How to rename a group of files with what looks like a Windows file path in their names

I just removed everything up to the last backslash with rename

$ rename -n 's/.*\\//' G*
rename(G:some\really\long\file\path\then\the\file_name.mov, file_name.mov)
rename(G:some\really\long\file\path\then\the\filename.txt, filename.txt)
rename(G:some\really\long\file\path\then\the\name1.jpg, name1.jpg)
rename(G:some\really\long\file\path\then\the\name2.png, name2.png)

Remove -n after testing to actually rename the files.

Notes

• -n don't do anything, just print what will be changed
• s/old/new replace old with new
• .* any number of any characters
• \\ The first backslash is to escape the second one.
• Since regex are greedy this expression .*\\ eats all the preceding backslashes too.
• Since the last two delimiters // are empty everything matched in the search part is deleted

You can do this in pure bash using shell parameter expansion.

${file##*\\} (cut-up-to-last-prefix) strips everything from the start of the filename until last \ seen.

for file in *; do
    mv -v "$file" "${file##*\\}";
done

The rename results are:

‘G:some\\really\\long\\file\\path\\then\\the\\file_name.mov’ -> ‘file_name.mov’
‘G:some\\really\\long\\file\\path\\then\\the\\filename.txt’ -> ‘filename.txt’
‘G:some\\really\\long\\file\\path\\then\\the\\name1.jpg’ -> ‘name1.jpg’
‘G:some\\really\\long\\file\\path\\then\\the\\name2.png’ -> ‘name2.png’