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|
#!/usr/bin/perl
use strict;
use warnings;
use English;
################################################################################
# Begin main execution
################################################################################
my @dirs = splice(@ARGV, 0);
my %dir_contents_table;
my $max_length = 0;
my $output_format;
# The original problem specified three directories but
# this system will work with two or more
die("E: must provide at least two directories\n")
if(scalar(@dirs) < 2);
# Alphabetize directories
@dirs = sort(@dirs);
# Loop over the specified directories
foreach my $dir (@dirs){
my $dirhandle;
my $length = length($dir);
# Update the max file/dir name length seen
$max_length = $length
if($length > $max_length);
opendir($dirhandle, $dir)
or die("E: Could not open directory $dir: $!");
# Loop over the contents of the directory
while(my $file = readdir($dirhandle)){
# Skip "." and ".."
next if($file =~ m/^\.{1,2}$/);
# If the file is a directory, append a slash
$file .= "/"
if( -d $dir."/".$file);
# Update the max file/dir name length seen
$length = length($file);
$max_length = $length
if($length > $max_length);
# Note that we saw a file with this name in this dir
$dir_contents_table{$file}{$dir} = 1;
}
closedir($dirhandle)
or die("E: Could not close directory $dir: $!");
}
# Set up an output format befitting the size and amount
# of data we've examined
$output_format = join(
" | ",
map("%-" . $max_length . "s", 0 .. $#dirs)
) . "\n";
# Print out a header with dir names
print("\n");
printf($output_format, @dirs);
printf($output_format, map("-" x $max_length, 0 .. $#dirs));
# Look up and output the filenames that were not found
# in every specified directory
foreach my $file (sort(keys(%dir_contents_table))){
if(scalar(keys(%{$dir_contents_table{$file}})) != scalar(@dirs)){
# There was at least one dir that did not have this file
printf(
$output_format,
# If $dir_contents_table{$file}{$_} is true, that file
# had been seen in the directory named in $_
map($dir_contents_table{$file}{$_} ? $file : "", @dirs)
);
}
}
print("\n");
exit(0);
################################################################################
# End main execution; subroutines follow
################################################################################
|
