Bash: "command not found" on simple variable assignment
You can add colon:
: ${something:="false"}: ${something_else:="blahblah"}: ${name:="file.ext"}The trick with a ":" (no-operation command) is that, nothing gets executated, but parameters gets expanded. Personally I don't like this syntax, because for people not knowing this trick the code is difficult to understand.
You can use this as an alternative:
something=${something:-"default value"}or longer, more portable (but IMHO more readable):
[ "$something" ] || something="default value"
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"}
It's simply
variable_name=valueIf you use $(variable_name:=value} bash substitutes the variable_name if it is set otherwise it uses the default you specified.