Whitespace treatment in OS X vs Linux in Bash

Question

I am trying to run a very simple script on a few different platforms:

#!/bin/bash
STRING="this is a test"
echo $STRING

, and I cannot tell why on Mavericks and Yosemite I get the output:

./starter.sh line 2: is": command not found

while an online Bash terminal simulator (sorry, I don't have any Linux setup handy, so I am using: this) runs the code as expected. According to Apple's own primer docs this should work. IOW, double-quotes are simply ignored.

A few points:

• there are no spaces in-between variable name, equals operator and assigned value;
• escaping spaces is not a valid answer in my case, as the end goal is to make some more complicated scripts...but obviously I must "graduate" this small step first.

Answer 1

The error message isn't quite right, but it looks a lot like what you'd get if the script had fancy (or "smart") double-quotes instead of plain (ASCII) double-quotes. The shell doesn't understand the fancy quotes, so they'll make the script behave in very weird ways. Try printing out your script with:

LC_ALL=c cat -vet starter.sh

This will show any weird (non-plain-ASCII or nonprinting) characters in the file. If it prints something like:

#!/bin/bash$
STRING=?M-^@M-^\this is a test?M-^@M-^]$
echo $STRING$

... the "?M-^@M-^\" and "?M-^@M-^]" bits are fancy quotes in UTF-8 encoding. On the other hand, if the file's lines end with "^M$" instead of just "$", then Sleafar is right and you've got a DOS/Windows formatted file.

Answer 2

Check what is used as the "end of line" in your file. Different systems use different control characters:

• Linux: LF
• Windows: CR+LF
• Mac: CR

You can't use the same script on all systems without converting it.