Update and some new examples

* Update a mistake in ifconfig
* Add example for a SOCKS proxy in ssh
* Add an example for mounting a NFS dir in mount
* Add a description for git blame
* Add some examples in grep
* Add example for specifing an interface in dhclient
* Add a description for apt-get install
* Add some commands in apt-cache
* Add an example of pretty printing jsons using python

cheatsheets/apt-cache

@@ -3,3 +3,10 @@ apt-cache search "whatever"
 
 # To display package records for the named package(s):
 apt-cache show pkg(s)
+
+# To display reverse dependencies of a package
+apt-cache rdepends package_name
+
+# To display package versions, reverse dependencies and forward dependencies 
+# of a package
+apt-cache showpkg package_name

cheatsheets/apt-get

@@ -11,3 +11,6 @@ apt-get dist-upgrade
 
 # Full command:
 apt-get update && apt-get dist-upgrade
+
+# To install a new package(s)
+apt-get install package(s)

cheatsheets/dhclient

@@ -5,3 +5,6 @@ sudo dhclient -r
 sudo dhclient
 
 # Running the above in sequence is a common way of refreshing an IP.
+
+# To obtain a new IP address for a specific interface:
+sudo dhclient eth0

cheatsheets/git

@@ -26,6 +26,9 @@ git push git@github.com:username/project.git
 # To delete the branch "branch_name"
 git branch -D branch_name
 
+# To see who commited which line in a file
+git blame filename
+
 # To sync a fork with the master repo:
 git remote add upstream git@github.com:name/repo.git    # Set a new repo
 git remote -v                                           # Confirm new remote repo

cheatsheets/grep

@@ -10,6 +10,13 @@ grep -R pattern folder
 # Getting pattern from file (one by line):
 grep -f pattern_file file
 
+# Find lines NOT containing pattern
+grep -v pattern file
+
+# You can grep with regular expressions
+grep "^00" file  #Match lines starting with 00
+grep -E "[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}" file  #Find IP add
+
 # Find all files who contain {pattern} in the directory {directory}.
 # This will show: "file:line my research"
 grep -rnw 'directory' -e "pattern"

cheatsheets/ifconfig

@@ -5,9 +5,10 @@ ifconfig wlan0
 ifconfig -a
 
 # Take down / up the wireless adapter
-ifconfig {up|down} wlan0
+ifconfig wlan0 {up|down} 
 
 # Set a static IP and netmask
 ifconfig eth0 192.168.1.100 netmask 255.255.255.0
+
 # You may also need to add a gateway IP
 route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.1

cheatsheets/mount

@@ -3,3 +3,6 @@ mount -o remount,rw /
 
 # To mount Usb disk as user writable:
 mount -o uid=username,gid=usergroup /dev/sdx /mnt/xxx
+
+# To mount a remote NFS directory
+mount -t nfs example.com:/remote/example/dir /local/example/dir

cheatsheets/python

@@ -11,3 +11,6 @@ python -m http.server 8000
 
 # SMTP-Server for debugging, messages will be discarded, and printed on stdout.
 python -m smtpd -n -c DebuggingServer localhost:1025
+
+# Pretty print a json
+python -mjson.tool

cheatsheets/ssh

@@ -13,5 +13,8 @@ ssh -X user@example.com
 # To launch a specific x application over SSH:
 ssh -X -t user@example.com 'chromium-browser'
 
+# To create a SOCKS proxy on localhost and port 9999
+ssh -D 9999 user@example.com
+
 # For more information, see:
 # http://unix.stackexchange.com/q/12755/44856