xref: /openbsd-src/gnu/usr.bin/perl/lib/File/Copy.pm (revision e2e5c5d36e4398ba94879f0a31b0307421edcfdb)
1# File/Copy.pm. Written in 1994 by Aaron Sherman <ajs@ajs.com>. This
2# source code has been placed in the public domain by the author.
3# Please be kind and preserve the documentation.
4#
5# Additions copyright 1996 by Charles Bailey.  Permission is granted
6# to distribute the revised code under the same terms as Perl itself.
7
8package File::Copy;
9
10use 5.005_64;
11use strict;
12use Carp;
13our(@ISA, @EXPORT, @EXPORT_OK, $VERSION, $Too_Big, $Syscopy_is_copy);
14sub copy;
15sub syscopy;
16sub cp;
17sub mv;
18
19# Note that this module implements only *part* of the API defined by
20# the File/Copy.pm module of the File-Tools-2.0 package.  However, that
21# package has not yet been updated to work with Perl 5.004, and so it
22# would be a Bad Thing for the CPAN module to grab it and replace this
23# module.  Therefore, we set this module's version higher than 2.0.
24$VERSION = '2.03';
25
26require Exporter;
27@ISA = qw(Exporter);
28@EXPORT = qw(copy move);
29@EXPORT_OK = qw(cp mv);
30
31$Too_Big = 1024 * 1024 * 2;
32
33sub _catname { #  Will be replaced by File::Spec when it arrives
34    my($from, $to) = @_;
35    if (not defined &basename) {
36	require File::Basename;
37	import  File::Basename 'basename';
38    }
39    if ($^O eq 'VMS')  { $to = VMS::Filespec::vmspath($to) . basename($from); }
40    elsif ($^O eq 'MacOS') { $to .= ':' . basename($from); }
41    elsif ($to =~ m|\\|)   { $to .= '\\' . basename($from); }
42    else                   { $to .= '/' . basename($from); }
43}
44
45sub copy {
46    croak("Usage: copy(FROM, TO [, BUFFERSIZE]) ")
47      unless(@_ == 2 || @_ == 3);
48
49    my $from = shift;
50    my $to = shift;
51
52    my $from_a_handle = (ref($from)
53			 ? (ref($from) eq 'GLOB'
54			    || UNIVERSAL::isa($from, 'GLOB')
55                            || UNIVERSAL::isa($from, 'IO::Handle'))
56			 : (ref(\$from) eq 'GLOB'));
57    my $to_a_handle =   (ref($to)
58			 ? (ref($to) eq 'GLOB'
59			    || UNIVERSAL::isa($to, 'GLOB')
60                            || UNIVERSAL::isa($to, 'IO::Handle'))
61			 : (ref(\$to) eq 'GLOB'));
62
63    if (!$from_a_handle && !$to_a_handle && -d $to && ! -d $from) {
64	$to = _catname($from, $to);
65    }
66
67    if (defined &syscopy && !$Syscopy_is_copy
68	&& !$to_a_handle
69	&& !($from_a_handle && $^O eq 'os2' )	# OS/2 cannot handle handles
70	&& !($from_a_handle && $^O eq 'mpeix')	# and neither can MPE/iX.
71	&& !($from_a_handle && $^O eq 'MSWin32')
72       )
73    {
74	return syscopy($from, $to);
75    }
76
77    my $closefrom = 0;
78    my $closeto = 0;
79    my ($size, $status, $r, $buf);
80    local(*FROM, *TO);
81    local($\) = '';
82
83    if ($from_a_handle) {
84	*FROM = *$from{FILEHANDLE};
85    } else {
86	$from = "./$from" if $from =~ /^\s/s;
87	open(FROM, "< $from\0") or goto fail_open1;
88	binmode FROM or die "($!,$^E)";
89	$closefrom = 1;
90    }
91
92    if ($to_a_handle) {
93	*TO = *$to{FILEHANDLE};
94    } else {
95	$to = "./$to" if $to =~ /^\s/s;
96	open(TO,"> $to\0") or goto fail_open2;
97	binmode TO or die "($!,$^E)";
98	$closeto = 1;
99    }
100
101    if (@_) {
102	$size = shift(@_) + 0;
103	croak("Bad buffer size for copy: $size\n") unless ($size > 0);
104    } else {
105	$size = -s FROM;
106	$size = 1024 if ($size < 512);
107	$size = $Too_Big if ($size > $Too_Big);
108    }
109
110    $! = 0;
111    for (;;) {
112	my ($r, $w, $t);
113	defined($r = sysread(FROM, $buf, $size))
114	    or goto fail_inner;
115	last unless $r;
116	for ($w = 0; $w < $r; $w += $t) {
117	    $t = syswrite(TO, $buf, $r - $w, $w)
118		or goto fail_inner;
119	}
120    }
121
122    close(TO) || goto fail_open2 if $closeto;
123    close(FROM) || goto fail_open1 if $closefrom;
124
125    # Use this idiom to avoid uninitialized value warning.
126    return 1;
127
128    # All of these contortions try to preserve error messages...
129  fail_inner:
130    if ($closeto) {
131	$status = $!;
132	$! = 0;
133	close TO;
134	$! = $status unless $!;
135    }
136  fail_open2:
137    if ($closefrom) {
138	$status = $!;
139	$! = 0;
140	close FROM;
141	$! = $status unless $!;
142    }
143  fail_open1:
144    return 0;
145}
146
147sub move {
148    my($from,$to) = @_;
149    my($copied,$fromsz,$tosz1,$tomt1,$tosz2,$tomt2,$sts,$ossts);
150
151    if (-d $to && ! -d $from) {
152	$to = _catname($from, $to);
153    }
154
155    ($tosz1,$tomt1) = (stat($to))[7,9];
156    $fromsz = -s $from;
157    if ($^O eq 'os2' and defined $tosz1 and defined $fromsz) {
158      # will not rename with overwrite
159      unlink $to;
160    }
161    return 1 if rename $from, $to;
162
163    ($sts,$ossts) = ($! + 0, $^E + 0);
164    # Did rename return an error even though it succeeded, because $to
165    # is on a remote NFS file system, and NFS lost the server's ack?
166    return 1 if defined($fromsz) && !-e $from &&           # $from disappeared
167                (($tosz2,$tomt2) = (stat($to))[7,9]) &&    # $to's there
168                ($tosz1 != $tosz2 or $tomt1 != $tomt2) &&  #   and changed
169                $tosz2 == $fromsz;                         # it's all there
170
171    ($tosz1,$tomt1) = (stat($to))[7,9];  # just in case rename did something
172    return 1 if ($copied = copy($from,$to)) && unlink($from);
173
174    ($tosz2,$tomt2) = ((stat($to))[7,9],0,0) if defined $tomt1;
175    unlink($to) if !defined($tomt1) or $tomt1 != $tomt2 or $tosz1 != $tosz2;
176    ($!,$^E) = ($sts,$ossts);
177    return 0;
178}
179
180*cp = \&copy;
181*mv = \&move;
182
183# &syscopy is an XSUB under OS/2
184unless (defined &syscopy) {
185    if ($^O eq 'VMS') {
186	*syscopy = \&rmscopy;
187    } elsif ($^O eq 'mpeix') {
188	*syscopy = sub {
189	    return 0 unless @_ == 2;
190	    # Use the MPE cp program in order to
191	    # preserve MPE file attributes.
192	    return system('/bin/cp', '-f', $_[0], $_[1]) == 0;
193	};
194    } elsif ($^O eq 'MSWin32') {
195	*syscopy = sub {
196	    return 0 unless @_ == 2;
197	    return Win32::CopyFile(@_, 1);
198	};
199    } else {
200	$Syscopy_is_copy = 1;
201	*syscopy = \&copy;
202    }
203}
204
2051;
206
207__END__
208
209=head1 NAME
210
211File::Copy - Copy files or filehandles
212
213=head1 SYNOPSIS
214
215  	use File::Copy;
216
217	copy("file1","file2");
218  	copy("Copy.pm",\*STDOUT);'
219	move("/dev1/fileA","/dev2/fileB");
220
221  	use POSIX;
222	use File::Copy cp;
223
224	$n=FileHandle->new("/dev/null","r");
225	cp($n,"x");'
226
227=head1 DESCRIPTION
228
229The File::Copy module provides two basic functions, C<copy> and
230C<move>, which are useful for getting the contents of a file from
231one place to another.
232
233=over 4
234
235=item *
236
237The C<copy> function takes two
238parameters: a file to copy from and a file to copy to. Either
239argument may be a string, a FileHandle reference or a FileHandle
240glob. Obviously, if the first argument is a filehandle of some
241sort, it will be read from, and if it is a file I<name> it will
242be opened for reading. Likewise, the second argument will be
243written to (and created if need be).
244
245B<Note that passing in
246files as handles instead of names may lead to loss of information
247on some operating systems; it is recommended that you use file
248names whenever possible.>  Files are opened in binary mode where
249applicable.  To get a consistent behaviour when copying from a
250filehandle to a file, use C<binmode> on the filehandle.
251
252An optional third parameter can be used to specify the buffer
253size used for copying. This is the number of bytes from the
254first file, that wil be held in memory at any given time, before
255being written to the second file. The default buffer size depends
256upon the file, but will generally be the whole file (up to 2Mb), or
2571k for filehandles that do not reference files (eg. sockets).
258
259You may use the syntax C<use File::Copy "cp"> to get at the
260"cp" alias for this function. The syntax is I<exactly> the same.
261
262=item *
263
264The C<move> function also takes two parameters: the current name
265and the intended name of the file to be moved.  If the destination
266already exists and is a directory, and the source is not a
267directory, then the source file will be renamed into the directory
268specified by the destination.
269
270If possible, move() will simply rename the file.  Otherwise, it copies
271the file to the new location and deletes the original.  If an error occurs
272during this copy-and-delete process, you may be left with a (possibly partial)
273copy of the file under the destination name.
274
275You may use the "mv" alias for this function in the same way that
276you may use the "cp" alias for C<copy>.
277
278=back
279
280File::Copy also provides the C<syscopy> routine, which copies the
281file specified in the first parameter to the file specified in the
282second parameter, preserving OS-specific attributes and file
283structure.  For Unix systems, this is equivalent to the simple
284C<copy> routine.  For VMS systems, this calls the C<rmscopy>
285routine (see below).  For OS/2 systems, this calls the C<syscopy>
286XSUB directly. For Win32 systems, this calls C<Win32::CopyFile>.
287
288=head2 Special behaviour if C<syscopy> is defined (OS/2, VMS and Win32)
289
290If both arguments to C<copy> are not file handles,
291then C<copy> will perform a "system copy" of
292the input file to a new output file, in order to preserve file
293attributes, indexed file structure, I<etc.>  The buffer size
294parameter is ignored.  If either argument to C<copy> is a
295handle to an opened file, then data is copied using Perl
296operators, and no effort is made to preserve file attributes
297or record structure.
298
299The system copy routine may also be called directly under VMS and OS/2
300as C<File::Copy::syscopy> (or under VMS as C<File::Copy::rmscopy>, which
301is the routine that does the actual work for syscopy).
302
303=over 4
304
305=item rmscopy($from,$to[,$date_flag])
306
307The first and second arguments may be strings, typeglobs, typeglob
308references, or objects inheriting from IO::Handle;
309they are used in all cases to obtain the
310I<filespec> of the input and output files, respectively.  The
311name and type of the input file are used as defaults for the
312output file, if necessary.
313
314A new version of the output file is always created, which
315inherits the structure and RMS attributes of the input file,
316except for owner and protections (and possibly timestamps;
317see below).  All data from the input file is copied to the
318output file; if either of the first two parameters to C<rmscopy>
319is a file handle, its position is unchanged.  (Note that this
320means a file handle pointing to the output file will be
321associated with an old version of that file after C<rmscopy>
322returns, not the newly created version.)
323
324The third parameter is an integer flag, which tells C<rmscopy>
325how to handle timestamps.  If it is E<lt> 0, none of the input file's
326timestamps are propagated to the output file.  If it is E<gt> 0, then
327it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
328timestamps other than the revision date are propagated; if bit 1
329is set, the revision date is propagated.  If the third parameter
330to C<rmscopy> is 0, then it behaves much like the DCL COPY command:
331if the name or type of the output file was explicitly specified,
332then no timestamps are propagated, but if they were taken implicitly
333from the input filespec, then all timestamps other than the
334revision date are propagated.  If this parameter is not supplied,
335it defaults to 0.
336
337Like C<copy>, C<rmscopy> returns 1 on success.  If an error occurs,
338it sets C<$!>, deletes the output file, and returns 0.
339
340=back
341
342=head1 RETURN
343
344All functions return 1 on success, 0 on failure.
345$! will be set if an error was encountered.
346
347=head1 AUTHOR
348
349File::Copy was written by Aaron Sherman I<E<lt>ajs@ajs.comE<gt>> in 1995,
350and updated by Charles Bailey I<E<lt>bailey@newman.upenn.eduE<gt>> in 1996.
351
352=cut
353
354