Doom-Style Status Bar

[Symuc]

Category:

Fun Stuff

Description:

Reminiscent of the status bar that showed the progress of the startup of the classic game "Doom", this code will print a status bar of variable width with an optional header and/or footer.

 ####################################
## FUNCTION: StatusBar ###############
##################################################
##                                              ##
##   Generates a statusbar that is of variable  ##
## width, and is very adaptable, optionally     ##
## displaying the percentage as well.           ##
##                                              ##
## ARGS:                                        ##
##      0) The text preceeding the bar          ##
##      1) The current value                    ##
##      2) The maximum value                    ##
##      3) The size of the bar (in characters)  ##
##      4) Display the percentage?              ##
##      5) The text following the bar           ##
## Returns:                                     ##
##      NULL                                    ##
##                                              ##
##################################################

sub StatusBar {
  my $level;
  my $numdots;
  my $numblanks;

  my $pre=$_[0];
  my $cur=int($_[1]);
  my $max=int($_[2]);
  my $size=int($_[3]);
  my $disp=$_[4];
  my $i;
  my $post=$_[5];

  $level = $cur/$max;
  
  $numdots = int($level * $size);

  $numblanks = $size - $numdots;

  print $pre . "\t";
  print " [";
  for($i = 0; $i < $numdots; $i++) {
    print ".";
  }
  for($i = 0; $i < $numblanks; $i++) {
    print " ";
  }
  print "]";
  if($disp ne "") {
    printf(" ($cur/$max, %3.2f%%)", (int($level*10000)/100));
  }
  print " $post\r";
}

Edited 2002-01-16 to fix html entities dvergin

[particle]

i tested your code, as formatted by simon.proctor, and decided to modify it to accept a hash as input. i added some minor error checking, and modified your print statements a bit.

here's the code in a full script with a few test runs. below is output, and an explanation of what i did.

#!/usr/local/bin/perl -w
use strict;
$|=1;

sub StatusBar {
    my %args = @_;

    # test for must-have values (cur, max, size)
    unless( defined($args{cur}) ) { die("cur not defined"); }
    unless( defined($args{max}) ) { die("max not defined"); }
    if( defined($args{size}) ) {
        $args{size} = int( $args{size} )
    } else {
        die("size not defined");
    }

    # make sure cur <= max
    unless( $args{cur} <= $args{max} ) { die("cur greater than max"); 
+}

    # compute percentage level ( cur / max )
    my $level = $args{cur} / $args{max};

    # compute number of dots to display ( level * size ), return integ
+er part
    # WARNING!!! int() truncates a number, does not round
    my $numdots = int( $level * $args{size} );

    # print status bar
    defined($args{pre}) && print "$args{pre}\t";
    print "[", 
        "." x $numdots,
        " " x ( $args{size} - $numdots ), 
        "]";
    if($args{disp}) {
        $args{disp} && printf(" (%3.2f%%)", ($level*100));
    }
    defined($args{post}) && print " $args{post}\n";
}

# create hash of standard arguments
my %standard_args = (
    pre  => "begin",
    max  => 100,
    size => 10,
    disp => 1,
    post => "end",
);

# test 1, standard call
StatusBar(
    pre  => "begin",
    cur  => 79,
    max  => 100,
    size => 10,
    disp => 1,
    post => "end",
);

# test 2, use %standard_args, override max, add cur
StatusBar(
    %standard_args,
    cur  => 72.5,
    max  => 91,
);

# test 3, standard call with different values
StatusBar(
    pre  => "begin",
    cur  => 41,
    max  => 90,
    size => 15,
    disp => 0,
    post => "end",
);

# test 4, standard call
StatusBar(
    pre  => "begin",
    cur  => 7,
    max  => 90,
    size => 14,
    disp => 1,
    post => "end",
);

# # uncomment these to test errors
# test 5, cur > max
# StatusBar(
#     cur  => 20,
#     max  => 10,
#     size => 11,
# );
# 
# test 6, cur not passed
# StatusBar(
#     max  => 100,
#     size => 10,
#     disp => 1,
# );

here's the output:

begin   [.......   ] (79.00%) end
begin   [.......   ] (79.67%) end
begin   [......        ] (45.56%) end
begin   [.             ] (7.78%) end

i used a hash for input for a few reasons:
1> it's more readable, therefore, more supportable. hash key/value pairs make the information passed to the subroutine call easier to understand.
2> it's more flexible. you can create a hash of standard arguments, and add to or overwrite the standard values as they're passed to the subroutine.
3> it's more perlish.

i added a bit of error checking, to give you a general idea, but you might want to do more. bounds checking, verifying your input are valid numbers, etc.

i modified the print statement a bit, by using a little perlish trick, print "." x $numdots;.

your idea was a good one, and keep working on your code. i'll probably find use for this in a few of my applications; my users are always looking for more status information.

~Particle

[simon.proctor]

I haven't tested it but your code needed reworking so that the downloaded version would compile.

Update: I wrapped it in a test script for you :). I also added flushing and a sleep to simulate something running slowly (which we were tracking).

#! d:/perl/bin/perl -w

use strict;
$|++;

my $min = 1;
my $max = 100;

while($min != $max)
{
        sleep(1);
    StatusBar('before',$min,$max,25,'y','after');
    $min++;
}

sub StatusBar {
  my $level;
  my $numdots;
  my $numblanks;

  my $pre=$_[0];
  my $cur=int($_[1]);
  my $max=int($_[2]);
  my $size=int($_[3]);
  my $disp="$_[4]";
  my $i;
  my $post=$_[5];

  $level = $cur/$max;
  
  $numdots = int($level * $size);

  $numblanks = $size - $numdots;

  print $pre . "\t";
  print " [";
  for($i = 0; $i < $numdots; $i++) {
    print ".";
  }
  for($i = 0; $i < $numblanks; $i++) {
    print " ";
  }
  print "]";
  if($disp ne "") {
    printf(" ($cur/$max, %3.2f%%)", (int($level*10000)/100));
  }
  print " $post\r";
}


Simon

You're only jealous cos the voices are talking to me