Error 'Syntax error: "(" unexpected' when declaring arrays in bash

Question

Same problem as this OP, but must be a seperate cause.

The following script:

#!/bin/sh
arr=("cat" "dog" "bird")

Works interactively (debian) but fails when called by crontab with:

/bin/sh: 2: /path/zero_check.sh: Syntax error: "(" unexpected

I've tried with #!/bin/bash shebang, and declaring array with declare -a arr=("cat" "dog" "bird"), to no effect.

Any idea why?

Answer 1

The problem here is that you are using this shebang:

#!/bin/sh

Whereas arrays are something Bash specific that shell does not allow.

So to make it work, change the shebang of your script to Bash:

#!/bin/bash

Answer 2

Specify your interpreter explicitly in the crontab entry. Use

bash /path/zero_check.sh

rather than

/path/zero_check.sh