Rename multiple files based on pattern in Unix

Question

There are multiple files in a directory that begin with prefix fgh, for example:

fghfilea
fghfileb
fghfilec

I want to rename a

Answer 1

This worked for me using regexp:

I wanted files to be renamed like this:

file0001.txt -> 1.txt
ofile0002.txt -> 2.txt 
f_i_l_e0003.txt -> 3.txt

usig the [a-z|_]+0*([0-9]+.) regexp where ([0-9]+.) is a group substring to use on the rename command

ls -1 | awk 'match($0, /[a-z|\_]+0*([0-9]+.*)/, arr) { print   arr[0]  " "  arr[1] }'|xargs  -l mv

Produces:

mv file0001.txt 1.txt
mv ofile0002.txt 2.txt
mv f_i_l_e0003.txt 3.txt

Another example:

file001abc.txt -> abc1.txt
ofile0002abcd.txt -> abcd2.txt 

ls -1 | awk 'match($0, /[a-z|\_]+0*([0-9]+.*)([a-z]+)/, arr) { print   arr[0]  " "  arr[2] arr[1] }'|xargs  -l mv

Produces:

  mv file001abc.txt abc1.txt
  mv ofile0002abcd.txt abcd2.txt 

Warning, be careful.