##
##  prop -- Display progress with a running propeller
##  Copyright (c) 1998-2008 Ralf S. Engelschall <rse@engelschall.com>
##
##  This file is part of shtool and free software; you can redistribute
##  it and/or modify it under the terms of the GNU General Public
##  License as published by the Free Software Foundation; either version
##  2 of the License, or (at your option) any later version.
##
##  This file is distributed in the hope that it will be useful,
##  but WITHOUT ANY WARRANTY; without even the implied warranty of
##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
##  General Public License for more details.
##
##  You should have received a copy of the GNU General Public License
##  along with this program; if not, write to the Free Software
##  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
##  USA, or contact Ralf S. Engelschall <rse@engelschall.com>.
##

str_tool="prop"
str_usage="[-p|--prefix <str>]"
arg_spec="0="
opt_spec="p:"
opt_alias="p:prefix"
opt_p=""

. ./sh.common

perl=''
for dir in `echo $PATH | sed -e 's/:/ /g'` .; do
    if [ -f "$dir/perl" ]; then
        perl="$dir/perl"
        break
    fi
done
if [ ".$perl" != . ]; then
    #   Perl is preferred because writing to STDERR in
    #   Perl really writes immediately as one would expect
    $perl -e '
        @p = ("|","/","-","\\");
        $i = 0;
        while (<STDIN>) {
            printf(STDERR "\r%s...%s\b", $ARGV[0], $p[$i++]);
            $i = 0 if ($i > 3);
        }
        printf(STDERR "\r%s    \n", $ARGV[0]);
    ' "$opt_p"
else
    #   But if Perl doesn't exists we use Awk even
    #   some Awk's buffer even the /dev/stderr writing :-(
    awk '
        BEGIN {
            split("|#/#-#\\", p, "#");
            i = 1;
        }
        {
            printf("\r%s%c\b", prefix, p[i++]) > "/dev/stderr";
            if (i > 4) { i = 1; }
        }
        END {
            printf("\r%s    \n", prefix) > "/dev/stderr";
        }
    ' "prefix=$opt_p"
fi

shtool_exit 0

##
##  manual page
##

=pod

=head1 NAME

B<shtool-prop> - B<GNU shtool> propeller processing indication

=head1 SYNOPSIS

B<shtool prop>
[B<-p>|B<--prefix> I<str>]

=head1 DESCRIPTION

This command displays a processing indication though a running
propeller. It is intended to be run at the end of a pipe ("C<|>")
sequence where on C<stdin> logging/processing information found. For
every line on C<stdin> the propeller advances one step clock-wise.

=head1 OPTIONS

The following command line options are available.

=over 4

=item B<-p>, B<--prefix> I<str>

Set a particular prefix I<str> which is displayed in front of the
propeller. The default is no prefix string.

=back

=head1 EXAMPLE

 #   shell script
 configure 2>&1 |\
     tee logfile |\
     shtool prop -p "Configuring sources"

=head1 HISTORY

The B<GNU shtool> B<prop> command was originally written by Ralf S.
Engelschall E<lt>rse@engelschall.comE<gt> in 1998 for B<mod_ssl>. It was
later taken over into B<GNU shtool>.

=head1 SEE ALSO

shtool(1).

=cut