Bash variables with spaces

Question

I'm facing the next problem in MinGW shell under windows. I have in my /etc/profile the expression:

export GIT_SSH="/c/Program Files/TortoiseGit/bin/TortoisePlink.exe"

This doesn't work when I use git fetch on the local repository. But if I do it like this (old DOS way), it works:

export GIT_SSH="/c/Progra~1/TortoiseGit/bin/TortoisePlink.exe"

My question is:

How can I make it work using spaces in the variable?

For testing purpose you can simulate something like this (any example is good):

export VAR="/c/Program Files/TortoiseGit/bin/TortoisePlink.exe"
# and try to execute like this
$VAR

Is there a solution for this (other than the previous mentioned)?

Answer 1

Execute it like this: "$VAR". This is one of the most significant gotchas in shell scripting because strings are always substituted literally and any contained spaces are treated as token delimiters rather than as characters of the string. Think of substituting a variable as a kind of code pasting at runtime.

What really happens when you write $VAR is that the shell tries to execute the binary /c/Program with a first argument Files/TortoiseGit/bin/TortoisePlink.exe.

I learned this the hard way by getting a strange syntax error in a big shell script for a particular input. No other languages I can think of can complain for syntax errors if the runtime input contains special characters - but that is the nature of shell scripting since command interpreters like bash and sh interpret the code line by line.

Whenever you expect a string to contain spaces and you don't want to treat it as separate tokens, enclose it in double quotes.