (ret != 0) {
		logent("CAN'T LOCK", SQLOCK);
		DEBUG(4, "can't lock %s\n", SQLOCK);
		fclose(fp0);
		fclose(fp1);
		return(0);
	}
	chmod(SQTMP, 0400);

	while (fgets(buf, BUFSIZ, fp0) != NULL) {
		ret = sscanf(buf, "%s%d", name, &ct);
		if (ret < 2)
			ct = 0;
		name[7] = '\0';
		if (ct > 9998)
			ct = 0;
		if (strcmp(rmtname, name) != SAME) {
			fputs(buf, fp1);
			continue;
		}

		/*  found name  */
		count = ++ct;
		time(&clock);
		tp = localtime(&clock);
		fprintf(fp1, "%s %d %d/%d-%d:%02d\n", name, ct,
		  tp->tm_mon + 1, tp->tm_mday, tp->tm_hour,
		  tp->tm_min);
		while (fgets(buf, BUFSIZ, fp0) != NULL)
			fputs(buf, fp1);
	}
	fclose(fp0);
	fclose(fp1);
	if (count == 0) {
		rmlock(SQLOCK);
		unlink(SQTMP);
	}
	return(count);
}


/***
 *	cmtseq()	commit sequence update
 *
 *	return  0  ok | other - link failed
 */

cmtseq()
{
	int ret;

	if ((ret = access(SQTMP, 4)) != 0) {
		rmlock(SQLOCK);
		return(0);
	}
	unlink(SQFILE);
	ret = link(SQTMP, SQFILE);
	unlink(SQTMP);
	rmlock(SQLOCK);
	return(ret);
}

/***
 *	ulkseq()	unlock sequence file
 */

ulkseq()
{
	unlink(SQTMP);
	rmlock(SQLOCK);
}