How to rename multiple files

A simple problem:

Rename files with extension xyz which names ends with file. They need to start with document- and have extension txt For example if a file is 1-file.xyz it should be renamed to document-1.txt

From this:

> ls -al
total 0
drwxr-xr-x  12 owner  staff  384 Jan  1 19:26 .
drwxr-xr-x   7 owner  staff  224 Oct 23 11:32 ..
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 1-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 10-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 2-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 3-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 4-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 5-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 6-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 7-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 8-file.xyz
-rw-r--r--   1 owner  staff    0 Jan  1 19:26 9-file.xyz

to this:

> ls -al
total 0
drwxr-xr-x  12 owner  staff  384 Jan 12 22:39 .
drwxr-xr-x   7 owner  staff  224 Oct 23 11:32 ..
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-1.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-10.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-2.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-3.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-4.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-5.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-6.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-7.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-8.txt
-rw-r--r--   1 owner  staff    0 Jan 12 22:39 document-9.txt

Solution

I could grab any commander and go one by one. But that is one time solution. Plus, I know there will be more files like these.

To rename one from cli:

> mv 1-file.xyz document-1.txt

To do it on each file inside current directory:

for f in *.xyz; do mv $f "document-${f%-file.xyz}.txt";done

What is does?

For each file that ends with .xyz, remove its ending -file.xyz and insert it in template document-<file_name>.txt. Then rename current file.

Part "document-${f%-file.xyz}.txt" is made of two parts replacing -file.xyz then using result in the new filename. This part ${f%-file.xyz} is substring removal. Here it is how works:

Expression	Description
${PARAMETER#PATTERN}	Replacing pattern from the begging the shortest match
${PARAMETER##PATTERN}	Replacing pattern from the begging the longest match
${PARAMETER%PATTERN}	Replacing pattern from the end the shortest match
${PARAMETER%%PATTERN}	Replacing pattern from the end the longest match

Looking into this algorithm there are several steps:

locate target files by pattern
delete pattern from filename
add suffix and postfix on result from above
rename file

From all this I can write a simple script:

#!/bin/sh

PATTERN=$1
SUFIX=$2
POSTFIX=$3

cnt=0
for f in $(eval echo "*$PATTERN"); do
    mv "$f" "$SUFIX${f%$PATTERN}$POSTFIX"
    cnt=$((cnt + 1))
done;

echo "renamed $cnt files."

And to use this script, like this:

$rf.sh -file.xyz document- .txt

Code available at toolz

Solution#

Solution