NetBSD/usr.sbin/sup/source/scan.c

/*
 * Copyright (c) 1992 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software_Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 * scan.c - sup list file scanner
 *
 **********************************************************************
 * HISTORY
 * $Log: scan.c,v $
 * Revision 1.5  1996/09/05 16:50:04  christos
 * - for portability make sure that we never use "" as a pathname, always convert
 *   it to "."
 * - include sockio.h if needed to define SIOCGIFCONF (for svr4)
 * - use POSIX signals and wait macros
 * - add -S silent flag, so that the client does not print messages unless there
 *   is something wrong
 * - use flock or lockf as appropriate
 * - use fstatfs or fstatvfs to find out if a filesystem is mounted over nfs,
 *   don't depend on the major() = 255 hack; it only works on legacy systems.
 * - use gzip -cf to make sure that gzip compresses the file even when the file
 *   would expand.
 * - punt on defining vsnprintf if _IOSTRG is not defined; use sprintf...
 *
 * To compile sup on systems other than NetBSD, you'll need a copy of daemon.c,
 * vis.c, vis.h and sys/cdefs.h. Maybe we should keep those in the distribution?
 *
 * Revision 1.4  1995/10/29 23:54:45  christos
 * - runio fails when result != 0 not only < 0
 * - print vis-encoded file in the scanner.
 *
 * Revision 1.3  1995/06/24 16:21:42  christos
 * - Don't use system(3) to fork processes. It is a big security hole.
 * - Encode the filenames in the scan files using strvis(3), so filenames
 *   that contain newlines or other weird characters don't break the scanner.
 *
 * Revision 1.2  1994/01/03 14:47:25  brezak
 * Change <sys/dir.h> to <dirent.h>
 *
 * Revision 1.1.1.1  1993/05/21  14:52:17  cgd
 * initial import of CMU's SUP to NetBSD
 *
 * Revision 1.8  92/08/11  12:04:28  mrt
 * 	Brad's changes: delinted, added forward declarations of static
 * 	functions.Added Copyright.
 * 	[92/07/24            mrt]
 * 
 * 18-Mar-88  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added host=<hostfile> support to releases file.
 *
 * 11-Mar-88  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added "rsymlink" recursive symbolic link quoting directive.
 *
 * 28-Jun-87  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added code for "release" support.
 *
 * 26-May-87  Doug Philips (dwp) at Carnegie-Mellon University
 *	Lets see if we'll be able to write the scan file BEFORE
 *	we collect the data for it.  Include sys/file.h and use
 *	new definitions for access check codes.
 *
 * 20-May-87  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added type casting information for lint.
 *
 * 21-Jan-86  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added check for newonly upgrade when lasttime is the same as
 *	scantime.  This will save us the trouble of parsing the scanfile
 *	when the client has successfully received everything in the
 *	scanfile already.
 *
 * 16-Jan-86  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Clear Texec pointers in execT so that Tfree of execT will not
 *	free command trees associated with files in listT.
 *
 * 06-Jan-86  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added code to omit scanned files from list if we want new files
 *	only and they are old.
 *
 * 29-Dec-85  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Major rewrite for protocol version 4.  Added version numbers to
 *	scan file.  Also added mode of file in addition to flags.
 *	Execute commands are now immediately after file information.
 *
 * 13-Dec-85  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added comments to list file format.
 *
 * 08-Dec-85  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Added code to implement omitany.  Currently doesn't know about
 *	{a,b,c} patterns.
 *
 * 07-Oct-85  Glenn Marcy (gm0w) at Carnegie-Mellon University
 *	Created.
 *
 **********************************************************************
 */

#include <libc.h>
#include <c.h>
#include <vis.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#ifdef HAS_POSIX_DIR
#include <dirent.h>
#else
#include <sys/dir.h>
#endif
#include <sys/file.h>
#include <unistd.h>
#include "sup.h"

/*************************
 ***    M A C R O S    ***
 *************************/

#define SPECNUMBER 1000
	/* number of filenames produced by a single spec in the list file */

/*******************************************
 ***    D A T A   S T R U C T U R E S    ***
 *******************************************/

typedef enum {			/* release options */
	ONEXT,		OPREFIX,	OLIST,		OSCAN,
	OHOST
} OPTION;

static char *options[] = {
	"next",		"prefix",	"list",		"scan",
	"host",
	0
};

typedef enum {			/* <collection>/list file lines */
	LUPGRADE,	LOMIT,		LBACKUP,	LEXECUTE,
	LINCLUDE,	LNOACCT,	LOMITANY,	LALWAYS,
	LSYMLINK,	LRSYMLINK
} LISTTYPE;

static char *ltname[] = {
	"upgrade",	"omit",		"backup",	"execute",
	"include",	"noaccount",	"omitany",	"always",
	"symlink",	"rsymlink",
	0
};

#define FALWAYS		FUPDATE

/* list file lines */
static TREE *upgT;			/* files to upgrade */
static TREE *flagsT;			/* special flags: BACKUP NOACCT */
static TREE *omitT;			/* recursize file omition list */
static TREE *omanyT;			/* non-recursize file omition list */
static TREE *symT;			/* symbolic links to quote */
static TREE *rsymT;			/* recursive symbolic links to quote */
static TREE *execT;			/* execute command list */

/*************************
 ***    E X T E R N    ***
 *************************/

#ifdef	lint
static char _argbreak;
#else
extern char _argbreak;			/* break character from nxtarg */
#endif

extern TREELIST *listTL;		/* list of trees for scanning */
extern TREE *listT;			/* final list of files in collection */
extern TREE *refuseT;			/* files refused by client */

extern char *collname;			/* collection name */
extern char *basedir;			/* base directory name */
extern char *prefix;			/* collection pathname prefix */
extern long lasttime;			/* time of last upgrade */
extern long scantime;			/* time of this scan */
extern int trace;			/* trace directories */
extern int newonly;			/* new files only */

#ifdef RCSSTAT
extern char *rcs_branch;
extern int candorcs;
#endif

extern long time();

/*************************************************
 ***   STATIC   R O U T I N E S    ***
 *************************************************/

static makescan();
static getscan();
static doscan();
static readlistfile();
static expTinsert();
static listone();
static listentry();
static listname();
static listdir();
static omitanyone();
static anyglob();
static int getscanfile();
static chkscanfile();
static makescanfile();
static recordone();
static recordexec();

/*************************************************
 ***    L I S T   S C A N   R O U T I N E S    ***
 *************************************************/

static
passdelim (ptr,delim)		/* skip over delimiter */
char **ptr,delim;
{
	*ptr = skipover (*ptr, " \t");
	if (_argbreak != delim && **ptr == delim) {
		(*ptr)++;
		*ptr = skipover (*ptr, " \t");
	}
}

static
char *parserelease(tlp,relname,args)
TREELIST **tlp;
char *relname,*args;
{
	register TREELIST *tl;
	register char *arg;
	register OPTION option;
	int opno;
	char *nextrel;

	tl = (TREELIST *) malloc (sizeof(TREELIST));
	if ((*tlp = tl) == NULL)
		goaway ("Couldn't allocate TREELIST");
	tl->TLnext = NULL;
	tl->TLname = salloc (relname);
	tl->TLprefix = NULL;
	tl->TLlist = NULL;
	tl->TLscan = NULL;
	tl->TLhost = NULL;
	nextrel = NULL;
	args = skipover (args," \t");
	while (*(arg=nxtarg(&args," \t="))) {
		for (opno = 0; options[opno] != NULL; opno++)
			if (strcmp (arg,options[opno]) == 0)
				break;
		if (options[opno] == NULL)
			goaway ("Invalid release option %s for release %s",
				arg,relname);
		option = (OPTION) opno;
		switch (option) {
		case ONEXT:
			passdelim (&args,'=');
			arg = nxtarg (&args," \t");
			nextrel = salloc (arg);
			break;
		case OPREFIX:
			passdelim (&args,'=');
			arg = nxtarg (&args," \t");
			tl->TLprefix = salloc (arg);
			break;
		case OLIST:
			passdelim (&args,'=');
			arg = nxtarg (&args," \t");
			tl->TLlist = salloc (arg);
			break;
		case OSCAN:
			passdelim (&args,'=');
			arg = nxtarg (&args," \t");
			tl->TLscan = salloc (arg);
			break;
		case OHOST:
			passdelim (&args,'=');
			arg = nxtarg (&args," \t");
			tl->TLhost = salloc (arg);
			break;
		}
	}
	return (nextrel);
}

getrelease (release)
char *release;
{
	TREELIST *tl;
	char buf[STRINGLENGTH];
	char *p,*q;
	int rewound;
	FILE *f;

	if (release == NULL)
		release = salloc (DEFRELEASE);
	listTL = NULL;

	(void) sprintf (buf,FILERELEASES,collname);
	f = fopen (buf,"r");
	if (f != NULL) {
		rewound = TRUE;
		for (;;) {
			p = fgets (buf,sizeof(buf),f);
			if (p == NULL) {
				if (rewound)
					break;
				rewind (f);
				rewound = TRUE;
				continue;
			}
			q = index (p,'\n');
			if (q)  *q = 0;
			if (index ("#;:",*p))  continue;
			q = nxtarg (&p," \t");
			if (strcmp (q,release) != 0)
				continue;
			release = parserelease (&tl,release,p);
			if (tl->TLprefix == NULL)
				tl->TLprefix = prefix;
			else if (chdir (tl->TLprefix) < 0)
				return (FALSE);
			else
				(void) chdir (basedir);
			tl->TLnext = listTL;
			listTL = tl;
			if (release == NULL)
				break;
			rewound = FALSE;
		}
		(void) fclose (f);
	}
	if (release == NULL)
		return (TRUE);
	if (strcmp (release,DEFRELEASE) != 0)
		return (FALSE);
	(void) parserelease (&tl,release,"");
	tl->TLprefix = prefix;
	tl->TLnext = listTL;
	listTL = tl;
	return (TRUE);
}

makescanlists ()
{
	TREELIST *tl;
	char buf[STRINGLENGTH];
	char *p,*q;
	FILE *f;
	char *saveprefix = prefix;
	int count = 0;

	(void) sprintf (buf,FILERELEASES,collname);
	f = fopen (buf,"r");
	if (f != NULL) {
		while (p = fgets (buf,sizeof(buf),f)) {
			q = index (p,'\n');
			if (q)  *q = 0;
			if (index ("#;:",*p))  continue;
			q = nxtarg (&p," \t");
			(void) parserelease (&tl,q,p);
			if ((prefix = tl->TLprefix) == NULL)
				prefix = saveprefix;
			if (prefix != NULL) {
				if (chdir (prefix) < 0)
					goaway ("Can't chdir to %s",prefix);
				(void) chdir (basedir);
			}
			makescan (tl->TLlist,tl->TLscan);
			free ((char *)tl);
			count++;
		}
		(void) fclose (f);
	}
	if (count == 0)
		makescan ((char *)NULL,(char *)NULL);
}

static
scanone (t)
register TREE *t;
{
	register TREE *newt;

	if (newonly && (t->Tflags&FNEW) == 0)
		return (SCMOK);
	newt = Tinsert (&listT,t->Tname,FALSE);
	if (newt == NULL)
		return (SCMOK);
	newt->Tmode = t->Tmode;
	newt->Tflags = t->Tflags;
	newt->Tmtime = t->Tmtime;
	return (SCMOK);
}

getscanlists ()
{
	TREELIST *tl,*stl;

	stl = listTL;
	listTL = NULL;
	while ((tl = stl) != NULL) {
		prefix = tl->TLprefix;
		getscan (tl->TLlist,tl->TLscan);
		tl->TLtree = listT;
		stl = tl->TLnext;
		tl->TLnext = listTL;
		listTL = tl;
	}
	listT = NULL;
	for (tl = listTL; tl != NULL; tl = tl->TLnext)
		(void) Tprocess (tl->TLtree,scanone);
}

static
makescan (listfile,scanfile)
char *listfile,*scanfile;
{
	listT = NULL;
	chkscanfile (scanfile);		/* can we can write a scan file? */
	doscan (listfile);		/* read list file and scan disk */
	makescanfile (scanfile);	/* record names in scan file */
	Tfree (&listT);			/* free file list tree */
}

static
getscan (listfile,scanfile)
char *listfile,*scanfile;
{
        struct tm *utc_time;
        
	listT = NULL;
	if (!getscanfile(scanfile)) {	/* check for pre-scanned file list */
		scantime = time ((long *)NULL);
		doscan (listfile);	/* read list file and scan disk */
	}
}

static
doscan (listfile)
	char *listfile;
{
	char buf[STRINGLENGTH];
	int listone ();

	upgT = NULL;
	flagsT = NULL;
	omitT = NULL;
	omanyT = NULL;
	execT = NULL;
	symT = NULL;
	rsymT = NULL;
	if (listfile == NULL)
		listfile = FILELISTDEF;
	(void) sprintf (buf,FILELIST,collname,listfile);
	readlistfile (buf);		/* get contents of list file */
	(void) Tprocess (upgT,listone); /* build list of files specified */
	cdprefix ((char *)NULL);
	Tfree (&upgT);
	Tfree (&flagsT);
	Tfree (&omitT);
	Tfree (&omanyT);
	Tfree (&execT);
	Tfree (&symT);
	Tfree (&rsymT);
}

static
readlistfile (fname)
char *fname;
{
	char buf[STRINGLENGTH+MAXPATHLEN*4+1],*p;
	register char *q,*r;
	register FILE *f;
	register int ltn,n,i,flags;
	register TREE **t;
	register LISTTYPE lt;
	char *speclist[SPECNUMBER];

	f = fopen (fname,"r");
	if (f == NULL)  goaway ("Can't read list file %s",fname);
	cdprefix (prefix);
	while (p = fgets (buf,sizeof(buf),f)) {
		if (q = index (p,'\n'))  *q = '\0';
		if (index ("#;:",*p))  continue;
		q = nxtarg (&p," \t");
		if (*q == '\0') continue;
		for (ltn = 0; ltname[ltn] && strcmp(q,ltname[ltn]) != 0; ltn++);
		if (ltname[ltn] == NULL)
			goaway ("Invalid list file keyword %s",q);
		lt = (LISTTYPE) ltn;
		flags = 0;
		switch (lt) {
		case LUPGRADE:
			t = &upgT;
			break;
		case LBACKUP:
			t = &flagsT;
			flags = FBACKUP;
			break;
		case LNOACCT:
			t = &flagsT;
			flags = FNOACCT;
			break;
		case LSYMLINK:
			t = &symT;
			break;
		case LRSYMLINK:
			t = &rsymT;
			break;
		case LOMIT:
			t = &omitT;
			break;
		case LOMITANY:
			t = &omanyT;
			break;
		case LALWAYS:
			t = &upgT;
			flags = FALWAYS;
			break;
		case LINCLUDE:
			while (*(q=nxtarg(&p," \t"))) {
				cdprefix ((char *)NULL);
				n = expand (q,speclist,SPECNUMBER);
				for (i = 0; i < n && i < SPECNUMBER; i++) {
					readlistfile (speclist[i]);
					cdprefix ((char *)NULL);
					free (speclist[i]);
				}
				cdprefix (prefix);
			}
			continue;
		case LEXECUTE:
			r = p = q = skipover (p," \t");
			do {
				q = p = skipto (p," \t(");
				p = skipover (p," \t");
			} while (*p != '(' && *p != '\0');
			if (*p++ == '(') {
				*q = '\0';
				do {
					q = nxtarg (&p," \t)");
					if (*q == 0)
						_argbreak = ')';
					else
						expTinsert (q,&execT,0,r);
				} while (_argbreak != ')');
				continue;
			}
			/* fall through */
		default:
			goaway ("Error in handling list file keyword %d",ltn);
		}
		while (*(q=nxtarg(&p," \t"))) {
			if (lt == LOMITANY)
				(void) Tinsert (t,q,FALSE);
			else
				expTinsert (q,t,flags,(char *)NULL);
		}
	}
	(void) fclose (f);
}

static
expTinsert (p,t,flags,exec)
char *p;
TREE **t;
int flags;
char *exec;
{
	register int n, i;
	register TREE *newt;
	char *speclist[SPECNUMBER];
	char buf[STRINGLENGTH];

	n = expand (p,speclist,SPECNUMBER);
	for (i = 0; i < n && i < SPECNUMBER; i++) {
		newt = Tinsert (t,speclist[i],TRUE);
		newt->Tflags |= flags;
		if (exec) {
			(void) sprintf (buf,exec,speclist[i]);
			(void) Tinsert (&newt->Texec,buf,FALSE);
		}
		free (speclist[i]);
	}
}

static
listone (t)		/* expand and add one name from upgrade list */
TREE *t;
{
	listentry(t->Tname,t->Tname,(char *)NULL,(t->Tflags&FALWAYS) != 0);
	return (SCMOK);
}

static
listentry(name,fullname,updir,always)
register char *name, *fullname, *updir;
int always;
{
	struct stat statbuf;
	int link = 0;
	int omitanyone ();

	if (Tlookup (refuseT,fullname))  return;
	if (!always) {
		if (Tsearch (omitT,fullname))  return;
		if (Tprocess (omanyT,omitanyone,fullname) != SCMOK)
			return;
	}
	if (lstat(name,&statbuf) < 0)
		return;
	if ((statbuf.st_mode&S_IFMT) == S_IFLNK) {
		if (Tsearch (symT,fullname)) {
			listname (fullname,&statbuf);
			return;
		}
		if (Tlookup (rsymT,fullname)) {
			listname (fullname,&statbuf);
			return;
		}
		if (updir) link++;
		if (stat(name,&statbuf) < 0) return;
	}
	if ((statbuf.st_mode&S_IFMT) == S_IFDIR) {
		if (access(name,R_OK|X_OK) < 0) return;
		if (chdir(name) < 0) return;
		listname (fullname,&statbuf);
		if (trace) {
			printf ("Scanning directory %s\n",fullname);
			(void) fflush (stdout);
		}
		listdir (fullname,always);
		if (updir == 0 || link) {
			(void) chdir (basedir);
			if (prefix) (void) chdir (prefix);
			if (updir && *updir) (void) chdir (updir);
		} else
			(void) chdir ("..");
		return;
	}
	if (access(name,R_OK) < 0) return;
#ifdef RCSSTAT
        if (candorcs) {
                char rcs_release[STRINGLENGTH];
                int status;
                if (rcs_branch != NULL)
#ifdef CVS
                        sprintf(rcs_release, "-r %s", rcs_branch);
#else
                        sprintf(rcs_release, "-r%s", rcs_branch);
#endif
                else
                        rcs_release[0] = '\0';
#ifdef CVS
                sprintf(sys_com, "cvs -d %s -r -l -Q co -p %s %s > %s\n", cvs_root, rcs_release, name, rcs_file);
#else
                status = runp("rcsstat", "rcsstat", "-q", rcs_release, name, 0);
#endif
                if (status != 0) return;
        }
#endif
	listname (fullname,&statbuf);
}

static
listname (name,st)
register char *name;
register struct stat *st;
{
	register TREE *t,*ts;
	register int new;
	register TREELIST *tl;

	new = st->st_ctime > lasttime;
	if (newonly && !new) {
		for (tl = listTL; tl != NULL; tl = tl->TLnext)
			if (ts = Tsearch (tl->TLtree,name))
				ts->Tflags &= ~FNEW;
		return;
	}
	t = Tinsert (&listT,name,FALSE);
	if (t == NULL)  return;
	t->Tmode = st->st_mode;
	t->Tctime = st->st_ctime;
	t->Tmtime = st->st_mtime;
	if (new)  t->Tflags |= FNEW;
	if (ts = Tsearch (flagsT,name))
		t->Tflags |= ts->Tflags;
	if (ts = Tsearch (execT,name)) {
		t->Texec = ts->Texec;
		ts->Texec = NULL;
	}
}

static
listdir (name,always)		/* expand directory */
char *name;
int always;
{
#ifdef HAS_POSIX_DIR
	struct dirent *dentry;
#else
	struct direct *dentry;
#endif
	register DIR *dirp;
	char ename[STRINGLENGTH],newname[STRINGLENGTH],filename[STRINGLENGTH];
	register char *p,*newp;
	register int i;

	dirp = opendir (".");
	if (dirp == 0) return;	/* unreadable: probably protected */

	p = name;		/* punt leading ./ and trailing / */
	newp = newname;
	if (p[0] == '.' && p[1] == '/') {
		p += 2;
		while (*p == '/') p++;
	}
	while (*newp++ = *p++) ;	/* copy string */
	--newp;				/* trailing null */
	while (newp > newname && newp[-1] == '/') --newp; /* trailing / */
	*newp = 0;
	if (strcmp (newname,".") == 0) newname[0] = 0;	/* "." ==> "" */

	while (dentry=readdir(dirp)) {
		if (dentry->d_ino == 0) continue;
		if (strcmp(dentry->d_name,".") == 0) continue;
		if (strcmp(dentry->d_name,"..") == 0) continue;
		for (i=0; i<=MAXNAMLEN && dentry->d_name[i]; i++)
			ename[i] = dentry->d_name[i];
		ename[i] = 0;
		if (*newname)
			(void) sprintf (filename,"%s/%s",newname,ename);
		else
			(void) strcpy (filename,ename);
		listentry(ename,filename,newname,always);
	}
	closedir (dirp);
}

static
omitanyone (t,filename)
TREE *t;
char **filename;
{
	if (anyglob (t->Tname,*filename))
		return (SCMERR);
	return (SCMOK);
}

static
anyglob (pattern,match)
char *pattern,*match;
{
	register char *p,*m;
	register char *pb,*pe;

	p = pattern; 
	m = match;
	while (*m && *p == *m ) { 
		p++; 
		m++; 
	}
	if (*p == '\0' && *m == '\0')
		return (TRUE);
	switch (*p++) {
	case '*':
		for (;;) {
			if (*p == '\0')
				return (TRUE);
			if (*m == '\0')
				return (*p == '\0');
			if (anyglob (p,++m))
				return (TRUE);
		}
	case '?':
		return (anyglob (p,++m));
	case '[':
		pb = p;
		while (*(++p) != ']')
			if (*p == '\0')
				return (FALSE);
		pe = p;
		for (p = pb + 1; p != pe; p++) {
			switch (*p) {
			case '-':
				if (p == pb && *m == '-') {
					p = pe + 1;
					return (anyglob (p,++m));
				}
				if (p == pb)
					continue;
				if ((p + 1) == pe)
					return (FALSE);
				if (*m > *(p - 1) &&
				    *m <= *(p + 1)) {
					p = pe + 1;
					return (anyglob (p,++m));
				}
				continue;
			default:
				if (*m == *p) {
					p = pe + 1;
					return (anyglob (p,++m));
				}
			}
		}
		return (FALSE);
	default:
		return (FALSE);
	}
}

/*****************************************
 ***    R E A D   S C A N   F I L E    ***
 *****************************************/

static
int getscanfile (scanfile)
char *scanfile;
{
	char buf[STRINGLENGTH];
	char fname[MAXPATHLEN];
	struct stat sbuf;
	register FILE *f;
	TREE ts;
	register char *p,*q;
	register TREE *tmp, *t = NULL;
	register notwanted;
	register TREELIST *tl;
        
	if (scanfile == NULL)
		scanfile = FILESCANDEF;
	(void) sprintf (buf,FILESCAN,collname,scanfile);
	if (stat(buf,&sbuf) < 0)
		return (FALSE);
	if ((f = fopen (buf,"r")) == NULL)
		return (FALSE);
	if ((p = fgets (buf,sizeof(buf),f)) == NULL) {
		(void) fclose (f);
		return (FALSE);
	}
	if (q = index (p,'\n'))  *q = '\0';
	if (*p++ != 'V') {
		(void) fclose (f);
		return (FALSE);
	}
	if (atoi (p) != SCANVERSION) {
		(void) fclose (f);
		return (FALSE);
	}
	scantime = sbuf.st_mtime;	/* upgrade time is time of supscan,
					 * i.e. time of creation of scanfile */
	if (newonly && scantime == lasttime) {
		(void) fclose (f);
		return (TRUE);
	}
	notwanted = FALSE;
	while (p = fgets (buf,sizeof(buf),f)) {
		q = index (p,'\n');
		if (q)  *q = 0;
		ts.Tflags = 0;
		if (*p == 'X') {
			if (notwanted)  continue;
			if (t == NULL)
				goaway ("scanfile format inconsistant");
			(void) Tinsert (&t->Texec,++p,FALSE);
			continue;
		}
		notwanted = FALSE;
		if (*p == 'B') {
			p++;
			ts.Tflags |= FBACKUP;
		}
		if (*p == 'N') {
			p++;
			ts.Tflags |= FNOACCT;
		}
		if ((q = index (p,' ')) == NULL)
			goaway ("scanfile format inconsistant");
		*q++ = '\0';
		ts.Tmode = atoo (p);
		p = q;
		if ((q = index (p,' ')) == NULL)
			goaway ("scanfile format inconsistant");
		*q++ = '\0';
		ts.Tctime = atoi (p);
		p = q;
		if ((q = index (p,' ')) == NULL)
			goaway ("scanfile format inconsistant");
		*q++ = 0;
		ts.Tmtime = atoi (p);
		(void) strunvis(fname, q);
		if (ts.Tctime > lasttime)
			ts.Tflags |= FNEW;
		else if (newonly) {
			for (tl = listTL; tl != NULL; tl = tl->TLnext)
				if (tmp = Tsearch (tl->TLtree,fname))
					tmp->Tflags &= ~FNEW;
			notwanted = TRUE;
			continue;
		}
		if (Tlookup (refuseT,fname)) {
			notwanted = TRUE;
			continue;
		}
		t = Tinsert (&listT,fname,TRUE);
		t->Tmode = ts.Tmode;
		t->Tflags = ts.Tflags;
		t->Tctime = ts.Tctime;
		t->Tmtime = ts.Tmtime;
	}
	(void) fclose (f);
	return (TRUE);
}

/*******************************************
 ***    W R I T E   S C A N   F I L E    ***
 *******************************************/

static chkscanfile (scanfile)
char *scanfile;
{
	char tname[STRINGLENGTH], fname[STRINGLENGTH];
	FILE *f;

	if (scanfile == NULL)
		scanfile = FILESCANDEF;
	(void) sprintf (fname,FILESCAN,collname,scanfile);
	(void) sprintf (tname,"%s.temp",fname);
	if (NULL == (f = fopen (tname, "w")))
		goaway ("Can't test scan file temp %s for %s",tname,collname);
	else {
		(void) unlink (tname);
		(void) fclose (f);
	}
}

static makescanfile (scanfile)
char *scanfile;
{
	char tname[STRINGLENGTH],fname[STRINGLENGTH];
	struct timeval tbuf[2];
	FILE *scanF;			/* output file for scanned file list */
	int recordone ();

	if (scanfile == NULL)
		scanfile = FILESCANDEF;
	(void) sprintf (fname,FILESCAN,collname,scanfile);
	(void) sprintf (tname,"%s.temp",fname);
	scanF = fopen (tname,"w");
	if (scanF == NULL)
		goaway ("Can't write scan file temp %s for %s",tname,collname);
	fprintf (scanF,"V%d\n",SCANVERSION);
	(void) Tprocess (listT,recordone,scanF);
	(void) fclose (scanF);
	if (rename (tname,fname) < 0)
		goaway ("Can't change %s to %s",tname,fname);
	(void) unlink (tname);
	tbuf[0].tv_sec = time((long *)NULL);  tbuf[0].tv_usec = 0;
	tbuf[1].tv_sec = scantime;  tbuf[1].tv_usec = 0;
	(void) utimes (fname,tbuf);
}

static
recordone (t,scanF)
TREE *t;
FILE **scanF;
{
	int recordexec ();
	char fname[MAXPATHLEN*4+1];

	if (t->Tflags&FBACKUP)  fprintf (*scanF,"B");
	if (t->Tflags&FNOACCT)  fprintf (*scanF,"N");
	strvis(fname, t->Tname, VIS_WHITE);
	fprintf (*scanF,"%o %d %d %s\n",
		t->Tmode,t->Tctime,t->Tmtime,fname);
	(void) Tprocess (t->Texec,recordexec,*scanF);
	return (SCMOK);
}

static
recordexec (t,scanF)
TREE *t;
FILE **scanF;
{
	char fname[MAXPATHLEN*4+1];
	strvis(fname, t->Tname, VIS_WHITE);
	fprintf(*scanF,"X%s\n",fname);
	return (SCMOK);
}

cdprefix (prefix)
char *prefix;
{
	static char *curprefix = NULL;

	if (curprefix == NULL) {
		if (prefix == NULL)
			return;
		(void) chdir (prefix);
		curprefix = prefix;
		return;
	}
	if (prefix == NULL) {
		(void) chdir (basedir);
		curprefix = NULL;
		return;
	}
	if (prefix == curprefix)
		return;
	if (strcmp (prefix, curprefix) == 0) {
		curprefix = prefix;
		return;
	}
	(void) chdir (basedir);
	(void) chdir (prefix);
	curprefix = prefix;
}