Bash script error: "function: not found". Why would this appear?

Question

I'm trying to run a bash script on my Ubuntu machine and it is giving me an error:

function not found

To test, I created the following script which works fine on my laptop but not on my Desktop. Any ideas as to why? My laptop is a mac if that's relevant.

#!/bin/bash  function sayIt {       echo "hello world" }  sayIt 

This returns "hello world" on my laptop, but on my Desktop it returns:

run.sh: 3: function not found hello world run.sh: 5: Syntax error: "}" unexpected

Answer 1

Chances are that on your desktop you are not actually running under bash but rather dash or some other POSIX-compliant shell that does not recognize the function keyword. The function keyword is a bashism, a bash extension. POSIX syntax does not use function and mandates the use of parenthesis.

$ more a.sh #!/bin/sh  function sayIt {       echo "hello world" }  sayIt $ bash a.sh hello world $ dash a.sh a.sh: 3: function: not found hello world a.sh: 5: Syntax error: "}" unexpected 

The POSIX-syntax works in both:

$ more b.sh #!/bin/sh  sayIt () {       echo "hello world" }  sayIt $ bash b.sh hello world $ dash b.sh hello world 

Answer 2

I faced the same problem, I then modified the syntax and it worked for me. Try to remove the keyword function and add brackets () after the function name.

#!/bin/bash  sayIt() {       echo "hello world" }  sayIt