From bac92875e5f1703041986379c9c0d7d3588228ff Mon Sep 17 00:00:00 2001
From: Dirk Koopman <djk@tobit.co.uk>
Date: Thu, 3 Feb 2022 14:55:57 +0000
Subject: [PATCH] improve help for grepdbg and watchdbg

---
 Changes           |  2 ++
 perl/DXChannel.pm |  2 +-
 perl/grepdbg      | 21 +++++++++++++++------
 perl/watchdbg     | 33 ++++++++++++++++++++++++++++++---
 4 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/Changes b/Changes
index 0f3234a3..e2f1c254 100644
--- a/Changes
+++ b/Changes
@@ -1,3 +1,5 @@
+03Feb22=======================================================================
+1. Improve/add the help text for grepdbg and watchdbg. 
 31Jan22=======================================================================
 1. Set $RBN::respottime to 3 minutes. NOTE change of name from 
    $RBN::minspottime.
diff --git a/perl/DXChannel.pm b/perl/DXChannel.pm
index 29919c7e..8b1792cd 100644
--- a/perl/DXChannel.pm
+++ b/perl/DXChannel.pm
@@ -719,7 +719,7 @@ sub process_one
 		if ($sort ne 'D') {
 			if (isdbg('chan')) {
 				if (($self->is_rbn && isdbg('rbnchan')) || !$self->is_rbn) {
-					dbg("<- $sort $call $line") if isdbg('chan');
+					dbg("<- $sort $call $line") if isdbg('chan'); # you may think this is tautology, but it's needed get the correct label on the debug line
 				}
 			}
 		}
diff --git a/perl/grepdbg b/perl/grepdbg
index f61d7cc1..8fa76857 100755
--- a/perl/grepdbg
+++ b/perl/grepdbg
@@ -8,8 +8,9 @@
 # nn - is the day you what to look at: 1 is yesterday, 0 is today
 # and is optional if there is only one argument
 #
-# -mmm - print the mmm lines before the match. So -10 will print
-# ten lines including the line matching the regular expression. 
+# -mmm - print the mmm lines before the match. So -3 will print
+# 4 lines altogether, the 3 lines before the line matching
+# the regular expression. 
 #
 # <regexp> is the regular expression you are searching for, 
 # a caseless search is done. There can be more than one <regexp>
@@ -60,7 +61,7 @@ foreach my $arg (@ARGV) {
 			usage();
 			exit(0);
 		}
-		$nolines = $arg if $arg =~ /^\d+$/;
+		$nolines += $arg if $arg =~ /^\d+$/;
 	} elsif ($arg =~ /^\d+$/) {
 		push @days, $arg;
 	} elsif ($arg =~ /\.pm$/) {
@@ -136,7 +137,7 @@ sub usage
 {
 	print << "XXX";
 
- usage: grepdbg [nn days before] [-nnn lines before] [<perl file name>] [<regexp>|!<regexp>]...
+ usage: grepdbg [nn days before] [-nnn lines before] [<perl filter module>] [<regexp>|!<regexp>]...
 
         You can have more than one <regexp> with an implicit 'and' between them. All 
         <regexes> are caseless. It's recommended to put 'not' (!<regex>) first in any list.
@@ -150,8 +151,13 @@ sub usage
 
         is a handy way of scrolling through the debug log.
 
+          grepdbg -2 progress
+
+        will display any line containing 'progress' and also the two lines before that.
+
         You can install your own content and display arrangement (useful for filtering data 
         in some complicated way). You call it like this (assuming it is called 'filter.pm').
+        This is what is meant by <perl filter module>.
 
         grepdbg filter.pm
 
@@ -174,8 +180,11 @@ sub usage
         You can also add a 'sub total {...}' which executes after the last line is 
         printed and grepdbg exits.
 
-        Read the code of this program and copy'n'paste the 'sub process' code and change 
-        its name to 'sub handle'. Modify it to your requirements... 
+        Read the code of this program and copy'n'paste the 'sub
+        process' code into a new file. Then change 'sub process'
+        to 'sub handle'. Add the line 'package main;' at the beginning
+        of the file and a line '1;' at the end and then modify it to
+        your requirements...
 
 XXX
 }
diff --git a/perl/watchdbg b/perl/watchdbg
index a497eff9..2b1986a7 100755
--- a/perl/watchdbg
+++ b/perl/watchdbg
@@ -37,11 +37,20 @@ my $fp = DXLog::new('debug', 'dat', 'd');
 my $today = $fp->unixtoj(time()); 
 my $fh = $fp->open($today) or die $!; 
 my $nolines = 1;
-$nolines = shift if $ARGV[0] =~ /^-?\d+$/;
-$nolines = abs $nolines if $nolines < 0;  
-my @patt = @ARGV;
+my @patt;
 my @prev;
 
+while (@ARGV) {
+	my $arg = shift;
+	if ($arg =~ /^-+(\d+)/) {
+		$nolines += $1;
+		next;
+	}
+	usage(), exit(0) if $arg =~ /^-+[h\?]/i;
+	push @patt, $arg;
+}
+
+
 # seek to end of file
 $fh->seek(0, 2);
 for (;;) {
@@ -98,3 +107,21 @@ sub printit
 	}
 }
 exit(0);
+
+sub usage
+{
+	print << "XXX";
+
+ usage: watchdbg [-nnn lines before] [<regexp>|!<regexp>]...
+
+        You can have more than one <regexp> with an implicit 'and' between them. All 
+        <regexes> are caseless. It's recommended to put 'not' (!<regex>) first in any list.
+        Don't forget that you are doing this in a shell and you may need to quote your
+        <regex>s.
+ 
+          watchdbg -2 progress
+
+        will display any line containing 'progress' and also the two lines before that.
+
+XXX
+}
-- 
2.43.0