Check if a function exists before executing it in shell

Question

I want to check if a function exist or not before executing it in the shell script. Does script shell support that? and how to do it?

Accepted Answer

As read in this comment, this should make it:

```
type -t function_name
```

this returns `function` if it is a function.

Test

```
$ type -t f_test
$ 
$ f_test () { echo "hello"; }
$ type -t f_test
function
```

Note that `type` provides good informations:

```
$ type -t ls
alias
$ type -t echo
builtin
```

Solution