tty-eof

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh

: ${PERL=perl}

case "$PERL" in
  *'missing perl')
  echo 1>&2 "$0: configure didn't find a usable version of Perl, so can't run thi
s test"
  exit 77
  ;;
esac

ARGV_0=$0
export ARGV_0

exec $PERL -w -- - <<\EOF

# Ensure that cat exits upon a single EOF (^D) from a tty.
# Do the same for all programs that can read stdin,
# requiring no arguments and that write to standard output.
use strict;

(my $ME = $ENV{ARGV_0}) =~ s|.*/||;

# Some older versions of Expect.pm (e.g. 1.07) lack the log_user method,
# so check for that, too.
eval { require Expect; Expect->require_version('1.11') };
$@ and (warn "$ME: this script requires Perl's Expect package >=1.11\n"),
  exit 77;

{
  my $fail = 0;
  foreach my $cmd (qw( cat cksum dd expand fmt fold head md5sum nl od
		       paste pr ptx sha1sum sort sum tac tee tail tsort
		       unexpand uniq wc ))
    {
      my $exp = new Expect;
      $exp->log_user(0);
      $exp->spawn($cmd)
	or (warn "$ME: cannot run `$cmd': $!\n"), $fail=1, next;
      $exp->send("foo\n");
      $exp->send('');  # FIXME: it'd be better not to hard-code ^D here
      $exp->expect (0, '-re', "^foo\\r?\$");
      my $found = $exp->expect (1, '-re', "^.+\$");
      # $found and warn "F: $found: " . $exp->exp_match () . "\n";
      $exp->expect(1, 'eof');
      defined $found
	or (warn "$ME: $cmd didn't produce expected output\n"),
	  $fail=1, next;
      defined defined $exp->exitstatus
	or (warn "$ME: $cmd didn't exit after ^D from standard input\n"),
	  $fail=1, next;
      my $s = $exp->exitstatus;
      $s == 0
	or (warn "$ME: $cmd exited with status $s (expected 0)\n"),
	  $fail=1;
      $exp->hard_close();
    }

  exit $fail
}
EOF