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✏️ Editing: runsh

#!/usr/bin/perl -w

## Demonstration of chatting with a bash shell.

use strict;

use IPC::Run qw( start pump finish timeout );

my ( $in, $out, $err );

my $h = start(
    [qw(sh -login -i )], \$in, \$out, \$err,
    debug => 0,
    timeout(5),
);

## The first thing we do is to convert the user's prompt.  Normally, we would
## do a '' as the first command in the for () loop so we could detect errors
## that bash might emit on startup.  In this case, we need to do this
## initialization first so that we have a prompt to look for so we know that
## it's ready to accept input.  This is all because the startup scripts
## that bash runs set PS1, and we can't have that.
$in = "PS1='<PROMPT> '\n";

## bash prompts on stderr.  Consume everything before the first
## <PROMPT> (which is the second prompt bash issues).
pump $h until $err =~ s/.*(?=^<PROMPT> (?!\n)\Z)//ms;

for (qw( ls ps fOoBaR pwd )) {
    $in  = $_ . "\n";
    $out = '';
    pump $h until $err =~ s/\A(<PROMPT> .*)(?=^<PROMPT> (?!\n)\Z)//ms;
    print map { "sh err: $_\n" } split( /\n/m, $1 );
    print map { "sh: $_\n" } split( /\n/m, $out );
}

finish $h ;

MR SKB