Rename multiple files in sub directories to their directory names

Question

I have a folder on my desktop named Models. In the folder, there are named folders with jpeg files without the .jpg extensions. The jpeg file names are random hashes. I would like to use a bash script to batch rename these jpeg files to their directory names with increments and append the .jpg extension on each file.

It's basically something like

Models/

 Alice/
      a5ccB2ff3e
      ee420bc4a
      2acee54dc
      ...
 Alex/
      de33fa24c0
      d1eaa48e0a
      ...

And I want to to be like

Models/

 Alice/
      Alice001.jpg
      Alice002.jpg
      Alice003.jpg
      ...

 Alex/
      Alex001.jpg
      Alex002.jpg
      ...

Answer 1

From the description of your question I am assuming that total no. of files in a folder does not exceed 999.

This is a simple bash script run it in your top directory i.e Models:

#!/bin/bash
for i in ./*
do
if [ -d "$i" ]
then
j=001
for k in "$i"/*
do
mv "$k" "$i"/"$i""$j".jpg
j=${j#0}
if [ ${j:0:1} -eq 0 ]
then 
j=${j#0}
fi
(( j++ ))
j=`printf '%03i' $j`
done
fi
done

It will first check every file in Models, whether it is a directory or not by if [ -d "$i" ] . Then for each file in this directory it will change their names by mv "$k" "$i"/"$i""$j".jpg. And

j=${j#0}
if [ ${j:0:1} -eq 0 ]
then 
j=${j#0}
fi

Above code will remove all the zeroes from beginning so that you will not get the error like:

 ((: 008: value too great for base (error token is "008")
 printf: 008: invalid octal number

And

j=`printf '%03i' $j`

will make value of j 3 digits long.

Answer 2

Try also this simplified version of Debian_yadav's proposal:

for i in *
  do    if [ -d "$i" ] && cd "$i"
          then  j=0
                for k in *
                  do    ((j++))
                        echo mv "$k" $(printf "%s%03d.jpg" $i $j )
                  done
                cd ..
          fi
  done

The echo is for debugging only; remove if happy with what you see.

It cds into each directory available, resets the counter, loops across all target files, increments the counter for each, and the does the rename.