Linux – Renaming files without file extensions

linuxrename

I have a series of files named KLLxxx (the x represents numbers). They're text files but have no file extension to them. Just files that say KLL followed by three digits. I want them all to end with the file extension .fastq. Such as KLL123 -> KLL123.fastq.

So I tried using this command

mv KLL* KLL*.fastq

But I keep on getting the error message:

mv: target 'KLL067.fastq' is not a directory

I know about the rename command function, but I've never used Perl before so I don't know how to approach this. I know this is a basic question, but this is my first time trying out Linux.

Best Answer

Running the following find command in the directory you are looking at will do the trick:

find . -name 'KLL[0-9][0-9][0-9]' -exec sh -c 'mv $0 $0.fastq' {} \;

Which will add the extension .fastq to any file name starting with KLL followed by three digits.

Related Solutions

Shell Scripting – How to Copy Multiple Files and Keep Their Extensions

You can use bash's string substitution features for that:

for file in /tmp/p/DSC*.JPG; do
  cp "$file" "${file%.JPG}"_orig.JPG
done

The general format is ${string%substring} which will remove substring from the end of string. For example:

$ f=foobar.JPG; echo "${f%.JPG}"
foobar

Shell – Move Last Part of Filename to Front

With the Perl rename ^(*):

rename 's/^(.*) - (.*)(\..*)$/$2 - $1$3/' *.avi

or, if you want to be stricter about the code:

rename 's/^(.*) - ([a-zA-Z]{2}\d{2}-\d{4})(\..*)$/$2 - $1$3/' *.avi

That should work even with names like foo - bar - AB12-1234.avi, since the first .* greedily matches up to the final <space><dash><space>.

_{(* see: What's with all the renames: prename, rename, file-rename?)}

Or similarly in Bash:

for f in *.avi ; do
    if [[ "$f" =~  ^(.*)\ -\ (.*)(\..*)$ ]]; then
        mv "$f" "${BASH_REMATCH[2]} - ${BASH_REMATCH[1]}${BASH_REMATCH[3]}"
    fi
done

Briefly, the regexes break down to

^     start of string
( )   capture group
.*    any amount of anything
\.    a literal dot
$     end of string

Most regular characters match themselves, though you need to escape spaces with backslashes in Bash (as above). The contents of the capture groups appear in order in $1, $2 etc in Perl, and in ${BASH_REMATCH[1]}, ${BASH_REMATCH[2]} etc in Bash.

Best Answer

Related Solutions

Shell Scripting – How to Copy Multiple Files and Keep Their Extensions

Shell – Move Last Part of Filename to Front

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