Batch rename folders with a single bash command

Question

I have folders setup like this:

/path/to/directory/SLUG_1/SLUG_1 - SLUG_2 - SLUG_3

SLUG_2 is a year, and it may have a letter after the year, like "1994" or "2003a".

I would like to rename those files to:

/path/to/directory/SLUG_1/SLUG_2 - SLUG_3

I'm getting pretty close with this command:

find $root -mindepth 2 -maxdeth 2 -type d | sed "s#\(\(/path/to/directory/[^/]*/\).* - \([0-9]\{4\}[a-bA-B]\? - .*\)\)#mv "\1" "\2\3"#

This prints:

mv "/path/to/directory/SLUG_1/SLUG_1 - SLUG_2 - SLUG_3" "/path/to/directory/SLUG_1/SLUG_2 - SLUG_3"

Which is exactly the command I want to execute. But I can't execute it.

I tried assigning the output to a variable and executing it by calling the variable. That didn't work. I tried a few variations on that idea, and I got errors.

It feels like I'm missing some tool here. Some iterating tool that makes this job easy. Any suggestions?

Answer 1

This prints:

mv ...

Which is exactly the command I want to execute. But I can't execute it.

I tried assigning the output to a variable and executing it by calling the variable. That didn't work. I tried a few variations on that idea, and I got errors.

It feels like I'm missing some tool here.

The easy way you are looking for is to append | bash to your command. That's how you can go from "a command which prints a command" to "actually running the command that was printed."

However, even though you've included double quotes in the command to be printed, this is a bad idea to include in a script.

• Why does my shell script choke on whitespace or other special characters?

You may have handled the whitespace aspect, but what if the filenames include double quote characters directly? Or newlines? Or variable names (which will be expanded within double quotes)?

The only characters that are illegal in filenames are a slash (/) and a null byte.

In writing scripts you should hold yourself to a much higher standard of robustness than you might at an interactive command line.

At a command line, you can see the command you are about to run, you can confirm it's correct, and you can then run it. In a script, there is no oversight and no confirmation. The script will do what you told it to do, no matter how destructive that may turn out to be.

So the correct approach is actually to use find, as detailed in my other answer. This will handle any filenames correctly and doesn't contain arbitrary code execution vulnerabilities.

Answer 2

Assuming all subdirectories in /path/to/directory follow that naming convention:

cd /path/to/directory
prename -n 's~/\d{4}[a-z]? - ~/~i' */*

prename is the Perl rename (any of the variants will do).

Answer 3

Another answer, using GNU find to handle the renaming. This method is robust regardless of what characters may be in the filename.

If I understand your use case rightly, you want to rename directories that start with the full name of their parent directory. In other words, if your directory is named like so:

/some/path/abcdefghi/abcdefghi - something - else/

You want to rename it like so:

/some/path/abcdefghi/something - else/

Since you specify GNU as a tag on this question, you can use the GNU extensions to the find command and handle this like so:

find . -mindepth 2 -maxdepth 2 -type d -regextype posix-egrep -regex '.*/([^/]+)/\1[^/]+' -exec sh -c 'new="$(sed -r "s:/([^/]+)/\\1 ?-? ?([^/]+)\$:/\\1/\\2:" <<<$1)"; mv "$1" "$new"' find-sh {} \;

Test results:

[vagrant@localhost test]$ mkdir -p SLUG_1/SLUG_{1\ -\ SLUG_{2..4}\ -\ SLUG_5,7\ -\ something}
[vagrant@localhost test]$ find . -type d
.
./SLUG_1
./SLUG_1/SLUG_1 - SLUG_2 - SLUG_5
./SLUG_1/SLUG_1 - SLUG_4 - SLUG_5
./SLUG_1/SLUG_1 - SLUG_3 - SLUG_5
./SLUG_1/SLUG_7 - something
[vagrant@localhost test]$ find . -mindepth 2 -maxdepth 2 -type d -regextype posix-egrep -regex '.*/([^/]+)/\1[^/]+' -exec sh -c 'new="$(sed -r "s:/([^/]+)/\\1 ?-? ?([^/]+)\$:/\\1/\\2:" <<<$1)"; mv "$1" "$new"' find-sh {} \;
[vagrant@localhost test]$ find . -type d
.
./SLUG_1
./SLUG_1/SLUG_3 - SLUG_5
./SLUG_1/SLUG_4 - SLUG_5
./SLUG_1/SLUG_2 - SLUG_5
./SLUG_1/SLUG_7 - something
[vagrant@localhost test]$