sysexits.h codes? (was: Re: [RFC][PATCH] `newuser` prompt theme)

[Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>]

> >> @@ -0,0 +1,197 @@
> >> +readonly -ga sysexits=(
> >> +    USAGE
> > ⋮
> >> +    CONFIG
> > 
> > Two interrelated scripts on zsh.org hardcode these constants too.
> > I wonder if we should provide these constants in a standard autoloaded
> > function or preset variable.
> 
> A preset variable would be great. In C code, you can get the names and values from `sysexits.h`, which is available in both GNU and BSD.

An associative array mapping symbolic names to integers?  Just those
available on the target system, or?

> >> +  emulate -L zsh
> >> +
> >> +  psvar[1]=
> >> +  case $exitstatus in
> >> +    <128-> )
> >> +      psvar[1]="SIG$signals[exitstatus-127] "
> >> +      ;|
> >> +    <64-78> )
> >> +      psvar[1]="EX_$sysexits[exitstatus-63] "
> > 
> > Nice, I might adopt this.  Or, come to think of it, I might teach
> > PRINT_EXIT_VALUE to do this ☺
> 
> It would be great if, besides printing the name, it could also add a
> short description of what the exit code actually means. Something like
> “SIGPIPE (140): write on a pipe with no reader”.

There's precedent to work with:

    % =pwd | true 
    zsh: broken pipe  =pwd

I suppose the default should be about this level of verbosity.

Other degrees of verbosity could be considered.