Linux Rename File: add suffix, replace space, lower and upper case

Need to rename all files in a directory using Linux shell? If so, this short article is exactly for you. All situations will be explained with example and explanation:

  • Add suffix or prefix to all files in folder
  • Replace spaces with underscores
  • change file names from Upper case to Lower

P.S. All examples assume that terminal is opened with the directory where the files are stored! If not you can do it by: cd /home/user or you can check the working folder by: pwd

Add suffix or prefix to all files in folder

In this example there are many files in a folder which doesn't have any extension. The goal is to update all files and add an extension as suffix. This can be done by next example:

for f in *; do
    mv "$f" "${f%}.txt"


my file name -> my file name.txt


  • List all files in the current folder - the * matches any file. You can list all files by pattern like: *.txt or song_*
  • Next line mv "$f" "${f%}.txt" add .txt as suffix to all files

The same logic applies if you need to add prefix or both.

Replace spaces with underscores for Linux files

Linux and some applications "doesn't like" spaces in files names. For example if you try to open a file by a command like: xed $file and the file contain spaces: my file name. You will end by xed opening: my, file and name or equivalent of: xed my, xed file, xed name. In order to avoid this you can replace all spaces from your file names by

find $1 -name "* *.txt" -type f -print0 | \
  while read -d $'\0' f; do 
 	mv -v "$f" "${f// /_}"; 


my file name.txt -> my_file_name.txt


  • List all text files with spaces (or change the pattern) in the current folder
  • line mv -v "$f" "${f// /_}"; is replacing all spaces find in the name by underscores by this pattern: ${f// /_}

Replace spaces with underscores for Linux files

Some websites and applications works with file names only in upper or lower case. In order to change the file name from any case to lower case only you can use next script:

for i in $( ls | grep [A-Z] ); do 
	mv -i $i `echo $i | tr 'A-Z' 'a-z'`; 


My_file_name.txt -> my_file_name.txt



  • ls | grep [A-Z] - this command will list all files and folders and will match only uppercase letters.
  • statement mv -i $i echo $i | tr 'A-Z' 'a-z'; will do the replacement for upper to lower case.

Note that last command might not work in cases of spaces in the file names.

More articles about file renaming

Share Tweet Send