[CentOS] bash - safely pass untrusted strings?

Tue Feb 26 23:13:12 UTC 2008
Les Mikesell <lesmikesell at gmail.com>

Garrick Staples wrote:
> On Tue, Feb 26, 2008 at 04:33:30PM -0600, Les Mikesell alleged:
>> Does anyone have a quick reference to the order of operations as the 
>> shell parses a command line (variable parsing,i/o redirection, wildcard 
>> and variable expansion, splitting on IFS, quote removal, command 
>> substitution etc.)?  That's really the first thing you need to know 
>> about the shell and if there is a simple description it must be buried 
>> in the middle of some obscure manual.
> 
> This is from the "EXPANSION" section of the bash manpage:
> 
>        The  order  of  expansions  is:  brace expansion, tilde expansion, parameter, variable and arithmetic
>        expansion and command substitution (done in a left-to-right fashion), word  splitting,  and  pathname
>        expansion.

That's one step in the bigger picture.  I want the one that includes 
variable assignment, i/o redirection, quote removal, and a few other 
operations.  I think I knew that a few decades ago, but now I don't even 
know where to look it up.

-- 
    Les Mikesell
     lesmikesell at gmail.com