Question

Now I have the rename script like this:

cd /Users/KanZ/Desktop/Project/Test/ 
n=1
for file in *.jpg; do 
    echo $file
    prefix=M
    file_name=M$n.jpg 
    echo $file_name
    n=$(( $n+1 ))
    mv $file $file_name 
done 

The first if I run script, the all of jpg files will be M1.jpg M2.jpg M3.jpg but if I add the new file name A1.jpg to this directory and run script again. All of M1.jpg M2.jpg M3.jpg will be replaced by M4.jpg(before run script, this file named A1.jpg) because the first letter is A. It come before M. This is my problem. I would like to get M1 M2 M3 M4.jpg and every time if there are new files coming, this script will generate the continue name like M5.jpg M6.jpg . How is the code look like? Hope you understand that. Thank u for helping

Answer 1

This little script will do it.

cd /Users/KanZ/Desktop/Project/Test/ 
n=$(ls -1 | grep '^M' -c)                    # find the number for M files 
ls -1 *.jpg| grep -v '^M' | while read file  # for each of the non-M files
do 
   n=$(($n+1));                       
   new_file=M$n.jpg                          # new name with next available M file name
   mv "$file" "$new_file"                        # rename with new file name
done 

See how it works.

test/rename$ for x in 1 2 3; do echo A$x> A$x.jpg; done;
test/rename$ ls
A1.jpg  A2.jpg  A3.jpg
test/rename$ cat ../rnm.sh 
#!/bin/bash
cd "$1"
n=$(ls -1 | grep '^M' -c)
nfiles=$(ls -1 *.jpg| grep -v '^M');
for file in $nfiles;
do 
   n=$(($n+1));
   new_file=M$n.jpg
   mv $file $new_file
done 
test/rename$ bash ../rnm.sh  ./
test/rename$ ls
M1.jpg  M2.jpg  M3.jpg
test/rename$ for x in 1 2 ; do echo B$x> B$x.jpg; done;
test/rename$ ls
B1.jpg  B2.jpg  M1.jpg  M2.jpg  M3.jpg
test/rename$ bash ../rnm.sh  ./
test/rename$ ls
M1.jpg  M2.jpg  M3.jpg  M4.jpg  M5.jpg
test/rename$ for x in *.jpg; do echo $x; cat $x; done;
M1.jpg
A1
M2.jpg
A2
M3.jpg
A3
M4.jpg
B1
M5.jpg
B2