From 7619ff47588e33444979a68d65edc1cd2472ddea Mon Sep 17 00:00:00 2001
From: Edward Wang <edward@ucbvax.Berkeley.EDU>
Date: Sun, 7 May 1989 08:02:58 -0800
Subject: [PATCH] show last login time if more recent than current logins,
 cleaned up, speeded up, put people in hash table, separate login info from
 personal info

SCCS-vsn: usr.bin/finger/finger.c 5.14
SCCS-vsn: usr.bin/finger/finger.h 5.2
SCCS-vsn: usr.bin/finger/lprint.c 5.2
SCCS-vsn: usr.bin/finger/sprint.c 5.2
SCCS-vsn: usr.bin/finger/util.c 5.2
---
 usr/src/usr.bin/finger/finger.c | 150 ++++++++++------------------
 usr/src/usr.bin/finger/finger.h |  38 +++++--
 usr/src/usr.bin/finger/lprint.c |  88 +++++++---------
 usr/src/usr.bin/finger/sprint.c |  85 ++++++++--------
 usr/src/usr.bin/finger/util.c   | 172 +++++++++++++++++++++++++++-----
 5 files changed, 306 insertions(+), 227 deletions(-)

diff --git a/usr/src/usr.bin/finger/finger.c b/usr/src/usr.bin/finger/finger.c
index 43bc5b6e94..873190b504 100644
--- a/usr/src/usr.bin/finger/finger.c
+++ b/usr/src/usr.bin/finger/finger.c
@@ -25,7 +25,7 @@ char copyright[] =
 #endif /* not lint */
 
 #ifndef lint
-static char sccsid[] = "@(#)finger.c	5.13 (Berkeley) %G%";
+static char sccsid[] = "@(#)finger.c	5.14 (Berkeley) %G%";
 #endif /* not lint */
 
 /*
@@ -47,10 +47,8 @@ static char sccsid[] = "@(#)finger.c	5.13 (Berkeley) %G%";
 #include "finger.h"
 #include "pathnames.h"
 
-struct utmp user;
-PERSON *head;
 time_t now;
-int entries, lflag, sflag, mflag, pplan;
+int lflag, sflag, mflag, pplan;
 char tbuf[1024];
 
 main(argc, argv)
@@ -95,7 +93,7 @@ main(argc, argv)
 		if (!lflag)
 			sflag = 1;	/* if -l not explicit, force -s */
 		loginlist();
-		if (!head)
+		if (entries == 0)
 			(void)printf("No one logged on.\n");
 	} else {
 		userlist(argv);
@@ -107,7 +105,7 @@ main(argc, argv)
 		if (!sflag)
 			lflag = 1;	/* if -s not explicit, force -l */
 	}
-	if (head) {
+	if (entries != 0) {
 		if (lflag)
 			lflag_print();
 		else
@@ -121,66 +119,52 @@ loginlist()
 	register PERSON *pn;
 	register int fd;
 	struct passwd *pw;
-	char name[UT_NAMESIZE + 1], *strdup(), *malloc();
+	struct utmp user;
+	char name[UT_NAMESIZE + 1];
 
 	if ((fd = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
 		(void)fprintf(stderr, "finger: can't read %s.\n", _PATH_UTMP);
 		exit(2);
 	}
 	name[UT_NAMESIZE] = NULL;
-	while(read(fd, (char *)&user, sizeof(user)) == sizeof(user)) {
+	while (read(fd, (char *)&user, sizeof(user)) == sizeof(user)) {
 		if (!user.ut_name[0])
 			continue;
-		bcopy(user.ut_name, name, UT_NAMESIZE);
-		if (!(pw = getpwnam(name)))
-			continue;
-		if (!(pn = (PERSON *)malloc((u_int)sizeof(PERSON)))) {
-			(void)fprintf(stderr, "finger: out of space.\n");
-			exit(1);
+		if ((pn = find_person(user.ut_name)) == NULL) {
+			bcopy(user.ut_name, name, UT_NAMESIZE);
+			if ((pw = getpwnam(name)) == NULL)
+				continue;
+			pn = enter_person(pw);
 		}
-		++entries;
-		pn->next = head;
-		head = pn;
-		utcopy(&user, pn);
-		userinfo(pn, pw);
-		find_idle_and_ttywrite(pn);
-		pn->info = LOGGEDIN;
+		enter_where(&user, pn);
 	}
 	(void)close(fd);
+	for (pn = phead; lflag && pn != NULL; pn = pn->next)
+		enter_lastlog(pn);
 }
 
 #define	ARGIGNORE	(char *)0x01
 userlist(argv)
 	char **argv;
 {
-	register PERSON *nethead, *p, *pn;
-	register struct passwd *pw;
-	register char **a1, **a2;
-	int fd, dolocal, nelem;
-	char **sargv, **arglist, *malloc(), *rindex(), *strcpy();
-
-	/* suppress duplicates while it's still easy */
-	for (a1 = argv; *a1; ++a1)
-		for (a2 = a1 + 1; *a2; ++a2)
-			if (!strcasecmp(*a1, *a2)) {
-				*a1 = ARGIGNORE;
-				break;
-			}
+	register char **ap;
+	register PERSON *pn;
+	PERSON *nethead;
+	struct utmp user;
+	struct passwd *pw;
+	int fd, dolocal, *index();
 
 	/* pull out all network requests */
-	for (sargv = argv, dolocal = 0, nethead = NULL; *argv; ++argv) {
-		if (!index(*argv, '@')) {
+	for (ap = argv, dolocal = 0, nethead = NULL; *ap != NULL; ap++) {
+		if (!index(*ap, '@')) {
 			dolocal = 1;
 			continue;
 		}
-		if (!(pn = (PERSON *)malloc((u_int)sizeof(PERSON)))) {
-			(void)fprintf(stderr, "finger: out of space.\n");
-			exit(1);
-		}
+		pn = palloc();
 		pn->next = nethead;
 		nethead = pn;
-		pn->name = *argv;
-		*argv = ARGIGNORE;
+		pn->name = *ap;
+		*ap = ARGIGNORE;
 	}
 
 	if (!dolocal)
@@ -188,44 +172,33 @@ userlist(argv)
 
 	/*
 	 * traverse the list of possible login names and check the login name
-	 * and real name against the name specified by the user.  Possible
-	 * speedup would be to use getpwnam(3) if mflag set -- maybe not
-	 * worthwhile, given that the default is the mflag off.
+	 * and real name against the name specified by the user.
 	 */
-	nelem = argv - sargv + 1;
-	if (!(arglist =
-	    (char **)malloc((u_int)(nelem * sizeof(char *))))) {
-		(void)fprintf(stderr, "finger: out of space.\n");
-		exit(1);
-	}
-	bcopy((char *)sargv, (char *)arglist, nelem * sizeof(char *));
-	while (pw = getpwent()) {
-		for (argv = sargv; *argv; ++argv) {
-			if (*argv == ARGIGNORE)
+	if (mflag)
+		for (ap = argv; *ap != NULL; ap++) {
+			if (*ap == ARGIGNORE)
+				continue;
+			if ((pw = getpwnam(*ap)) == NULL)
+				continue;
+			enter_person(pw);
+			*ap = ARGIGNORE;
+		}
+	else while (pw = getpwent())
+		for (ap = argv; *ap != NULL; ap++) {
+			if (*ap == ARGIGNORE)
 				continue;
-			if (strcasecmp(pw->pw_name, *argv) &&
-			    (mflag || !match(pw, *argv)))
+			if (strcasecmp(pw->pw_name, *ap) && !match(pw, *ap))
 				continue;
-			if (!(pn = (PERSON *)malloc((u_int)sizeof(PERSON)))) {
-				(void)fprintf(stderr,
-				    "finger: out of space.\n");
-				exit(1);
-			}
-			++entries;
-			pn->next = head;
-			head = pn;
-			userinfo(pn, pw);
-			pn->info = FOUND;
-			arglist[argv - sargv] = ARGIGNORE;
+			enter_person(pw);
+			*ap = ARGIGNORE;
 			/* don't break, may be listed multiple times */
 		}
-	}
 
 	/* list errors */
-	for (; *arglist; ++arglist)
-		if (*arglist != ARGIGNORE)
+	for (ap = argv; *ap != NULL; ap++)
+		if (*ap != ARGIGNORE)
 			(void)fprintf(stderr,
-			    "finger: %s: no such user.\n", *arglist);
+			    "finger: %s: no such user.\n", *ap);
 
 	/* handle network requests */
 net:	for (pn = nethead; pn; pn = pn->next) {
@@ -234,7 +207,7 @@ net:	for (pn = nethead; pn; pn = pn->next) {
 			putchar('\n');
 	}
 
-	if (!head)
+	if (entries == 0)
 		return;
 
 	/*
@@ -248,32 +221,11 @@ net:	for (pn = nethead; pn; pn = pn->next) {
 	while (read(fd, (char *)&user, sizeof(user)) == sizeof(user)) {
 		if (!user.ut_name[0])
 			continue;
-		for (pn = head; pn; pn = pn->next) {
-			if (strncasecmp(pn->name, user.ut_name, UT_NAMESIZE))
-				continue;
-			if (pn->info == LOGGEDIN) {
-				if (!(p =
-				    (PERSON *)malloc((u_int)sizeof(PERSON)))) {
-					(void)fprintf(stderr,
-					    "finger: out of space.\n");
-					exit(1);
-				}
-				++entries;
-				p->name = pn->name;
-				(void)strcpy(p->tty, pn->tty);
-				/* link in so finds `real' entry first! */
-				p->next = pn->next;
-				pn->next = p;
-				pn = p;
-			}
-			pn->info = LOGGEDIN;
-			utcopy(&user, pn);
-			find_idle_and_ttywrite(pn);
-			/* don't break, may be listed multiple times... */
-		}
+		if ((pn = find_person(user.ut_name)) == NULL)
+			continue;
+		enter_where(&user, pn);
 	}
 	(void)close(fd);
-	for (pn = head; pn; pn = pn->next)
-		if (pn->info == FOUND)
-			find_when(pn);
+	for (pn = phead; pn != NULL; pn = pn->next)
+		enter_lastlog(pn);
 }
diff --git a/usr/src/usr.bin/finger/finger.h b/usr/src/usr.bin/finger/finger.h
index c324de95b7..3b199a5277 100644
--- a/usr/src/usr.bin/finger/finger.h
+++ b/usr/src/usr.bin/finger/finger.h
@@ -17,20 +17,21 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- *	@(#)finger.h	5.1 (Berkeley) %G%
+ *	@(#)finger.h	5.2 (Berkeley) %G%
  */
 
 #include <pwd.h>
 #include <utmp.h>
 
-enum status { PRINTED, FOUND, LOGGEDIN };
+/*
+ * All unique persons are linked in a list headed by "head" and linkd
+ * by the "next" field, as well as kept in a hash table.
+ */
+
 typedef struct person {
 	struct person *next;		/* link to next person */
-	time_t loginat;			/* time of (last) login */
-	time_t idletime;		/* how long idle (if logged in) */
+	struct person *hlink;		/* link to next person in hash bucket */
 	uid_t uid;			/* user id */
-	enum status info;		/* type/status of request */
-	short writable;			/* tty is writable */
 	char *dir;			/* user's home directory */
 	char *homephone;		/* pointer to home phone no. */
 	char *name;			/* login name */
@@ -38,8 +39,31 @@ typedef struct person {
 	char *officephone;		/* pointer to office phone no. */
 	char *realname;			/* pointer to full name */
 	char *shell;			/* user's shell */
+	struct where *whead, *wtail;	/* list of where he is or has been */
+} PERSON;
+
+enum status { LASTLOG, LOGGEDIN };
+
+typedef struct where {
+	struct where *next;		/* next place he is or has been */
+	enum status info;		/* type/status of request */
+	short writable;			/* tty is writable */
+	time_t loginat;			/* time of (last) login */
+	time_t idletime;		/* how long idle (if logged in) */
 	char tty[UT_LINESIZE+1];	/* null terminated tty line */
 	char host[UT_HOSTSIZE+1];	/* null terminated remote host name */
-} PERSON;
+} WHERE;
+
+#define	HBITS	8			/* number of bits in hash code */
+#define	HSIZE	(1 << 8)		/* hash table size */
+#define	HMASK	(HSIZE - 1)		/* hash code mask */
+
+PERSON *htab[HSIZE];			/* the buckets */
+PERSON *phead, *ptail;			/* the linked list of all people */
+
+int entries;				/* number of people */
+
+PERSON *enter_person(), *find_person(), *palloc();
+WHERE *walloc();
 
 extern char tbuf[1024];			/* temp buffer for anybody */
diff --git a/usr/src/usr.bin/finger/lprint.c b/usr/src/usr.bin/finger/lprint.c
index d40c93caa6..284aaed6d8 100644
--- a/usr/src/usr.bin/finger/lprint.c
+++ b/usr/src/usr.bin/finger/lprint.c
@@ -19,7 +19,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)lprint.c	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)lprint.c	5.2 (Berkeley) %G%";
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -38,20 +38,13 @@ static char sccsid[] = "@(#)lprint.c	5.1 (Berkeley) %G%";
 
 lflag_print()
 {
-	extern PERSON *head;
 	extern int pplan;
 	register PERSON *pn;
 
-	for (pn = head;;) {
-		if (pn->info == PRINTED) {
-			if (!(pn = pn->next))
-				break;
-			continue;
-		}
+	for (pn = phead;;) {
 		lprint(pn);
 		if (!pplan) {
-			(void)show_text(pn->dir, _PATH_PROJECT,
-			    "Project:");
+			(void)show_text(pn->dir, _PATH_PROJECT, "Project:");
 			if (!show_text(pn->dir, _PATH_PLAN, "Plan:"))
 				(void)printf("No Plan.\n");
 		}
@@ -66,7 +59,7 @@ lprint(pn)
 {
 	extern time_t now;
 	register struct tm *delta;
-	register PERSON *p;
+	register WHERE *w;
 	register int cpr, len, maxlen;
 	int oddfield;
 	time_t time();
@@ -116,34 +109,33 @@ lprint(pn)
 		putchar('\n');
 
 	/*
-	 * long format con't: if logged in
+	 * long format con't: * if logged in
 	 *	terminal
 	 *	idle time
 	 *	if messages allowed
 	 *	where logged in from
+	 * if not logged in
+	 *	when last logged in
 	 */
-	if (pn->info == LOGGEDIN) {
-		/* find out longest device name for this user for formatting */
-		for (maxlen = -1, p = pn; p; p = p->next)
-			if (!strcmp(p->name, pn->name) &&
-			    (len = strlen(p->tty)) > maxlen)
-				maxlen = len;
-		/* find rest of entries for user */
-		for (p = pn; p; p = p->next) {
-			if (strcmp(p->name, pn->name))
-				continue;
-			p->info = PRINTED;
+	/* find out longest device name for this user for formatting */
+	for (w = pn->whead; w != NULL; w = w->next)
+		if ((len = strlen(w->tty)) > maxlen)
+			maxlen = len;
+	/* find rest of entries for user */
+	for (w = pn->whead; w != NULL; w = w->next) {
+		switch (w->info) {
+		case LOGGEDIN:
 			cpr = printf("On since %16.16s on %s",
-			    ctime(&p->loginat), p->tty);
+			    ctime(&w->loginat), w->tty);
 			/*
 			 * idle time is tough; if have one, print a comma,
 			 * then spaces to pad out the device name, then the
 			 * idle time.  Follow with a comma if a remote login.
 			 */
-			delta = gmtime(&p->idletime);
+			delta = gmtime(&w->idletime);
 			if (delta->tm_yday || delta->tm_hour || delta->tm_min) {
 				cpr += printf("%-*s idle ",
-				    maxlen - strlen(p->tty) + 1, ",");
+				    maxlen - strlen(w->tty) + 1, ",");
 				if (delta->tm_yday > 0) {
 					cpr += printf("%d day%s ",
 					   delta->tm_yday,
@@ -151,40 +143,32 @@ lprint(pn)
 				}
 				cpr += printf("%d:%02d",
 				    delta->tm_hour, delta->tm_min);
-				if (*p->host) {
+				if (*w->host) {
 					putchar(',');
 					++cpr;
 				}
 			}
-			if (!p->writable)
+			if (!w->writable)
 				cpr += printf(" (messages off)");
-			if (*p->host) {
-				if (LINE_LEN < (cpr + 6 +
-				    strlen(p->host))) {
-					(void)printf("\n   ");
-				}
-				(void)printf(" from %s", p->host);
+			break;
+		case LASTLOG:
+			if (w->loginat == 0) {
+				(void)printf("Never logged in.");
+				break;
 			}
-			(void)putchar('\n');
+			t = ctime(&w->loginat);
+			if (now - w->loginat > SECSPERDAY * DAYSPERNYEAR / 2)
+				cpr = printf("Last login %10.10s, %4.4s on %s",
+				    t, t + 20, w->tty);
+			else
+				cpr = printf("Last login %16.16s on %s",
+					t, w->tty);
+			break;
 		}
-	}
-	/*
-	 * long format con't: if not logged in
-	 *	when last logged in
-	 */
-	else if (!pn->loginat)
-		(void)printf("Never logged in.\n");
-	else {
-		t = ctime(&pn->loginat);
-		if (now - pn->loginat > SECSPERDAY * DAYSPERNYEAR / 2)
-			cpr = printf("Last login %10.10s, %4.4s on %s",
-			    t, t + 20, pn->tty);
-		else
-			cpr = printf("Last login %16.16s on %s", t, pn->tty);
-		if (*pn->host) {
-			if (LINE_LEN < (cpr + 6 + strlen(pn->host)))
+		if (*w->host) {
+			if (LINE_LEN < (cpr + 6 + strlen(w->host)))
 				(void)printf("\n   ");
-			(void)printf(" from %s", pn->host);
+			(void)printf(" from %s", w->host);
 		}
 		putchar('\n');
 	}
diff --git a/usr/src/usr.bin/finger/sprint.c b/usr/src/usr.bin/finger/sprint.c
index 194b13e7a7..3c5b765abb 100644
--- a/usr/src/usr.bin/finger/sprint.c
+++ b/usr/src/usr.bin/finger/sprint.c
@@ -19,7 +19,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)sprint.c	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)sprint.c	5.2 (Berkeley) %G%";
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -34,6 +34,7 @@ sflag_print()
 {
 	extern time_t now;
 	register PERSON *pn;
+	register WHERE *w;
 	register int cnt;
 	register char *p;
 	PERSON **list, **sort();
@@ -56,47 +57,51 @@ sflag_print()
 	 */
 #define	MAXREALNAME	20
 	(void)printf("%-*s %-*s %s\n", UT_NAMESIZE, "Login", MAXREALNAME,
-	    "Name", "Tty  Idle Login        Office      Office Phone");
+	    "Name", "Tty  Idle  Login        Office      Office Phone");
 	for (cnt = 0; cnt < entries; ++cnt) {
 		pn = list[cnt];
-		 (void)printf("%-*.*s %-*.*s ", UT_NAMESIZE, UT_NAMESIZE,
-		    pn->name, MAXREALNAME, MAXREALNAME,
-		    pn->realname ? pn->realname : "");
-		if (!pn->loginat) {
-			(void)printf("          Never logged in\n");
-			continue;
+		for (w = pn->whead; w != NULL; w = w->next) {
+			(void)printf("%-*.*s %-*.*s ", UT_NAMESIZE, UT_NAMESIZE,
+			    pn->name, MAXREALNAME, MAXREALNAME,
+			    pn->realname ? pn->realname : "");
+			if (!w->loginat) {
+				(void)printf("  *     *  No logins   ");
+				goto office;
+			}
+			(void)putchar(w->info == LOGGEDIN && !w->writable ?
+			    '*' : ' ');
+			if (*w->tty)
+				(void)printf("%-2.2s ",
+				    w->tty[0] != 't' || w->tty[1] != 't' ||
+				    w->tty[2] != 'y' ? w->tty : w->tty + 3);
+			else
+				(void)printf("   ");
+			if (w->info == LOGGEDIN) {
+				stimeprint(w);
+				(void)printf("  ");
+			} else
+				(void)printf("    *  ");
+			p = ctime(&w->loginat);
+			(void)printf("%.6s", p + 4);
+			if (now - w->loginat >= SECSPERDAY * DAYSPERNYEAR / 2)
+				(void)printf("  %.4s", p + 20);
+			else
+				(void)printf(" %.5s", p + 11);
+office:			if (pn->office)
+				(void)printf(" %-11.11s", pn->office);
+			else if (pn->officephone)
+				(void)printf(" %-11.11s", " ");
+			if (pn->officephone)
+				(void)printf(" %s", pn->officephone);
+			putchar('\n');
 		}
-		(void)printf(pn->info == LOGGEDIN &&
-		    !pn->writable ? "*" : " ");
-		if (*pn->tty)
-			(void)printf("%-2.2s ",
-			    pn->tty[0] != 't' || pn->tty[1] != 't' ||
-			    pn->tty[2] != 'y' ? pn->tty : pn->tty + 3);
-		else
-			(void)printf("   ");
-		stimeprint(pn);
-		p = ctime(&pn->loginat);
-		(void)printf(" %.6s", p + 4);
-		if (now - pn->loginat >= SECSPERDAY * DAYSPERNYEAR / 2)
-			(void)printf(" %.4s ", p + 20);
-		else
-			(void)printf(" %.5s", p + 11);
-		if (pn->office)
-			(void)printf(" %-11.11s", pn->office);
-		else if (pn->officephone)
-			(void)printf(" %-11.11s", " ");
-		if (pn->officephone)
-			(void)printf(" %s", pn->officephone);
-		putchar('\n');
 	}
 }
 
 PERSON **
 sort()
 {
-	extern PERSON *head;
-	register PERSON *pn;
-	register int cnt;
+	register PERSON *pn, **lp;
 	PERSON **list;
 	int psort();
 	char *malloc();
@@ -105,8 +110,8 @@ sort()
 		(void)fprintf(stderr, "finger: out of space.\n");
 		exit(1);
 	}
-	for (pn = head, cnt = 0; cnt < entries; pn = pn->next)
-		list[cnt++] = pn;
+	for (lp = list, pn = phead; pn != NULL; pn = pn->next)
+		*lp++ = pn;
 	(void)qsort(list, entries, sizeof(PERSON *), psort);
 	return(list);
 }
@@ -117,16 +122,12 @@ psort(p, t)
 	return(strcmp((*p)->name, (*t)->name));
 }
 
-stimeprint(pn)
-	PERSON *pn;
+stimeprint(w)
+	WHERE *w;
 {
 	register struct tm *delta;
 
-	if (pn->info != LOGGEDIN) {
-		(void)printf("     ");
-		return;
-	}
-	delta = gmtime(&pn->idletime);
+	delta = gmtime(&w->idletime);
 	if (!delta->tm_yday)
 		if (!delta->tm_hour)
 			if (!delta->tm_min)
diff --git a/usr/src/usr.bin/finger/util.c b/usr/src/usr.bin/finger/util.c
index 2663b23419..5aeebf1b7c 100644
--- a/usr/src/usr.bin/finger/util.c
+++ b/usr/src/usr.bin/finger/util.c
@@ -19,7 +19,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)util.c	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)util.c	5.2 (Berkeley) %G%";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -31,24 +31,24 @@ static char sccsid[] = "@(#)util.c	5.1 (Berkeley) %G%";
 #include "finger.h"
 #include "pathnames.h"
 
-find_idle_and_ttywrite(pn)
-	register PERSON *pn;
+find_idle_and_ttywrite(w)
+	register WHERE *w;
 {
 	extern time_t now;
 	extern int errno;
 	struct stat sb;
 	char *strerror();
 
-	(void)sprintf(tbuf, "%s/%s", _PATH_DEV, pn->tty);
+	(void)sprintf(tbuf, "%s/%s", _PATH_DEV, w->tty);
 	if (stat(tbuf, &sb) < 0) {
 		(void)fprintf(stderr,
 		    "finger: %s: %s\n", tbuf, strerror(errno));
 		exit(1);
 	}
-	pn->idletime = now < sb.st_atime ? 0 : now - sb.st_atime;
+	w->idletime = now < sb.st_atime ? 0 : now - sb.st_atime;
 
 #define	TALKABLE	0220		/* tty is writable if 220 mode */
-	pn->writable = ((sb.st_mode & TALKABLE) == TALKABLE);
+	w->writable = ((sb.st_mode & TALKABLE) == TALKABLE);
 }
 
 userinfo(pn, pw)
@@ -116,38 +116,156 @@ match(pw, user)
 	return(0);
 }
 
-find_when(pn)
+enter_lastlog(pn)
 	register PERSON *pn;
 {
+	register WHERE *w;
 	static int fd;
 	struct lastlog ll;
+	char doit = 0;
 	off_t lseek();
 
-	if (!fd && (fd = open(_PATH_LASTLOG, O_RDONLY, 0)) < 0) {
-		(void)fprintf(stderr,
-		    "finger: %s: open error\n", _PATH_LASTLOG);
-		exit(1);
+	/*
+	 * Some systems may choose not to keep lastlog,
+	 * so we don't report any errors.
+	 * Not only that, we leave fd at -1 so lseek and read
+	 * will fail and act like there were no last logins.
+	 * Not the fastest way to do it, but what the hell.
+	 */
+	if (fd == 0)
+		fd = open(_PATH_LASTLOG, O_RDONLY, 0);
+	(void) lseek(fd, (long) (pn->uid * sizeof ll), L_SET);
+	if (read(fd, (char *)&ll, sizeof ll) != sizeof ll) {
+		/* same as never logged in */
+		ll.ll_line[0] = 0;
+		ll.ll_host[0] = 0;
+		ll.ll_time = 0;
 	}
-	(void)lseek(fd, (long)(pn->uid * (sizeof(ll))), L_SET);
-	if (read(fd, (char *)&ll, sizeof(ll)) != sizeof(ll)) {
-		(void)fprintf(stderr,
-		    "finger: %s: read error\n", _PATH_LASTLOG);
-		exit(1);
+	if ((w = pn->whead) == NULL)
+		doit = 1;
+	else {
+		/* if last login is earlier than some current login */
+		for (; !doit && w != NULL; w = w->next)
+			if (w->info == LOGGEDIN && w->loginat < ll.ll_time)
+				doit = 1;
+		/*
+		 * and if it's not any of the current logins
+		 * can't use time comparison because there may be a small
+		 * discrepency since login calls time() twice
+		 */
+		for (w = pn->whead; doit && w != NULL; w = w->next)
+			if (w->info == LOGGEDIN &&
+			    strncmp(w->tty, ll.ll_line, UT_LINESIZE) == 0)
+				doit = 0;
+	}
+	if (doit) {
+		w = walloc(pn);
+		w->info = LASTLOG;
+		bcopy(ll.ll_line, w->tty, UT_LINESIZE);
+		w->tty[UT_LINESIZE] = 0;
+		bcopy(ll.ll_host, w->host, UT_HOSTSIZE);
+		w->host[UT_HOSTSIZE] = 0;
+		w->loginat = ll.ll_time;
 	}
-	bcopy(ll.ll_line, pn->tty, UT_LINESIZE);
-	pn->tty[UT_LINESIZE] = NULL;
-	bcopy(ll.ll_host, pn->host, UT_HOSTSIZE);
-	pn->host[UT_HOSTSIZE] = NULL;
-	pn->loginat = ll.ll_time;
 }
 
-utcopy(ut, pn)
+enter_where(ut, pn)
 	struct utmp *ut;
 	PERSON *pn;
 {
-	bcopy(ut->ut_line, pn->tty, UT_LINESIZE);
-	pn->tty[UT_LINESIZE] = 0;
-	bcopy(ut->ut_host, pn->host, UT_HOSTSIZE);
-	pn->host[UT_HOSTSIZE] = 0;
-	pn->loginat = (time_t)ut->ut_time;
+	register WHERE *w = walloc(pn);
+
+	w->info = LOGGEDIN;
+	bcopy(ut->ut_line, w->tty, UT_LINESIZE);
+	w->tty[UT_LINESIZE] = 0;
+	bcopy(ut->ut_host, w->host, UT_HOSTSIZE);
+	w->host[UT_HOSTSIZE] = 0;
+	w->loginat = (time_t)ut->ut_time;
+	find_idle_and_ttywrite(w);
+}
+
+PERSON *
+enter_person(pw)
+	register struct passwd *pw;
+{
+	register PERSON *pn, **pp;
+
+	for (pp = htab + hash(pw->pw_name);
+	     *pp != NULL && strcmp((*pp)->name, pw->pw_name) != 0;
+	     pp = &(*pp)->hlink)
+		;
+	if ((pn = *pp) == NULL) {
+		pn = palloc();
+		entries++;
+		if (phead == NULL)
+			phead = ptail = pn;
+		else {
+			ptail->next = pn;
+			ptail = pn;
+		}
+		pn->next = NULL;
+		pn->hlink = NULL;
+		*pp = pn;
+		userinfo(pn, pw);
+		pn->whead = NULL;
+	}
+	return(pn);
+}
+
+PERSON *
+find_person(name)
+	char *name;
+{
+	register PERSON *pn;
+
+	/* name may be only UT_NAMESIZE long and not terminated */
+	for (pn = htab[hash(name)];
+	     pn != NULL && strncmp(pn->name, name, UT_NAMESIZE) != 0;
+	     pn = pn->hlink)
+		;
+	return(pn);
+}
+
+hash(name)
+	register char *name;
+{
+	register int h, i;
+
+	h = 0;
+	/* name may be only UT_NAMESIZE long and not terminated */
+	for (i = UT_NAMESIZE; --i >= 0 && *name;)
+		h = ((h << 2 | h >> HBITS - 2) ^ *name++) & HMASK;
+	return(h);
+}
+
+PERSON *
+palloc()
+{
+	PERSON *p;
+
+	if ((p = (PERSON *)malloc((u_int) sizeof(PERSON))) == NULL) {
+		(void)fprintf(stderr, "finger: out of space.\n");
+		exit(1);
+	}
+	return(p);
+}
+
+WHERE *
+walloc(pn)
+	register PERSON *pn;
+{
+	register WHERE *w;
+
+	if ((w = (WHERE *)malloc((u_int) sizeof(WHERE))) == NULL) {
+		(void)fprintf(stderr, "finger: out of space.\n");
+		exit(1);
+	}
+	if (pn->whead == NULL)
+		pn->whead = pn->wtail = w;
+	else {
+		pn->wtail->next = w;
+		pn->wtail = w;
+	}
+	w->next = NULL;
+	return(w);
 }
-- 
2.20.1