unget.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 294 行

#ifndef lint
static	char	*sccsid = "@(#)unget.c	4.1	(ULTRIX)	7/17/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1988, 1989 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.	*
 *									*
 ************************************************************************/
/*
 *
 * Modification history:
 *
 * 12-Jun-89 -- Ken Lesniak
 *	Modified "sact" to print a friendly message for files which
 *	are not currently reserved.
 *
 * 28 Jun 88 -- D. Long
 *	Use atomic rename operation in xremove instead of link and unlink.
 *	Also do error checking on fputs, fflush, and fclose's.
 */
# include	"../hdr/defines.h"
# include	"../hdr/had.h"


/*
		Program can be invoked as either "unget" or
		"sact".  Sact simply displays the p-file on the
		standard output.  Unget removes a specified entry
		from the p-file.
*/

struct stat Statbuf;
char Error[128];

int	verbosity;
int	num_files;
int	cmd;
long	Szqfile;
char	had[26];
char	Pfilename[FILESIZE];
char	*auxf();
struct	packet gpkt;
struct	sid sid;

main(argc,argv)
int argc;
char *argv[];
{
	int	i, testmore;
	char	c, *p;
	char	*sid_ab();
	extern	unget();
	extern	int Fcnt;

	Fflags = FTLEXIT | FTLMSG | FTLCLN;

	for(i=1; i<argc; i++)
		if(argv[i][0] == '-' && (c=argv[i][1])) {
			p = &argv[i][2];
			testmore = 0;
			switch (c) {

			case 'r':
				if (!p[0]) {
					argv[i] = 0;
					continue;
				}
				chksid(sid_ab(p,&sid),&sid);
				break;
			case 'n':
			case 's':
				testmore++;
				break;
			default:
				fatal("unknown key letter (cm1)");
			}

			if (testmore) {
				testmore = 0;
				if (*p) {
					sprintf(Error,
						"value after %c arg (cm7)",c);
					fatal(Error);
				}
			}
			if (had[c - 'a']++)
				fatal("key letter twice (cm2)");
			argv[i] = 0;
		}
		else num_files++;

	if(num_files == 0)
		fatal("missing file arg (cm3)");

	/*	If envoked as "sact", set flag
		otherwise executed as "unget".
	*/
	if (equal(sname(argv[0]),"sact")) {
		cmd = 1;
		HADS = 0;
	}

	if (!HADS)
		verbosity = -1;
	setsig();
	Fflags &= ~FTLEXIT;
	Fflags |= FTLJMP;
	for (i=1; i<argc; i++)
		if (p=argv[i])
			do_file(p,unget);
	exit(Fcnt ? 1 : 0);
}


unget(file)
char *file;
{
	extern	char had_dir, had_standinp;
	extern	char *Sflags[];
	int	i, status;
	char	gfilename[FILESIZE];
	char	str[BUFSIZ];
	char	*sid_ba();
	struct	pfile *pp, *edpfile();

	if (setjmp(Fjmp))
		return;

	/*	Initialize packet, but do not open SCCS file.
	*/
	sinit(&gpkt,file,0);
	gpkt.p_stdout = stdout;
	gpkt.p_verbose = verbosity;

	copy(auxf(gpkt.p_file,'g'),gfilename);
	if (gpkt.p_verbose && (num_files > 1 || had_dir || had_standinp))
		fprintf(gpkt.p_stdout,"\n%s:\n",gpkt.p_file);
	/*	If envoked as "sact", call catpfile() and return.
	*/
	if (cmd) {
		catpfile(&gpkt);
		return;
	}

	if (lockit(auxf(gpkt.p_file,'z'),2,getpid()))
		fatal("cannot create lock file (cm4)");
	pp = edpfile(&gpkt,&sid);
	if (gpkt.p_verbose) {
		sid_ba(&pp->pf_nsid,str);
		fprintf(gpkt.p_stdout,"%s\n",str);
	}

	/*	If the size of the q-file is greater than zero,
		rename the q-file the p-file and remove the
		old p-file; else remove both the q-file and
		the p-file.
	*/
	if (Szqfile)
		xrename(auxf(gpkt.p_file,'q'),Pfilename);
	else {
		xunlink(Pfilename);
		xunlink(auxf(gpkt.p_file,'q'));
	}
	ffreeall();
	unlockit(auxf(gpkt.p_file,'z'),getpid());

	/*	A child is spawned to remove the g-file so that
		the current ID will not be lost.
	*/
	if (!HADN) {
		if ((i = fork()) < 0)
			fatal("cannot fork, try again");
		if (i == 0) {
			setuid(getuid());
			unlink(gfilename);
			exit(0);
		}
		else {
			wait(&status);
		}
	}
}


struct pfile *
edpfile(pkt,sp)
struct packet *pkt;
struct sid *sp;
{
	static	struct pfile goodpf;
	char	*user, *logname();
	char	line[BUFSIZ];
	struct	pfile pf;
	int	cnt, name;
	FILE	*in, *out, *fdfopen();

	cnt = -1;
	name = 0;
	user = logname();
	zero(&goodpf,sizeof(goodpf));
	in = xfopen(auxf(pkt->p_file,'p'),0);
	out = xfcreat(auxf(pkt->p_file,'q'),0644);
	while (fgets(line,sizeof(line),in) != NULL) {
		pf_ab(line,&pf,1);
		if (equal(pf.pf_user,user)) {
			name++;
			if (sp->s_rel == 0) {
				if (++cnt) {
					fclose(out);
					fclose(in);
					fatal("SID must be specified (un1)");
				}
				goodpf = pf;
				continue;
			}
			else if (sp->s_rel == pf.pf_nsid.s_rel &&
				sp->s_lev == pf.pf_nsid.s_lev &&
				sp->s_br == pf.pf_nsid.s_br &&
				sp->s_seq == pf.pf_nsid.s_seq) {
					goodpf = pf;
					continue;
			}
		}
		fputs(line,out);
		if(ferror(out))
			FAILPUT;
	}
	if(fflush(out)==EOF)
		FAILPUT;
	fstat(fileno(out),&Statbuf);
	Szqfile = Statbuf.st_size;
	copy(auxf(pkt->p_file,'p'),Pfilename);
	fclose(out);
	fclose(in);
	if (!goodpf.pf_user[0])
		if (!name)
			fatal("login name not in p-file (un2)");
		else fatal("specified SID not in p-file (un3)");
	return(&goodpf);
}


/* clean_up() only called from fatal().
*/
clean_up(n)
{
	/*	Lockfile and q-file only removed if lockfile
		was created by this process.
	*/
	if (mylock(auxf(gpkt.p_file,'z'),getpid())) {
		unlink(auxf(gpkt.p_file,'q'));
		ffreeall();
		unlockit(auxf(gpkt.p_file,'z'),getpid());
	}
}

catpfile(pkt)
struct packet *pkt;
{
	int c;
	FILE *in;

	if(!(in = fopen(auxf(pkt->p_file,'p'),"r")))
		fprintf(stderr,"No outstanding deltas for: %s\n",pkt->p_file);
	else {
		while ((c = getc(in)) != EOF)
			putc(c,pkt->p_stdout);
		fclose(in);
	}
}