[CentOS] C5 BASH IF

Les Mikesell lesmikesell at gmail.com
Sat Feb 14 18:03:48 UTC 2015


On Sat, Feb 14, 2015 at 11:36 AM, J Martin Rushton
<martinrushton56 at btinternet.com> wrote:
> <snip>
>> To understand it completely you need to know the order of
>> operations as the shell makes multiple passes over the line,
>> parsing, processing metacharacters, and expanding variables.   And
>> I don't know where to find a concise description of that any more.
>
> man bash, about 900 lines down under "EXPANSION".

But it is not 'just' expansions.  You need to know the full order of
operations with all the steps - word splitting, quote removal,  i/o
redirection, groupings, etc., some of which is repeated over the line
after some of the other steps happen.   I think I saw this in an
understandable form for the bourne shell back in the 1980's but can't
remember it well enough to describe and all the bash docs I've seen
are way too convoluted to just see the order of operations as a simple
set of steps - that you need to know before any of the rest will make
sense.

-- 
   Les Mikesell
      lesmikesell at gmail.com



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