greps for search word in directory and below (defaults to cd).

-i case insensitive

-n shows line number

-H shows file name

kills all pids matching the search term of "PROCESS". Be careful what you wish for :)

Note that the file at the given path will have the contents of the (still) deleted file, but it is a new file with a new node number; in other words, this restores the data, but it does not actually "undelete" the old file.

I posted a function declaration encapsulating this functionality to http://www.reddit.com/r/programming/comments/7yx6f/how_to_undelete_any_open_deleted_file_in_linux/c07sqwe (please excuse the crap formatting).

If the 'lm' flag is present, then the CPU is 64-bit.

If no output, then CPU is 32-bit.

From 'man netstat'

"netstat -i | -I interface [-abdnt] [-f address_family] [-M core] [-N system]

Show the state of all network interfaces or a single interface

which have been auto-configured (interfaces statically configured

into a system, but not located at boot time are not shown). An

asterisk (``*'') after an interface name indicates that the

interface is ``down''. If -a is also present, multicast

addresses currently in use are shown for each Ethernet interface

and for each IP interface address. Multicast addresses are shown

on separate lines following the interface address with which they

are associated. If -b is also present, show the number of bytes

in and out. If -d is also present, show the number of dropped

packets. If -t is also present, show the contents of watchdog

timers."

This is a nice way to kill processes.. the example here is for firefox!!! substitute firefox for whatever the process name is...

To save the result, redirect the output to another file.

convenience.

Useful to check DDoS attacks on servers.

Yet another ps grep function, but this one includes the column headings.

My variant on this common function. Some highlights:

Allows you to override the default ps args of "aux"

Uses bracket trick to omit the grep process itself without having to use a second grep

Always prints the correct header row of ps output

Limitations: Ugly ps error output if you forget to quote your multi word grep argument

This command takes the output of the 'last' command, removes empty lines, gets just the first field ($USERNAME), sort the $USERNAMES in reverse order and then gives a summary count of unique matches.

Searching for a String in Multiple Files With Grep

This will give you the Dell Service tag number associated with your machine. Incredibly useful when you need that number for tech support or downloads.

This command deletes all files in all subfolders if their name or path contains "deleteme".

To dry-run the command without actually deleting files run:

This is a 'killall' command equivalent where it is not available.

Prior to executing it, set the environment variable USERNAME to the username, whose processes you want to kill or replace the username with the $USERNAME on the command above.

Side effect: If any processes from other users, are running with a parameter of $USERNAME, they will be killed as well (assuming you are running this as root user)

[-9] in square brackets at the end of the command is optional and strongly suggested to be your last resort. I do not like to use it as the killed process leaves a lot of mess behind.

finds all forms instanciated into a symfony project, pruning svn files.