Determine command type (alias, keyword, function, builtin, or file)

type -t $1
Prints a string indicating whether a command is an alias, keyword, function, builtin, or file. I have used this in my BASH scripts to allow an external parameter to define which function to run, and ensure that it is a valid function that can indeed be run.
Sample Output
#Determine if a command is an available function
#Useful in BASH scripts
#Usage: is_fun test_function
#Returns: string: yes | no
is_fun() { if [ "$(type -t $1)" == "function" ]; then echo "yes"; else echo "no"; fi }

1
By: bbbco
2012-01-10 21:57:29

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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