Backout previous commit, there are still some issues with it.

ok sthen@

3 files changed, 83 insertions, 189 deletions

diff --git a/usr.bin/tail/extern.h b/usr.bin/tail/extern.h
index 1cda5b85cfd..948f4e49bb0 100644
--- a/usr.bin/tail/extern.h
+++ b/usr.bin/tail/extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: extern.h,v 1.10 2008/10/17 11:38:20 landry Exp $	*/
+/*	$OpenBSD: extern.h,v 1.11 2008/11/13 18:33:03 landry Exp $	*/
 /*	$NetBSD: extern.h,v 1.3 1994/11/23 07:42:00 jtc Exp $	*/
 
 /*-
@@ -40,7 +40,6 @@ enum STYLE { NOTSET = 0, FBYTES, FLINES, RBYTES, RLINES, REVERSE };
 
 void forward(FILE *, enum STYLE, off_t, struct stat *);
 void reverse(FILE *, enum STYLE, off_t, struct stat *);
-void follow(char **, int, enum STYLE, off_t);
 
 int bytes(FILE *, off_t);
 int lines(FILE *, off_t);
diff --git a/usr.bin/tail/forward.c b/usr.bin/tail/forward.c
index e36498d9285..47cba10d3a3 100644
--- a/usr.bin/tail/forward.c
+++ b/usr.bin/tail/forward.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: forward.c,v 1.24 2008/10/17 11:38:20 landry Exp $	*/
+/*	$OpenBSD: forward.c,v 1.25 2008/11/13 18:33:03 landry Exp $	*/
 /*	$NetBSD: forward.c,v 1.7 1996/02/13 16:49:10 ghudson Exp $	*/
 
 /*-
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)forward.c	8.1 (Berkeley) 6/6/93";
 #endif
-static char rcsid[] = "$OpenBSD: forward.c,v 1.24 2008/10/17 11:38:20 landry Exp $";
+static char rcsid[] = "$OpenBSD: forward.c,v 1.25 2008/11/13 18:33:03 landry Exp $";
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -48,7 +48,6 @@ static char rcsid[] = "$OpenBSD: forward.c,v 1.24 2008/10/17 11:38:20 landry Exp
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
-#include <stdlib.h>
 
 #include "extern.h"
 
@@ -80,6 +79,9 @@ void
 forward(FILE *fp, enum STYLE style, off_t off, struct stat *sbp)
 {
 	int ch;
+	struct stat nsb;
+	int kq, queue;
+	struct kevent ke;
 
 	switch(style) {
 	case FBYTES:
@@ -158,188 +160,83 @@ forward(FILE *fp, enum STYLE style, off_t off, struct stat *sbp)
 		break;
 	}
 
-	while (!feof(fp) && (ch = getc(fp)) != EOF)
-		if (putchar(ch) == EOF)
-			oerr();
-	if (ferror(fp)) {
-		ierr();
-		return;
-	}
-	(void)fflush(stdout);
-}
-
-struct file_info {
-	FILE *fp;
-	char *fname;
-	struct stat fst;
-};
-
-/*
- * follow one or multiple files, i.e don't stop when end-of-file is reached,
- * but rather wait for additional data to be appended to the input.
- * this implements -f switch.
- */
-void
-follow(char **fnames, int nbfiles, enum STYLE style, off_t off)
-{
-	int ch, first, i;
-	int kq;
-	struct kevent ke;
-	struct stat cst;
-	FILE *fp;
-	struct file_info *files;
-
 	kq = -1;
-	if ((kq = kqueue()) < 0)
-		err(2, "kqueue() failed");
-
-	if ((files = calloc(nbfiles, sizeof(struct file_info))) == NULL)
-		err(1, "calloc() failed");
-
-	for (first = 1, i = 0; (files[i].fname = *fnames++); i++) {
-		if ((fp = fopen(files[i].fname, "r")) == NULL ||
-		    fstat(fileno(fp), &(files[i].fst))) {
-			warn("%s",files[i].fname);
-			nbfiles--;
-			i--;
-			continue;
-		}
-		if (S_ISDIR(files[i].fst.st_mode)) {
-			warnx("%s is a directory, skipping.",files[i].fname);
-			nbfiles--;
-			i--;
-			continue;
-		}
-		files[i].fp = fp;
-		if (nbfiles > 1) {
-			(void)printf("%s==> %s <==\n",
-			    first ? "" : "\n", files[i].fname);
-			first = 0;
-		}
-
-		/* print from the given offset to the end */
-		if (off != 0) {
-			if (style == RBYTES) {
-				if (S_ISREG(files[i].fst.st_mode)) {
-					if (files[i].fst.st_size >= off &&
-					    fseeko(fp, -off, SEEK_END) == -1) {
-						ierr();
-						goto cleanup;
-					}
-				}
-				if (bytes(fp, off))
-					goto cleanup;
-			} else if (rlines(fp, off, &(files[i].fst)) != 0)
-				lines(fp, off);
-		}
-		(void)fflush(stdout);
-
-		/* one event to see if there is data to read */
-		ke.ident = fileno(fp);
+kq_retry:
+	if (fflag && ((kq = kqueue()) >= 0)) {
 		EV_SET(&ke, fileno(fp), EVFILT_READ,
 		    EV_ENABLE | EV_ADD | EV_CLEAR,
-		    NULL, 0, NULL);
-		if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0)
-			goto cleanup;
-		else if (S_ISREG(files[i].fst.st_mode)) {
-			/* one event to detect if inode changed */
+		    0,
+		    0, NULL);
+		if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
+			close(kq);
+			kq = -1;
+		} else if (S_ISREG(sbp->st_mode)) {
 			EV_SET(&ke, fileno(fp), EVFILT_VNODE,
 			    EV_ENABLE | EV_ADD | EV_CLEAR,
 			    NOTE_DELETE | NOTE_RENAME | NOTE_TRUNCATE,
 			    0, NULL);
-			if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0)
-				goto cleanup;
+			if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
+				close(kq);
+				kq = -1;
+			}
 		}
 	}
 
-	/* no files to read */
-	if (nbfiles == 0)
-		goto cleanup;
-
-	if (fp == NULL)
-		fp = files[nbfiles - 1].fp;
-
 	for (;;) {
 		while (!feof(fp) && (ch = getc(fp)) != EOF)
 			if (putchar(ch) == EOF)
 				oerr();
-		if (ferror(fp))
-			goto cleanup;
-
+		if (ferror(fp)) {
+			ierr();
+			if (kq != -1)
+				close(kq);
+			return;
+		}
 		(void)fflush(stdout);
+		if (!fflag)
+			break;
 		clearerr(fp);
-		/* give it a chance to fail.. */
-		if (kevent(kq, NULL, 0, &ke, 1, NULL) <= 0) {
+		queue = 1;
+		if (kq < 0 || kevent(kq, NULL, 0, &ke, 1, NULL) <= 0) {
+			queue = 0;
 			sleep(1);
+		} else if (ke.filter == EVFILT_READ) {
 			continue;
-		} else {
-			/* an event occured on file #i */
-			for (i = 0 ; i < nbfiles ; i++)
-				if (fileno(files[i].fp) == ke.ident)
-					break;
+		} else if ((ke.fflags & NOTE_TRUNCATE) == 0) {
+			/*
+			 * File was renamed or deleted.
+			 *
+			 * Continue to look at it until a new file reappears
+			 * with the same name. 
+			 * Fall back to the old algorithm for that.
+			 */
+			close(kq);
+			kq = -1;
+		}
 
-			/* EVFILT_READ event, check that it's on the current fp */
-			if (ke.filter == EVFILT_READ) {
-				if (fp != files[i].fp) {
-					(void)printf("\n==> %s <==\n",files[i].fname);
-					fp = files[i].fp;
-					clearerr(fp);
-				}
-			/* EVFILT_VNODE event and File was renamed or deleted */
-			} else if (ke.fflags & (NOTE_DELETE | NOTE_RENAME)) {
-				/* file didn't reappear */
-				if (stat(files[i].fname, &cst) != 0) {
-					warnx("%s has been renamed or deleted.", files[i].fname);
-					if (--nbfiles == 0)
-						goto cleanup;
-					/* overwrite with the latest file_info */
-					fp = files[nbfiles].fp;
-					(void)memcpy(&files[i], &files[nbfiles], sizeof(struct file_info));
-				} else {
-					/* Reopen file if the inode changed */
-					if (cst.st_ino != files[i].fst.st_ino) {
-						warnx("%s has been replaced, reopening.", files[i].fname);
-						if ((fp = freopen(files[i].fname, "r", files[i].fp)) == NULL) {
-							ierr();
-							goto cleanup;
-						}
-						/*
-						 * on freopen(), events corresponding to the fp
-						 * were deleted from kqueue, we readd them
-						*/
-						ke.ident = fileno(fp);
-						EV_SET(&ke, fileno(fp), EVFILT_READ,
-						    EV_ENABLE | EV_ADD | EV_CLEAR,
-						    NULL, 0, NULL);
-						if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0)
-							goto cleanup;
-						else if (S_ISREG(files[i].fst.st_mode)) {
-							EV_SET(&ke, fileno(fp), EVFILT_VNODE,
-							    EV_ENABLE | EV_ADD | EV_CLEAR,
-							    NOTE_DELETE | NOTE_RENAME | NOTE_TRUNCATE,
-							    0, NULL);
-							if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0)
-								goto cleanup;
-						}
-						files[i].fp = fp;
-					}
-					(void)memcpy(&(files[i].fst), &cst, sizeof(cst));
-				}
-			} else if (ke.fflags & NOTE_TRUNCATE) {
-				/* reset file if it was truncated */
-				warnx("%s has been truncated, resetting.", files[i].fname);
-				fpurge(files[i].fp);
-				rewind(files[i].fp);
-				continue;
+		if (is_stdin || stat(fname, &nsb) != 0)
+			continue;
+		/* Reopen file if the inode changes or file was truncated */
+		if (nsb.st_ino != sbp->st_ino) {
+			warnx("%s has been replaced, reopening.", fname);
+			if ((fp = freopen(fname, "r", fp)) == NULL) {
+				ierr();
+				if (kq >= 0)
+					close(kq);
+				return;
 			}
+			(void)memcpy(sbp, &nsb, sizeof(nsb));
+			goto kq_retry;
+		} else if ((queue && (ke.fflags & NOTE_TRUNCATE)) ||
+		    (!queue && nsb.st_size < sbp->st_size)) {
+			warnx("%s has been truncated, resetting.", fname);
+			fpurge(fp);
+			rewind(fp);
 		}
+		(void)memcpy(sbp, &nsb, sizeof(nsb));
 	}
-
-cleanup:
 	if (kq >= 0)
 		close(kq);
-	free(files);
-	return;
 }
 
 /*
diff --git a/usr.bin/tail/tail.c b/usr.bin/tail/tail.c
index 10d164290cd..c0aa35c725b 100644
--- a/usr.bin/tail/tail.c
+++ b/usr.bin/tail/tail.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tail.c,v 1.15 2008/10/17 11:38:20 landry Exp $	*/
+/*	$OpenBSD: tail.c,v 1.16 2008/11/13 18:33:03 landry Exp $	*/
 
 /*-
  * Copyright (c) 1991, 1993
@@ -42,7 +42,7 @@ static char copyright[] =
 #if 0
 static char sccsid[] = "@(#)tail.c	8.1 (Berkeley) 6/6/93";
 #endif
-static char rcsid[] = "$OpenBSD: tail.c,v 1.15 2008/10/17 11:38:20 landry Exp $";
+static char rcsid[] = "$OpenBSD: tail.c,v 1.16 2008/11/13 18:33:03 landry Exp $";
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -132,6 +132,10 @@ main(int argc, char *argv[])
 		}
 	argc -= optind;
 	argv += optind;
+
+	if (fflag && argc > 1)
+		errx(1, "-f option only appropriate for a single file");
+
 	/*
 	 * If displaying in reverse, don't permit follow option, and convert
 	 * style values.
@@ -158,33 +162,27 @@ main(int argc, char *argv[])
 			style = RLINES;
 		}
 	}
-	
-	if (*argv) {
-		if (fflag) {
-			follow(argv, argc, style, off);
-		}
-		else {	
-			for (first = 1; (fname = *argv++);) {
-				if ((fp = fopen(fname, "r")) == NULL ||
-				    fstat(fileno(fp), &sb)) {
-					ierr();
-					continue;
-				}
-				if (argc > 1) {
-					(void)printf("%s==> %s <==\n",
-					    first ? "" : "\n", fname);
-					first = 0;
-					(void)fflush(stdout);
-				}
 
-				if (rflag)
-					reverse(fp, style, off, &sb);
-				else
-					forward(fp, style, off, &sb);
-				(void)fclose(fp);
+	if (*argv)
+		for (first = 1; (fname = *argv++);) {
+			if ((fp = fopen(fname, "r")) == NULL ||
+			    fstat(fileno(fp), &sb)) {
+				ierr();
+				continue;
 			}
+			if (argc > 1) {
+				(void)printf("%s==> %s <==\n",
+				    first ? "" : "\n", fname);
+				first = 0;
+				(void)fflush(stdout);
+			}
+
+			if (rflag)
+				reverse(fp, style, off, &sb);
+			else
+				forward(fp, style, off, &sb);
+			(void)fclose(fp);
 		}
-	}
 	else {
 		fname = "stdin";
 		is_stdin = 1;