linux bash, camel case string to separate by dash

Question

Is there a way to convert something like this:

MyDirectoryFileLine

to

my-directory-file-line

I found some ways to convert all letters to uppercase or lowercase, but not in that way; any ideas?

Answer 1

You can use s/\([A-Z]\)/-\L\1/g to find an upper case letter and replace it with a dash and it's lower case. However, this gives you a dash at the beginning of the line, so you need another sed expression to handle that.

This should work:

sed --expression 's/\([A-Z]\)/-\L\1/g' \
    --expression 's/^-//'              \
    <<< "MyDirectoryFileLine"

Answer 2

I propose to use sed to do that:

NEW=$(echo MyDirectoryFileLine        \
     | sed 's/\(.\)\([A-Z]\)/\1-\2/g' \
     | tr '[:upper:]' '[:lower:]')

UPD I forget to convert to lower case, updated code

Answer 3

echo MyDirectoryFileLine | perl -ne 'print lc(join("-", split(/(?=[A-Z])/)))'

prints my-directory-file-line

Answer 4

Slight variation on @bilalq's answer that covers some more possible edge cases:

echo "MyDirectoryMVPFileLine"                          \
| sed 's/\([^A-Z]\)\([A-Z0-9]\)/\1-\2/g'               \
| sed 's/\([A-Z0-9]\)\([A-Z0-9]\)\([^A-Z]\)/\1-\2\3/g' \
| tr '[:upper:]' '[:lower:]'

output is still:

my-directory-mvp-file-line

but also:

WhatADeal -> what-a-deal
TheMVP -> the-mvp
DoSomeABTesting -> do-some-ab-testing
The3rdThing -> the-3rd-thing
The3Things -> the-3-things
ThingNumber3 -> thing-number-3