Re: convolutions

[Ray Andrews <rayandrews@eastlink.ca>]

On 11/06/2015 10:38 PM, Mikael Magnusson wrote:
> No, because 'expanding into "\e"' means nothing useful, did you mean a
> literal backslash followed by an e, or a literal escape?

It's not arguable sir.  If you found it vague, then you found it vague, 
but to me:

      " \e[31;1m "

... is very obviously a color code which I hold in my variable " ${red} 
" and I want to expand it inside a file.

> If you store the string in a parameter and echo that parameter, the 
> color variables also don't expand.
>> So you have a file with "${red}" in it, and you want to read in the
>> file, and substitute the value of any parameter references.

Exactly.
>> Moreover,
>> these parameters are not defined in the file, but are set in the shell
>> environment and you happen to know that they are string
>> representations of color escape sequences, and you want to expand
>> these as well.

Of course. Who but me knows what's in my environment variables?
>> If your file has a semicolon in it somewhere, then your command will
>> run arbitrary code. Bart's example doesn't have that exact problem,
>> but will still execute code if there are things like $(command) in the
>> file.
>>
Yes, I know how dangerous eval is, that's why I'm asking for a better 
idea--some way of expanding parameters  inside a file.  Not just color 
variables really, any variables.