Sometimes when you run a bash/shell command and you get errors, it might be that your shell is using dash.

We have a script to check and install npm modules:

if [[ ${NPM_INSTALL} == 'YES' ]]
then
    echo "$(tput setaf 4)Doing NPM Install...$(tput sgr0)"
fi

then when we run the script we get

sh test.sh -npm
test.sh: 12: test.sh: [[: not found

To see what shell your server is using run the following

$ ls -l /bin/sh
lrwxrwxrwx 1 root root 4 ago 15  2012 /bin/sh > dash

As you can see, /bin/sh is a link to "dash" (not bash), and [[ is bash syntactic sugarness. So I just replaced the link to /bin/bash. Careful using rm like this in your system!

All you need to do is remove the symbolic link to dash and replace it with bash/sh

$ sudo rm /bin/sh
$ sudo ln -s /bin/bash /bin/sh

Now when i run the command it goes into the if statement

sh test.sh --npm
Doing NPM Install...