package Shell;
+use 5.006_001;
+use strict;
+use warnings;
+use File::Spec::Functions;
-use Config;
+our($capture_stderr, $raw, $VERSION, $AUTOLOAD);
+
+$VERSION = '0.72_01';
+$VERSION = eval $VERSION;
+
+sub new { bless \my $foo, shift }
+sub DESTROY { }
sub import {
my $self = shift;
my ($callpack, $callfile, $callline) = caller;
my @EXPORT;
if (@_) {
- @EXPORT = @_;
- }
- else {
- @EXPORT = 'AUTOLOAD';
+ @EXPORT = @_;
+ } else {
+ @EXPORT = 'AUTOLOAD';
}
- foreach $sym (@EXPORT) {
+ foreach my $sym (@EXPORT) {
+ no strict 'refs';
*{"${callpack}::$sym"} = \&{"Shell::$sym"};
}
-};
+}
+
+# NOTE: this is used to enable constant folding in
+# expressions like (OS eq 'MSWin32') and
+# (OS eq 'os2') just like it happened in 0.6 version
+# which used eval "string" to install subs on the fly.
+use constant OS => $^O;
+
+=begin private
-AUTOLOAD {
+=item B<_make_cmd>
+
+ $sub = _make_cmd($cmd);
+ $sub = $shell->_make_cmd($cmd);
+
+Creates a closure which invokes the system command C<$cmd>.
+
+=end private
+
+=cut
+
+sub _make_cmd {
+ shift if ref $_[0] && $_[0]->isa( 'Shell' );
+ my $cmd = shift;
+ my $null = File::Spec::Functions::devnull();
+ $Shell::capture_stderr ||= 0;
+ # closing over $^O, $cmd, and $null
+ return sub {
+ shift if ref $_[0] && $_[0]->isa( 'Shell' );
+ if (@_ < 1) {
+ $Shell::capture_stderr == 1 ? `$cmd 2>&1` :
+ $Shell::capture_stderr == -1 ? `$cmd 2>$null` :
+ `$cmd`;
+ } elsif (OS eq 'os2') {
+ local(*SAVEOUT, *READ, *WRITE);
+
+ open SAVEOUT, '>&STDOUT' or die;
+ pipe READ, WRITE or die;
+ open STDOUT, '>&WRITE' or die;
+ close WRITE;
+
+ my $pid = system(1, $cmd, @_);
+ die "Can't execute $cmd: $!\n" if $pid < 0;
+
+ open STDOUT, '>&SAVEOUT' or die;
+ close SAVEOUT;
+
+ if (wantarray) {
+ my @ret = <READ>;
+ close READ;
+ waitpid $pid, 0;
+ @ret;
+ } else {
+ local($/) = undef;
+ my $ret = <READ>;
+ close READ;
+ waitpid $pid, 0;
+ $ret;
+ }
+ } else {
+ my $a;
+ my @arr = @_;
+ unless( $Shell::raw ){
+ if (OS eq 'MSWin32') {
+ # XXX this special-casing should not be needed
+ # if we do quoting right on Windows. :-(
+ #
+ # First, escape all quotes. Cover the case where we
+ # want to pass along a quote preceded by a backslash
+ # (i.e., C<"param \""" end">).
+ # Ugly, yup? You know, windoze.
+ # Enclose in quotes only the parameters that need it:
+ # try this: c:> dir "/w"
+ # and this: c:> dir /w
+ for (@arr) {
+ s/"/\\"/g;
+ s/\\\\"/\\\\"""/g;
+ $_ = qq["$_"] if /\s/;
+ }
+ } else {
+ for (@arr) {
+ s/(['\\])/\\$1/g;
+ $_ = $_;
+ }
+ }
+ }
+ push @arr, '2>&1' if $Shell::capture_stderr == 1;
+ push @arr, '2>$null' if $Shell::capture_stderr == -1;
+ open(SUBPROC, join(' ', $cmd, @arr, '|'))
+ or die "Can't exec $cmd: $!\n";
+ if (wantarray) {
+ my @ret = <SUBPROC>;
+ close SUBPROC; # XXX Oughta use a destructor.
+ @ret;
+ } else {
+ local($/) = undef;
+ my $ret = <SUBPROC>;
+ close SUBPROC;
+ $ret;
+ }
+ }
+ };
+ }
+
+sub AUTOLOAD {
+ shift if ref $_[0] && $_[0]->isa( 'Shell' );
my $cmd = $AUTOLOAD;
$cmd =~ s/^.*:://;
- eval qq {
- *$AUTOLOAD = sub {
- if (\@_ < 1) {
- `$cmd`;
- }
- elsif (\$Config{'archname'} eq 'os2') {
- local(\*SAVEOUT, \*READ, \*WRITE);
-
- open SAVEOUT, '>&STDOUT' or die;
- pipe READ, WRITE or die;
- open STDOUT, '>&WRITE' or die;
- close WRITE;
-
- my \$pid = system(1, \$cmd, \@_);
- die "Can't execute $cmd: \$!\n" if \$pid < 0;
-
- open STDOUT, '>&SAVEOUT' or die;
- close SAVEOUT;
-
- if (wantarray) {
- my \@ret = <READ>;
- close READ;
- waitpid \$pid, 0;
- \@ret;
- }
- else {
- local(\$/) = undef;
- my \$ret = <READ>;
- close READ;
- waitpid \$pid, 0;
- \$ret;
- }
- }
- else {
- open(SUBPROC, "-|")
- or exec '$cmd', \@_
- or die "Can't exec $cmd: \$!\n";
- if (wantarray) {
- my \@ret = <SUBPROC>;
- close SUBPROC; # XXX Oughta use a destructor.
- \@ret;
- }
- else {
- local(\$/) = undef;
- my \$ret = <SUBPROC>;
- close SUBPROC;
- \$ret;
- }
- }
- }
- };
+ no strict 'refs';
+ *$AUTOLOAD = _make_cmd($cmd);
goto &$AUTOLOAD;
}
1;
+
__END__
=head1 NAME
=head1 SYNOPSIS
-See below.
+ use Shell qw(cat ps cp);
+ $passwd = cat('</etc/passwd');
+ @pslines = ps('-ww'),
+ cp("/etc/passwd", "/tmp/passwd");
+
+ # object oriented
+ my $sh = Shell->new;
+ print $sh->ls('-l');
=head1 DESCRIPTION
+=head2 Caveats
+
+This package is included as a show case, illustrating a few Perl features.
+It shouldn't be used for production programs. Although it does provide a
+simple interface for obtaining the standard output of arbitrary commands,
+there may be better ways of achieving what you need.
+
+Running shell commands while obtaining standard output can be done with the
+C<qx/STRING/> operator, or by calling C<open> with a filename expression that
+ends with C<|>, giving you the option to process one line at a time.
+If you don't need to process standard output at all, you might use C<system>
+(in preference of doing a print with the collected standard output).
+
+Since Shell.pm and all of the aforementioned techniques use your system's
+shell to call some local command, none of them is portable across different
+systems. Note, however, that there are several built in functions and
+library packages providing portable implementations of functions operating
+on files, such as: C<glob>, C<link> and C<unlink>, C<mkdir> and C<rmdir>,
+C<rename>, C<File::Compare>, C<File::Copy>, C<File::Find> etc.
+
+Using Shell.pm while importing C<foo> creates a subroutine C<foo> in the
+namespace of the importing package. Calling C<foo> with arguments C<arg1>,
+C<arg2>,... results in a shell command C<foo arg1 arg2...>, where the
+function name and the arguments are joined with a blank. (See the subsection
+on Escaping magic characters.) Since the result is essentially a command
+line to be passed to the shell, your notion of arguments to the Perl
+function is not necessarily identical to what the shell treats as a
+command line token, to be passed as an individual argument to the program.
+Furthermore, note that this implies that C<foo> is callable by file name
+only, which frequently depends on the setting of the program's environment.
+
+Creating a Shell object gives you the opportunity to call any command
+in the usual OO notation without requiring you to announce it in the
+C<use Shell> statement. Don't assume any additional semantics being
+associated with a Shell object: in no way is it similar to a shell
+process with its environment or current working directory or any
+other setting.
+
+=head2 Escaping Magic Characters
+
+It is, in general, impossible to take care of quoting the shell's
+magic characters. For some obscure reason, however, Shell.pm quotes
+apostrophes (C<'>) and backslashes (C<\>) on UNIX, and spaces and
+quotes (C<">) on Windows.
+
+=head2 Configuration
+
+If you set $Shell::capture_stderr to 1, the module will attempt to
+capture the standard error output of the process as well. This is
+done by adding C<2E<gt>&1> to the command line, so don't try this on
+a system not supporting this redirection.
+
+Setting $Shell::capture_stderr to -1 will send standard error to the
+bit bucket (i.e., the equivalent of adding C<2E<gt>/dev/null> to the
+command line). The same caveat regarding redirection applies.
+
+If you set $Shell::raw to true no quoting whatsoever is done.
+
+=head1 BUGS
+
+Quoting should be off by default.
+
+It isn't possible to call shell built in commands, but it can be
+done by using a workaround, e.g. shell( '-c', 'set' ).
+
+Capturing standard error does not work on some systems (e.g. VMS).
+
+=head1 AUTHOR
+
Date: Thu, 22 Sep 94 16:18:16 -0700
Message-Id: <9409222318.AA17072@scalpel.netlabs.com>
To: perl5-porters@isu.edu
sub ps;
print ps -ww;
- cp("/etc/passwd", "/tmp/passwd");
+ cp("/etc/passwd", "/etc/passwd.orig");
That's maybe too gonzo. It actually exports an AUTOLOAD to the current
package (and uncovered a bug in Beta 3, by the way). Maybe the usual
use Shell qw(echo cat ps cp);
-Larry
+Larry Wall
+Changes by Jenda@Krynicky.cz and Dave Cottle <d.cottle@csc.canterbury.ac.nz>.
-=head1 AUTHOR
+Changes for OO syntax and bug fixes by Casey West <casey@geeknest.com>.
-Larry Wall
+C<$Shell::raw> and pod rewrite by Wolfgang Laun.
+
+Rewritten to use closures rather than C<eval "string"> by Adriano Ferreira.
=cut
https://perl5.git.perl.org / perl5.git / blobdiff