Bash modifiers in script

Question

If I run the following in a bash shell:

./script /path/to/file.txt
echo !$:t

it outputs file.txt and all is good.

If in my script I have:

echo $1:t

it outputs /path/to/file.txt:t

How can I get it to output file.txt as per the behaviour I see in a shell? Thanks in advance.

Answer 1

Use the parameter expansion syntax:

echo ${1##*/}

Answer 2

In bash you can use the ${1##*/} expansion to get the basename of the file with all leading path components removed:

$ set -- /path/to/file
$ echo "$1"
/path/to/file
$ echo "${1##*/}"
file

You can use this in a script as well:

#!/bin/sh

echo "${1##*/}"

While ${1##*/} will work when Bash is called as /bin/sh, other Bash features require that you use #!/bin/bash at the start of your script. This notation may also not be available in other shells.

A more portable solution is this:

#!/bin/sh

echo `basename "$1"`

Answer 3

Modifier only work on word designators