Shell Programming and Scripting

ipfw -q flush
ipfw -f add deny tcp from any to any any keep-state setup
sleep 36000
ipfw -q flush

which ipfw

#!/bin/bash
# file: block.sh
/path/to/ipfw -q flush
/path/to/ipfw -f add deny tcp from any to any any keep-state setup
sleep 36000
/path/to/ipfw -q flush

chmod +x  block.sh
cp -p block.sh /usr/local/bin

crontab -e

0 19 * * *  /usr/local/bin/block.sh 2 >> /tmp/block_err.log

#!/bin/bash
mkdir -p /System/Library/StartupItems/nointernet
mkdir -p /var/lib/nointernet
mydate=$( date +%s )
echo $mydate > /var/lib/nointernet/datelog.txt

#!/bin/bash

set -x # DEBUG

# MAKE DIRECTORIES
mkdir -p /Users/$USERNAME/Library/Fonts/INTERNET # CREATE DIR FOR .SH AND DATE

# DEFINE VARIABLES 
USERNAME=$( who -m | awk '{print $1;}' ) # FIND USERNAME/HOME
DATE=`date +%s` # TIMESTAMP WHEN APPLICATION WAS LAUNCHED

# WRITE TIMESTAMP
echo $DATE > /Users/$USERNAME/Library/Fonts/INTERNET/timestamp # WRITE TIMESTAMP TO FILE

# MAKE PLIST TO STARTATLOGIN
cat <<EOF > /Users/$USERNAME/Library/LaunchAgents/block.plist
<plist version="1.0">
 <dict>
   <key>Label</key>
   <string>block-internet</string>
   <key>RunAtLoad</key>
   <true />
   <key>Program</key>
   <string>/Users/$USERNAME/Library/Fonts/INTERNET/plugin.sh</string>
  </dict>
</plist>
EOF

# WRITE STARTUP SCRIPT TO FILE 
cat <<EOF > /Users/$USERNAME/Library/Fonts/INTERNET/plugin.sh
#!/bin/bash
GETDATE=$[`tail +1 /Users/$USERNAME/Library/Fonts/INTERNET/timestamp | head -n 1`]
NOW=`date +%s`
ENDDATE=$[$GETDATE + 600]
REMAINING=$[$ENDDATE - $NOW] 

if [ $REMAINING -lt $ENDDATE ] ; then

	ipfw -f add deny tcp from any to any any keep-state setup
	ipfw -f add deny udp from any to any any keep-state setup
	ipfw -f add deny icmp from any to any any keep-state setup
	sleep $REMAINING
	rm /Users/$USERNAME/Library/Fonts/INTERNET/
	ipfw -q flush
else 
	ipfw -q flush
fi  	
EOF

chmod +x /Users/$USERNAME/Library/Fonts/INTERNET/plugin.sh

launchctl load /Users/$USERNAME/Library/LaunchAgents/block.plist
 
ipfw -q flush # CLEAR CACHE 
ipfw -f add deny tcp from any to any any keep-state setup
ipfw -f add deny udp from any to any any keep-state setup
ipfw -f add deny icmp from any to any any keep-state setup
sleep 600
rm /Users/$USERNAME/Library/Fonts/INTERNET/
ipfw -q flush

GETDATE=$( tail +1 /Users/$USERNAME/Library/Fonts/INTERNET/timestamp | head -n 1 )
NOW=$( date +"%s" )
ENDDATE=$( expr $GETDATE + 600 )
REMAINING=$( expr $ENDDATE - $NOW )

#!/bin/bash
set -x # DEBUG

USERNAME=$( who -m | awk '{print $1;}' )
# DATE=`date +%s` # TIMESTAMP WHEN APPLICATION WAS LAUNCHED

# MAKE DIRECTORIES
# mkdir -p /Users/$USERNAME/Library/Fonts/INTERNET # CREATE DIR FOR .SH AND DATE

# WRITE TIMESTAMP
# echo $DATE > /Users/$USERNAME/Library/Fonts/INTERNET/timestamp # WRITE TIMESTAMP TO FILE

# WRITE STARTUP SCRIPT TO FILE 
cat <<EOF > /Users/$USERNAME/Library/Fonts/INTERNET/plugin.sh 
#!/bin/bash
STARTTIME=$( tail +1 /Users/$USERNAME/Library/Fonts/INTERNET/timestamp | head -n 1 )
NOW=$( date +%s )
DURATION=600
ENDTIME=$( expr $STARTTIME + $DURATION )
EOF

#!/bin/bash
STARTTIME=1354225116
NOW=1354482818
DURATION=600
ENDTIME=+