Question

Here’s a simple version of my script which displays the failure:

#!/bin/bash
${something:="false"}
${something_else:="blahblah"}
${name:="file.ext"}

echo ${something}
echo ${something_else}
echo ${name}

When I echo the variables, I get the values I put in, but it also emits an error. What am I doing wrong?

Output:

./test.sh: line 3: blahblah: command not found
./test.sh: line 4: file.ext: command not found
false
blahblah
file.ext

The first two lines are being emitted to stderr, while the next three are being output to stdout.

My platform is fedora 15, bash version 4.2.10.

Answer 1

Putting a variable on a line by itself will execute the command stored in the variable. That an assignment is being performed at the same time is incidental.

In short, don’t do that.

echo ${something:="false"}
echo ${something_else:="blahblah"}
echo ${name:="file.ext"}