Operations On Directories
Creating a Directory:
<![CDATA[
#!/usr/bin/perl -w
#mkdir syntax
#mkdir (dirname, permissions)
#dirname can be a full path
mkdir ("TESTDIR", 0777);
Removing a directory:
#!/usr/bin/perl -w
#rmdir syntax
#rmdir (dirname)
rmdir ("TESTDIR");
]]>
Printing contents of a directory:
<![CDATA[
#!/usr/bin/perl -w
opendir(HOMEDIR, "../PERL") || die ("NO DIRECTORY WITH THAT NAME");
@files = readdir(HOMEDIR);
closedir(HOMEDIR);
foreach $file (sort @files){
print ("$file\n");
}
]]>
Listing Contents of a Folder
<![CDATA[
#!/usr/bin/perl -w
use strict;
use BeginPerlBioinfo;
my @files = ();
my $folder = 'pdb';
unless(opendir(FOLDER, $folder)){
print "Cannot open folder $folder!\n";
exit;
}
@files = readdir(FOLDER);
closedir(FOLDER);
print join("\n", @files), "\n";
exit;
]]>
List folders and subfolders
<![CDATA[
#!/usr/bin/perl -w
use strict;
use BeginPerlBioinfo;
my @files = ();
my $folder = 'pdb';
unless(opendir(FOLDER, $folder)){
print "Cannot open folder $folder!\n";
exit;
}
@files = grep(!/^\.\.?/, readdir(FOLDER));
closedir(FOLDER);
foreach my $file(@files){
if(-f "$folder/$file"){
print "$folder/$file\n";
}elsif(-d "$folder/$file"){
my $folder = "$folder/$file";
unless(opendir(FOLDER, "$folder")){
print "Cannot open folder $folder!\n";
exit;
}
my @files = grep (!/^\.\.?$/, readdir(FOLDER));
closedir(FOLDER);
foreach my $file (@files) {
print "$folder/$file\n"
}
}
}
exit;
]]>
Recursive subroutine to list filesystem
<![CDATA[
#!/usr/bin/perl -w
use strict;
list_recursively('pdb');
exit;
sub list_recursively{
my($directory) = @_;
my @files = ();
unless(opendir(DIRECTORY, $directory)){
print "Cannot open directory $directory!\n";
exit;
}
@files = grep(!/^\.\.?$/, readdir(DIRECTORY));
closedir(DIRECTORY);
foreach my $file (@files) {
if(-f "$directory/$file"){
print "$directory/$file\n";
}elsif(-d "$directory/$file"){
list_recursively("$directory/$file");
}
}
}
]]>
ASSIGNMENT: