Usenet 1994 October/usenetsourcesnewsgroupsinfomagicoctober1994disk2.iso/misc/volume5/peerssa

Internet Message Format | 1989-02-03 | 5KB

Path: xanth!nic.MR.NET!hal!ncoast!allbery
From: [e-mail] (Brandon S. Allbery)
Newsgroups: comp.sources.misc
Subject: v05i091: peerssa -- a checker script in perl
Message-ID: <[e-mail]>
Date: 23 Dec 88 01:26:17 GMT
Sender: [e-mail]
Reply-To: [e-mail] (Brandon S. Allbery)
Organization: Cleveland Public Access UN*X, Cleveland, Oh
Lines: 151
Approved: [e-mail]

Posting-number: Volume 5, Issue 91
Submitted-by: "Brandon S. Allbery" <[e-mail]>
Archive-name: peerssa

This is a perl script I whipped up to check the status of ncoast when I log
in.  It may not be in the best form it could be; it suffers from having been
written when perl wasn't working right on ncoast (courtesy of a botched C
compiler).  However, it's useful as it is.

It can be invoked with the name of a checker script, or will default to the
file ~/.checklist if a script is not specified.  An example checker script is
below:

#
# Checklist for Peerssa:  The Checker
#

"df|" /([^     ]+).*[     ][     ]*(([0-9]?[0-9])?[0-9]) blocks/ + "WARNING: $2 BLOCKS FREE ON $1"
  |   /([^     ]+).*[     ][     ]*(([0-9]?[0-9])?[0-9]) inodes/ + "WARNING: $2 INODES FREE ON $1"
"ps -e|" /expire/ "Expire is running."
"/bin/who|" /^rhg / "The Boss is on the system."
    |       /^hal / "We are receiving news and mail."
/etc/inittab /^2:13:c:/ "The system is in Night/Weekend mode."

The format of the file is:

        source pattern [opcode] message

The source may be quoted, the message must be quoted.  Escaped quotes are
handled in all quoted strings.  At present, the pattern must be enclosed in
slashes, although I intend to change this.  A source followed by a pipe
character is considered to be a program or pipeline to be run to produce
input, just as in perl itself.  A source consisting of a single pipe
character signifies an additional pattern for use with the preceding source.
When the message is printed, variables $0-$9 are substituted from the pattern
by the same rules as for perl's $0-$9 variables.

The opcodes are:

    = (default)    print message for first matching line
    +        print message for all matching lines
    -        print message if NO matching lines

In the latter case, $0-$9 are not substituted.

#! /bin/sh
# This file was wrapped with "dummyshar".  "sh" this file to extract.
# Contents:  peerssa
echo extracting 'peerssa'
if test -f 'peerssa' -a -z "$1"; then echo Not overwriting 'peerssa'; else
sed 's/^X//' << \EOF > 'peerssa'
Xeval "exec perl -S $0 $*"
X    if $execed_by_shell;
X
X#
X# Peerssa:  The Checker
X# A perl script by Brandon S. Allbery
X# I hereby place this program in the public domain
X#
X# Scan a list of files or processes for specified patterns, and print messages
X# based on those patterns.  This is in some ways similar to "file" under
X# System V, but using patterns instead of fixed offsets and values.  I use it
X# to monitor certain critical system values, and certain things important to
X# me.
X#
X# If you don't understand the name, read Larry Niven's short story "Rammer".
X#
X
X# The file containing things to check for
X$checklist = $ENV{"HOME"} . "/.checklist";
X
X$npat = 0;
X$l = 0;
X$program = $0;
Xopen checklist;
Xwhile (<checklist>) {
X    $l++;
X    chop;
X# skip blank lines or comments
X    next if /^#/ || /^[ \t]*$/;
X    $line = $_;
X    do check() if $npat != 0 && $_ !~ /[     ]*\|[     ]/;
X# file-or-process /pattern/ [op] "message"
X# "file or process" /pattern/ [op] "message"
X# | /pattern/ [op] "message"    -- continue command
X# op is:  "=" match once, "+" match multiple, "!" print on no match
X    if ($line !~ m#^[ \t]*"(([^"]*\\")*[^"]*)"[ \t]+/(([^/]*\\/)*[^/]*)/[ \t]*([=!+]?)[ \t]*"(([^"]*\\")*[^"]*)"[ \t]*$#) {
X        if ($line !~ m#^[ \t]*([^ \t]+)[ \t]+/(([^/]*\\/)*[^/]*)/[ \t]*([=!+]?)[ \t]*"(([^"]*\\")*[^"]*)"[ \t]*$#) {
X            print "$program: syntax error on line $l of \"$checklist\"\n";
X            exit;
X        }
X        else {
X            $cf = $1;
X            $pat = $2;
X            $opr = $4;
X            $msg = $5;
X            die "$program: no previous pattern on line $l of \"$checklist\"\n" if $cf eq '|' & $npat == 0;
X            $checkfile = $cf if $cf ne '|';
X        }
X    }
X    else {
X        $checkfile = $1;
X# remove escaped quotes on filename
X        $checkfile =~ s/\\"/"/g;
X        $pat = $3;
X        $opr = $5;
X        $msg = $6;
X    }
X# default op is "="
X    $opr = "=" if $opr eq "";
X# remove escaped quotes on pattern and message
X    $pat =~ s#\\/#/#g;
X    $msg =~ s/\\"/"/g;
X# assign into array of [op, pat, message]
X    $pattern[$npat] = $pat;
X    $op[$npat] = $opr;
X    $message[$npat] = $msg;
X    $npat++;
X}
Xexit if $npat == 0;
Xdo check();
Xexit(0);
X
Xsub check {
X    local ($matched, $cnt);
X
X    open checkfile;
X    $matched = 0;
X    while (<checkfile>) {
X        for ($cnt = 0; $cnt < $npat; $cnt++) {
X            if ($_ =~ $pattern[$cnt]) {
X                $matched = 1;
X# the "eval" lets us print $1-$9 from the pattern, for customized messages
X                eval 'print "' . $message[$cnt] . "\n" . '"' if $op[$cnt] ne '!';
X                last if $op[$cnt] ne '+';
X            }
X        }
X    }
X    close checkfile;
X    print $message[0] . "\n" if !$matched & $op[0] eq '!';
X}
EOF
chars=`wc -c < 'peerssa'`
if test $chars !=    2544; then echo 'peerssa' is $chars characters, should be    2544 characters!; fi
fi
exit 0
--
Brandon S. Allbery, comp.sources.misc moderator and one admin of ncoast PA UN*X
uunet!hal.cwru.edu!ncoast!allbery            ncoast![e-mail]
comp.sources.misc is moving off ncoast -- please do NOT send submissions direct
      Send comp.sources.misc submissions to comp-sources-misc@<backbone>.