Working on exercise 5 on lab 8

Labb8/ovning5/failed_logins.sh

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+#!/bin/bash
+
+# Jack-Benny Persson
+# LX13
+# Exercise 5 on lab 8 (Write a script to check for failed logins)
+
+# Binaries
+Sed="/bin/sed"
+Awk="/usr/bin/awk"
+Egrep="/bin/egrep"
+Mail="/usr/bin/mail"
+Printf="/usr/bin/printf"
+
+# Variables
+Admin="jake"
+Authlog="/var/log/auth.log"
+
+# Sanity checks
+if [ ! -r $Authlog ]; then
+	echo "Can't read $Authlog"
+	exit 1
+fi
+
+for Bin in $Sed $Awk $Egrep $Mail $Printf; do
+	if [ ! -x $Bin ]; then
+		echo "Can't execute $Bin"
+		exit 1
+	fi
+done
+
+# Main
+
+# Print a nice header
+$Printf "Date & time\t\tUser\t\tFrom host\n"
+$Printf "-----------\t\t----\t\t---------\n"
+# Search for failed logins
+$Sed -n '1,$p' $Authlog | $Egrep "Failed password" | $Sed 's/invalid user//' | \
+$Awk '{ print $1" "$2" "$3" \t"$9"\t\t"$11 }'
+
+# Save the last line for next run (WORK IN PROGRESS)
+cat /var/log/auth.log | sed -n '/Dec 28 20:40:41/{
+=
+p
+}' | tail -n2 | sed -n '/^[0-9]/p' > /tmp/failed_login_last_line.tmp
+
+exit 0

Labb8/ovning5/last.sed

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+/Dec 28 20:40:41/p