[src/trunk]: src/usr.bin/newsyslog Implement 'E' flag that prevents newsyslog...

[otis <otis%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/862452bdebd1
branches:  trunk
changeset: 953234:862452bdebd1
user:      otis <otis%NetBSD.org@localhost>
date:      Mon Mar 01 21:37:10 2021 +0000

description:
Implement 'E' flag that prevents newsyslog from rotating empty log files.

diffstat:

 usr.bin/newsyslog/newsyslog.8 |  11 +++++++++--
 usr.bin/newsyslog/newsyslog.c |  16 ++++++++++++++--
 2 files changed, 23 insertions(+), 4 deletions(-)

diffs (83 lines):

diff -r 1dbcf497dc48 -r 862452bdebd1 usr.bin/newsyslog/newsyslog.8
--- a/usr.bin/newsyslog/newsyslog.8     Mon Mar 01 21:01:39 2021 +0000
+++ b/usr.bin/newsyslog/newsyslog.8     Mon Mar 01 21:37:10 2021 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: newsyslog.8,v 1.41 2017/10/23 01:06:52 wiz Exp $
+.\"    $NetBSD: newsyslog.8,v 1.42 2021/03/01 21:37:10 otis Exp $
 .\"
 .\" Copyright (c) 1999, 2000 Andrew Doran <ad%NetBSD.org@localhost>
 .\" All rights reserved.
@@ -40,7 +40,7 @@
 .\"
 .\" from FreeBSD: newsyslog.8,v 1.14.2.1 1999/02/25 18:38:33 wollman Exp
 .\"
-.Dd June 16, 2012
+.Dd March 1, 2021
 .Dt NEWSYSLOG 8
 .Os
 .Sh NAME
@@ -313,6 +313,13 @@
 inserts to indicate that the logs have been trimmed should not be included.
 .It Sy c
 Create an empty log file if none currently exists.
+.It Sy e
+Do not rotate log file with zero size (empty).
+This flag is mostly usable in conjunction with
+.Ar b
+flag that prevents
+.Nm
+from inserting an ASCII informational message.
 .It Sy n
 No signal should be sent when the log is trimmed.
 .It Sy p
diff -r 1dbcf497dc48 -r 862452bdebd1 usr.bin/newsyslog/newsyslog.c
--- a/usr.bin/newsyslog/newsyslog.c     Mon Mar 01 21:01:39 2021 +0000
+++ b/usr.bin/newsyslog/newsyslog.c     Mon Mar 01 21:37:10 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: newsyslog.c,v 1.61 2013/09/05 11:34:40 prlw1 Exp $     */
+/*     $NetBSD: newsyslog.c,v 1.62 2021/03/01 21:37:10 otis Exp $      */
 
 /*
  * Copyright (c) 1999, 2000 Andrew Doran <ad%NetBSD.org@localhost>
@@ -55,7 +55,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: newsyslog.c,v 1.61 2013/09/05 11:34:40 prlw1 Exp $");
+__RCSID("$NetBSD: newsyslog.c,v 1.62 2021/03/01 21:37:10 otis Exp $");
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -94,6 +94,7 @@
 #define        CE_PLAIN0       0x10    /* Do not compress zero'th history file */
 #define        CE_SYSLPROTOCOL 0x20    /* log in syslog-protocol format,
                                   not configurable but detected at runtime */
+#define        CE_NOEMPTY      0x40    /* Do not rotate empty log file */
 
 struct conf_entry {
        uid_t   uid;                    /* Owner of log */
@@ -372,6 +373,9 @@
                case 'C':
                        log->flags |= CE_CREATE;
                        break;
+               case 'E':
+                       log->flags |= CE_NOEMPTY;
+                       break;
                case 'N':
                        log->flags |= CE_NOSIGNAL;
                        break;
@@ -462,6 +466,14 @@
                return;
        }
 
+       /* Skip rotation of empty log file when flag
+        * E is specified
+        */
+       if (sb.st_size == 0 && (log->flags & CE_NOEMPTY) != 0) {
+               PRHDRINFO(("empty file --> skip log\n"));
+               return;
+       }
+
        /* Size of the log file in kB. */
        size = ((size_t)sb.st_blocks * S_BLKSIZE) >> 10;