package File::Tools;
use strict;
use warnings;
use base 'Exporter';
my @all = qw(
basename
catfile
compare
copy
cwd
date
dirname
fileparse
find
mkpath
move
popd
pushd
rm
rmtree
uniq
);
our @EXPORT_OK = @all;
our %EXPORT_TAGS = (
all => \@all,
);
our $VERSION = '0.09';
my @DIRS; # used to implement pushd/popd
sub _not_implemented {
die "Not implemented\n";
}
=head1 NAME
File::Tools - UNIX tools implemented as Perl Modules and made available to other platforms as well
=head1 SYNOPSIS
use File::Tools qw(:all);
my $str = cut {bytes => "3-7"}, "123456789";
=head1 WARNING
This is Alpha version of the module.
Interface of the functions will change and some of the functions might even disappear.
=head1 REASON
Why this module?
=over 4
=item *
When I am writing filesystem related applications I always need to load several
standard modules such as File::Basename, Cwd, File::Copy, File::Path and maybe
others in order to have all the relevant functions.
I'd rather just use one module that will bring all the necessary functions.
=item *
On the other hand when I am in OOP mood I want all these functions to be methods of
a shell-programming-object. (Though probably L<Pipe> will answer this need better)
=item *
There are many useful commands available for the Unix Shell Programmer that usually need
much more coding than the Unix counterpart, specifically most of the Unix commands can work
recoursively on directory structures while in Perl one has to implement these.
There are some additional modules providing this functionality but then we get back again to
the previous issue.
=back
The goal of this module is to make it even easier to write scripts in Perl that
were traditionally easier to write in Shell.
Partially we will provide functions similar to existing UNIX commands
and partially we will provide explanation on how to rewrite various Shell
constructs in Perl.
=head1 DESCRIPTION
#=head2 awk
#
#Not implemented.
#
#=cut
#sub awk {
# _not_implemented();
#}
=head2 basename
Given a path to a file or directory returns the last part of the path.
See L<File::Basename> for details.
=cut
sub basename {
require File::Basename;
File::Basename::basename(@_);
}
=head2 cat
Not implemented.
See L<slurp>
To process all the files on the command line and print them to the screen.
while (my $line = <>) {
print $line;
}
In shell cut is usually used to concatenate two or more files. That can be achived
with the previous code redirecting it to a file using > command line redirector.
=cut
sub cat {
_not_implemented();
}
=head2 catfile
Concatenating parts of a path in a platform independent way. See also L<File::Spec>
=cut
sub catfile {
require File::Spec;
File::Spec->catfile(@_);
}
=head2 cd
Use the built in chdir function.
=cut
=head2 chmod
Use the built in chmod function.
=cut
=head2 chown
For now use the built in chown function.
It accepts only UID and GID values, but it is easy to retreive them:
chown $uid, $gid, @files;
chown getpwnam($user), getgrname($group), @files;
For recursive application use the L<find> function.
find( sub {chown $uid, $gid, $_}, @dirs);
Windows: See chmod above.
=cut
=head2 cmp
See C<compare>
=head2 compare
Compare two files
See L<File::Compare> for details.
=cut
sub compare {
require File::Compare;
File::Compare::compare(@_);
}
=head2 compress
Not implemented.
See some of the external modules
=cut
=head2 copy
Copy one file to another name.
For details see L<File::Copy>
For now this does not provide recourseive copy. Later we will provide that
too using either one of these modules: L<File::NCopy> or L<File::Copy::Recursive>.
=cut
sub copy {
require File::Copy;
File::Copy::copy(@_);
}
=head2 cut
Partially implemented but probably will be removed.
Returns some of the fields of a given string (or strings).
As a UNIX command it can work on every line on STDIN or in a list of files.
When implementing it in Perl the most difficult part is to parse the parameters
in order to account for all the overlapping possibilities which should actually
be considered as user error.
cut -b 1 file
cut -b 3,7 file
cut -b 3-7 file
cut -b -4,7-
order within the parameter string does not matter
The same can be done in Perl for any single range:
substr $str, $start, $length;
=cut
sub cut {
# --bytes
# --characters
# --fields
# --delimiter (in case --fields was used, defaults to TAB)
my ($args, $str) = @_;
if ($args->{bytes}) {
my $chars;
my @ranges = split /,/, $args->{bytes};
my %chars;
foreach my $range (@ranges) {
if ($range =~ /^-/) {
$range = "1$range";
} elsif ($range =~ /-$/) {
$range = $range . length($str)-1;
}
if ($range =~ /-/) {
my ($start, $end) = split /-/, $range;
$chars{$_}=1 for $start..$end;
} else {
$chars{$range} = 1;
}
}
my $ret = "";
foreach my $c (sort {$a <=> $b} keys %chars) {
$ret .= substr($str, $c-1, 1);
}
return $ret;
}
return;
}
=head2 cp
See L<copy> instead.
=cut
=head2 cwd
Returns the current working directory similar to the pwd UNIX command.
See L<Cwd> for details.
=cut
sub cwd {
require Cwd;
Cwd::cwd();
}
=head2 date
Can be used to display time in the same formats the date command would do.
See POSIX::strftime for details.
=cut
sub date {
require POSIX;
POSIX::strftime(@_);
}
=head2 df
Not implemented.
See L<Filesys::DiskSpace>
=cut
sub df {
_not_implemented();
}
=head2 diff
Not implemented.
See L<Text::Diff> for a possible implementation.
=cut
sub diff {
_not_implemented();
}
=head2 dirname
Given a path to a file or a directory this function returns the directory part.
(the whole string excpet the last part)
See L<File::Basename> for details.
=cut
sub dirname {
require File::Basename;
File::Basename::dirname(@_);
}
=head2 dirs
Not implemented.
=cut
=head2 dos2unix
Not implemented.
=cut
=head2 du
Not implemented.
L<Filesys::DiskUsage>
=cut
=head2 echo
Not implemented.
The print function in Perl prints to the screen (STDOUT or STDERR).
If the given string is in double quotes "" the backslash-escaped characters take effect (-e mode).
Within single quotes '', they don't have an effect.
For printing new-line include \n withn the double quotes.
=cut
=head2 ed - editor
Not implemented.
=cut
=head2 expr
Not implemented.
In Perl there is no need to use a special function to evaluate an expression.
=over 4
=item *
match
=item *
substr - built in substr
=item *
index - built in index
=item *
length - built in length
=back
=cut
=head2 file
Not implemented.
=cut
=head2 fileparse
This is not a UNIX command but it is provided by the same standard L<File::Basename>
we already use.
=cut
sub fileparse {
require File::Basename;
File::Basename::fileparse(@_);
}
=head2 find
See L<File::Find> for details.
See also find2perl
TODO: Probably will be replaced by L<File::Find::Rule>
=cut
sub find {
require File::Find;
File::Find::find(@_);
}
=head2 ftp
See L<Net::FTP>
=cut
=head2 move
Move a file from one directory to any other directory with any name.
One can use the built in rename function but it only works on the same filesystem.
See L<File::Copy> for details.
=cut
sub move {
require File::Copy;
File::Copy::move(@_);
}
=head2 getopts
Not implemented.
See L<Getops::Std> and L<Getops::Long> for possible implementations we will use here.
=cut
=head2 grep
Not implemented.
A basic implementation of grep in Perl would be the following code:
my $p = shift;
while (<>) {
print if /$p/
}
but within real code we are going to be more interested doing such operation
on a list of values (possibly file lines) already in memory in an array or
piped in from an external file. For this one can use the grep build in function.
@selected = grep { $_ =~ /REGEX/ } @original;
TODO: See also L<File::Grep>
=cut
=head2 gzip
Not implemented.
=cut
=head2 head
Not implemented.
=cut
=head2 id
Normally the id command shows the current username, userid, group and gid.
In Perl one can access the current ireal UID as $< and the effective UID as $>.
The real GID is $( and the effective GID is $) of the current user.
To get the username and the group name use the getpwuid($uid) and getpwgrid($gid)
functions respectively in scalar context.
=cut
=head2 kill
See built in kill function.
=cut
=head2 less
Not implemented.
This is used in interactive mode only. No need to provide this functionality here.
=cut
=head2 ln
Not implemented.
See the build in L<link> and L<symlink> functions.
=cut
=head2 ls
Not implemented.
See glob and the opendir/readdir pair for listing filenames
use stat and lstat to retreive information needed for the -l
display mode of ls.
=cut
=head2 mail
Sending e-mails.
See L<Mail::Sendmail> and L<Net::SMTP>
=cut
=head2 mkdir
Not implemented.
See the built in mkdir function.
See also L</mkpath>
=cut
=head2 mkpath
Create a directory with all its parent directories.
See L<File::Path> for details.
=cut
sub mkpath {
require File::Path;
File::Path::mkpath(@_);
}
=head2 more
Not implemented.
This is used in interactive mode only. No need to provide this functionality here.
=cut
=head2 mv
See L<move> instead.
=cut
=head2 paste
Not implemented.
=cut
=head2 patch
Not implemented.
=cut
=head2 ping
See L<Net::Ping>
=cut
=head2 popd
Change directory to last place where pushd was called.
=cut
sub popd {
my $dir = pop @DIRS;
if (chdir $dir) {
return cwd();
} else {
return;
}
}
=head2 pushd
Change directory and save the current directory in a stack. See also L<popd>.
=cut
sub pushd {
my ($dir) = @_;
push @DIRS, cwd;
if (chdir $dir) {
return cwd();
} else {
return;
}
}
=head2 printf
Not implemented.
See the build in L<printf> function.
=cut
=head2 ps
Not implemented.
=cut
=head2 pwd
See L<cwd> instead.
=cut
=head2 read
Not implemented.
read x y z
will read in a line from the keyboard (STDIN) and put the first word into x,
the second word in y and the third word in z
In perl one can implement similar behavior by the following code:
my ($x, $y, $z) = split /\s+/, <STDIN>;
=cut
=head2 rm
Not implemented.
For removing files, see the built in L<unlink> function.
For removing directories see the built in L<rmdir> function.
For removing trees (rm -r) see L<rmtree>
See also L<File::Remove>
=cut
sub rm {
_not_implemented();
}
=head2 rmdir
Not implemented.
For removing empty directories use the built in rmdir function.
For removing tree see L<rmtree>
=cut
=head2 rmtree
Removes a whole directory tree. Similar to rm -rf.
See also L<File::Path>
=cut
sub rmtree {
require File::Path;
File::Path::rmtree(@_);
}
=head2 scp
See also L<Net::SCP>
=cut
#=head2 sed
#
#Not implemented.
#
#=cut
#sub sed {
# _not_implemented();
#}
=head2 slurp
=cut
sub slurp {
my $content = "";
foreach my $filename (@_) {
if (open my $fh, "<", $filename) {
local $/ = undef;
$content .= <$fh>;
} else {
warn "Could not open '$filename'\n";
}
}
return $content;
}
=head2 snmp
L<Net::SNMP>
=cut
=head2 ssh
L<Net::SSH>
=cut
=head2 shift
Not implemented.
=cut
=head2 sort
Not implemented.
See the built in sort function.
=cut
=head2 tail
Not implemented.
Return the last n lines of a file, n defaults to 10
=cut
sub tail {
_not_implemented();
}
=head2 tar
Not implemented.
See L<Archive::Tar>
=cut
=head2 telnet
L<Net::Telnet>
=cut
=head2 time
See also L<Benchmark>
=cut
=head2 touch
Not implemented.
=head2 tr
Not implemented.
See the built in L<tr> function.
=head2 umask
Not implemented.
=cut
=head2 uniq
The uniq unix command eliminates duplicate values following each other
but does not enforce uniqueness through the whole input.
For examle for the following list of input values: a a a b a a a
ths UNIX uniq would return a b a
For completeness we also provide uniqunix that behaves just like the UNIX command.
See also L<Array::Unique>
=cut
sub uniq {
my (@uniq, %seen);
for (@_) {
push @uniq, $_ if not $seen{$_}++;
}
return @uniq;
}
=head2 uniqunix
Similar to the UNIX uniq command.
=cut
sub uniqunix {
my (@uniq, $last);
for (@_) {
next if defined $last and $last eq $_;
$last = $_;
push @uniq, $last;
}
return @uniq;
}
=head2 unix2dos
Not implemented.
=head2 wc
Not implemented.
=head2 who
Not implemented.
=head2 who am i
Not implemented.
=head2 zip
Not implemented.
=head2 redirections and pipe
<
>
<
|
Ctr-Z, & fg, bg
set %ENV
=head2 Arguments
$#, $*, $1, $2, ...
$$ - is also available in Perl as $$
=head2 Other
$? error code of last command
if test ...
string operators
=head1 TODO
File::Basename::fileparse_set_fstype
File::Compare::compare_text
File::Compare::cmp
File::Copy::syscopy
File::Find
File::Spec
File::Temp
=head1 AUTHOR
Gabor Szabo <gabor@szabgab.com>
=head1 Copyright
Copyright 2006-2012 by Gabor Szabo <gabor@szabgab.com>.
=head1 LICENSE
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
See L<http://www.perl.com/perl/misc/Artistic.html>
=head1 SEE ALSO
Tim Maher has a book called Miniperl http://books.perl.org/book/240 that might be very useful.
I have not seen it yet, but according to what I know about it it should be a good one.
L<http://perllinux.sourceforge.net/>
The UNIX Reconstruction Project, L<http://search.cpan.org/dist/ppt/>
L<http://perl5maven.com/the-most-important-file-system-tools>
L<Pipe>
Related Discussions:
L<http://www.perlmonks.org/?node_id=541826>
=cut
1;