Bash: Create a variable from several piped commands

Here’s how to put the result of several commands to a variable. This is quite useful.

> echo $(ls|sort|uniq|wc)
14 14 342

How much do you know about tar?

Tar could be one of most powerful and complex command which we need to use every day. Here some tips for tar

Find file and put them in to tar:

find ./ -name “*.jpg” | tar -cvf yourtar.tar -T -

or

tar -cvf yourtar.tar  `find *.c -print`

Bash Tip: Execute Command Inside Another Command

There is a way to embeded a command inside another command by using ` key. This key is on the left of 1 key

Example

tar -cvf aa.tar `find *.c -print`

This command finds all the *.c file and send it to aa.tar

Chmod recursively in directory

Chmod recursively in directory

remove execute from files under aa directory. This is useful when you copy files from fat or ntfs.

find aa/ -type f -exec chmod -x {} \;