How to split a string in shell and get the last field

Question

Suppose I have the string 1:2:3:4:5 and I want to get its last field (5 in this case). How do I do that using Bash? I tried cut, but I

Answer 1

$ echo "a b c d e" | tr ' ' '\n' | tail -1
e

Simply translate the delimiter into a newline and choose the last entry with tail -1.

Answer 2

echo "a:b:c:d:e"|xargs -d : -n1|tail -1

First use xargs split it using ":",-n1 means every line only have one part.Then,pring the last part.

Answer 3

Using sed:

$ echo '1:2:3:4:5' | sed 's/.*://' # => 5

$ echo '' | sed 's/.*://' # => (empty)

$ echo ':' | sed 's/.*://' # => (empty)
$ echo ':b' | sed 's/.*://' # => b
$ echo '::c' | sed 's/.*://' # => c

$ echo 'a' | sed 's/.*://' # => a
$ echo 'a:' | sed 's/.*://' # => (empty)
$ echo 'a:b' | sed 's/.*://' # => b
$ echo 'a::c' | sed 's/.*://' # => c

Answer 4

If your last field is a single character, you could do this:

a="1:2:3:4:5"

echo ${a: -1}
echo ${a:(-1)}

Check string manipulation in bash.

Answer 5

There are many good answers here, but still I want to share this one using basename :

 basename $(echo "a:b:c:d:e" | tr ':' '/')

However it will fail if there are already some '/' in your string. If slash / is your delimiter then you just have to (and should) use basename.

It's not the best answer but it just shows how you can be creative using bash commands.

Answer 6

For those that comfortable with Python, https://github.com/Russell91/pythonpy is a nice choice to solve this problem.

$ echo "a:b:c:d:e" | py -x 'x.split(":")[-1]'

From the pythonpy help: -x treat each row of stdin as x.

With that tool, it is easy to write python code that gets applied to the input.