将文件名的第一部分移到文件扩展名的末尾

Question

Got the following code which removes 1234- from the start of a file name

rename -v "s/^1234-//g" *.***

Input:

1234-test1.test2.jpg

Output:

test1.test2.jpg

And this bit of code which add -1234 to the end of the file name

for file in *.jpg; do echo $(basename $file .jpg)-1234; done

Input:

test1.test2.jpg

Output:

test1.test2-1234.jpg

I´m looking for a way to combine these 2 commands into one single script, but also somehow avoid the second bit of code to keep adding -1234 for every time its run once its there, if possible.

Answer 1

This assumes all the files are .jpg :

rename -v "s/^1234-(.+)(\.jpg)/$1-1234$2/" *.*

This matches the whole file name but captures just the part after 1234- in 2 groups. The $1 and $2 area back-references to the captured parts.

Answer 2

This would to it:

for file in *.jpg; do
   basename=${file%.*}               # Get the basename without using a subprocess.
   extension=${file##*.}             # Get the extension if you want to add *.JPG in the for, can be skipped if only *.jpg.

   newname=${basename#1234-}         # Remove "1234-" in front of basename.
   test "$basename" = "$newname" &&  # If basename did not start with "1234-", skip this file.
     continue  

   newname=${newname%-1234}          # Remove an eventual "-1234" at the end of newname.
   newname="${newname}-1234"         # Add "-1234" at the end of newname.
   newname="$newname.$extension"     # Restore extension.
   echo mv "$file" "$newname"        # echo rename command.
done

If you are happy with the output, remove the echo in the last line.