The shell is fundamentally an interpreter; stuff written in shell can't
possibly be as fast as the code that is interpreting it. In general, native
tools are going to be more efficient.

I mean, if you had to write code in your awk program to do the parsing and
splitting that it does automatically, that would be slow, too. But you
don't, because it's it's already written for you inside the awk binary, and
in compiled C rather than interpreted awk.

In college I wrote a complete email-based helpdesk/workflow system for my
team of sysadmins, and I prided myself on doing so entirely in pure ksh,
like the Rand MH reimplementation in the back of Korn's book. I definitely
went too far in the direction of avoiding external tools, and have since
corrected.

As I see it, the shell is best utilized as commander and coordinator rather
than actually doing the hands-on nitty-gritty work; that's better delegated
to more efficient (and usually more specialized) tools. The shell can
absolutely do it, but it won't be the best application of the available
resources.

_
Mark J. Reed <markjreed@gmail.com>


On Wed, May 22, 2024 at 20:30 Ray Andrews <rayandrews@eastlink.ca> wrote:

>
>
> On 2024-05-22 17:04, Lawrence Velázquez wrote:
>
> Yes, it's quite common -- borderline universal -- to start with sed
> and pick up awk later.
>
> Good to know.  Sometimes I think I get everything wrong.
>
> You take this way too far, in my opinion.  Compared to appropriate
> external tools, zsh-heavy solutions often perform poorly and are
> more difficult to understand and maintain.  (Compare your original
> code to the awk solutions Mark and Roman offered.)  Most of your
> code would improve if you (judiciously) used more external utilities
> and less zsh.
>
> It seems 'obvious' that internal code would be faster, but I know from
> Roman's various tests over the years that it ain't necessarily so.
> Besides, at the concept level, shells are intended as glue between system
> commands and all their internal abilities are addons.  I suppose when,  as
> you say, one replaces a multi line internal construction with a single line
> construction that calls an external prog. the mere fact of many lines to
> interpret has a penalty right there that you'd not notice in a compiled
> program.
>
>
>