xref: /openbsd-src/gnu/usr.bin/perl/lib/File/Copy.pm (revision 62a742911104f98b9185b2c6b6007d9b1c36396c)
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 strict;
11use Carp;
12use vars qw(@ISA @EXPORT @EXPORT_OK $VERSION $Too_Big
13	    &copy &syscopy &cp &mv);
14
15# Note that this module implements only *part* of the API defined by
16# the File/Copy.pm module of the File-Tools-2.0 package.  However, that
17# package has not yet been updated to work with Perl 5.004, and so it
18# would be a Bad Thing for the CPAN module to grab it and replace this
19# module.  Therefore, we set this module's version higher than 2.0.
20$VERSION = '2.02';
21
22require Exporter;
23@ISA = qw(Exporter);
24@EXPORT = qw(copy move);
25@EXPORT_OK = qw(cp mv);
26
27$Too_Big = 1024 * 1024 * 2;
28
29sub _catname { #  Will be replaced by File::Spec when it arrives
30    my($from, $to) = @_;
31    if (not defined &basename) {
32	require File::Basename;
33	import  File::Basename 'basename';
34    }
35    if ($^O eq 'VMS')  { $to = VMS::Filespec::vmspath($to) . basename($from); }
36    elsif ($^O eq 'MacOS') { $to .= ':' . basename($from); }
37    elsif ($to =~ m|\\|)   { $to .= '\\' . basename($from); }
38    else                   { $to .= '/' . basename($from); }
39}
40
41sub copy {
42    croak("Usage: copy(FROM, TO [, BUFFERSIZE]) ")
43      unless(@_ == 2 || @_ == 3);
44
45    my $from = shift;
46    my $to = shift;
47
48    my $from_a_handle = (ref($from)
49			 ? (ref($from) eq 'GLOB'
50			    || UNIVERSAL::isa($from, 'GLOB')
51                            || UNIVERSAL::isa($from, 'IO::Handle'))
52			 : (ref(\$from) eq 'GLOB'));
53    my $to_a_handle =   (ref($to)
54			 ? (ref($to) eq 'GLOB'
55			    || UNIVERSAL::isa($to, 'GLOB')
56                            || UNIVERSAL::isa($to, 'IO::Handle'))
57			 : (ref(\$to) eq 'GLOB'));
58
59    if (!$from_a_handle && !$to_a_handle && -d $to && ! -d $from) {
60	$to = _catname($from, $to);
61    }
62
63    if (defined &syscopy && \&syscopy != \&copy
64	&& !$to_a_handle
65	&& !($from_a_handle && $^O eq 'os2'))	# OS/2 cannot handle handles
66    {
67	return syscopy($from, $to);
68    }
69
70    my $closefrom = 0;
71    my $closeto = 0;
72    my ($size, $status, $r, $buf);
73    local(*FROM, *TO);
74    local($\) = '';
75
76    if ($from_a_handle) {
77	*FROM = *$from{FILEHANDLE};
78    } else {
79	$from = "./$from" if $from =~ /^\s/;
80	open(FROM, "< $from\0") or goto fail_open1;
81	binmode FROM or die "($!,$^E)";
82	$closefrom = 1;
83    }
84
85    if ($to_a_handle) {
86	*TO = *$to{FILEHANDLE};
87    } else {
88	$to = "./$to" if $to =~ /^\s/;
89	open(TO,"> $to\0") or goto fail_open2;
90	binmode TO or die "($!,$^E)";
91	$closeto = 1;
92    }
93
94    if (@_) {
95	$size = shift(@_) + 0;
96	croak("Bad buffer size for copy: $size\n") unless ($size > 0);
97    } else {
98	$size = -s FROM;
99	$size = 1024 if ($size < 512);
100	$size = $Too_Big if ($size > $Too_Big);
101    }
102
103    $! = 0;
104    for (;;) {
105	my ($r, $w, $t);
106	defined($r = sysread(FROM, $buf, $size))
107	    or goto fail_inner;
108	last unless $r;
109	for ($w = 0; $w < $r; $w += $t) {
110	    $t = syswrite(TO, $buf, $r - $w, $w)
111		or goto fail_inner;
112	}
113    }
114
115    close(TO) || goto fail_open2 if $closeto;
116    close(FROM) || goto fail_open1 if $closefrom;
117
118    # Use this idiom to avoid uninitialized value warning.
119    return 1;
120
121    # All of these contortions try to preserve error messages...
122  fail_inner:
123    if ($closeto) {
124	$status = $!;
125	$! = 0;
126	close TO;
127	$! = $status unless $!;
128    }
129  fail_open2:
130    if ($closefrom) {
131	$status = $!;
132	$! = 0;
133	close FROM;
134	$! = $status unless $!;
135    }
136  fail_open1:
137    return 0;
138}
139
140sub move {
141    my($from,$to) = @_;
142    my($copied,$fromsz,$tosz1,$tomt1,$tosz2,$tomt2,$sts,$ossts);
143
144    if (-d $to && ! -d $from) {
145	$to = _catname($from, $to);
146    }
147
148    ($tosz1,$tomt1) = (stat($to))[7,9];
149    $fromsz = -s $from;
150    if ($^O eq 'os2' and defined $tosz1 and defined $fromsz) {
151      # will not rename with overwrite
152      unlink $to;
153    }
154    return 1 if rename $from, $to;
155
156    ($sts,$ossts) = ($! + 0, $^E + 0);
157    # Did rename return an error even though it succeeded, because $to
158    # is on a remote NFS file system, and NFS lost the server's ack?
159    return 1 if defined($fromsz) && !-e $from &&           # $from disappeared
160                (($tosz2,$tomt2) = (stat($to))[7,9]) &&    # $to's there
161                ($tosz1 != $tosz2 or $tomt1 != $tomt2) &&  #   and changed
162                $tosz2 == $fromsz;                         # it's all there
163
164    ($tosz1,$tomt1) = (stat($to))[7,9];  # just in case rename did something
165    return 1 if ($copied = copy($from,$to)) && unlink($from);
166
167    ($tosz2,$tomt2) = ((stat($to))[7,9],0,0) if defined $tomt1;
168    unlink($to) if !defined($tomt1) or $tomt1 != $tomt2 or $tosz1 != $tosz2;
169    ($!,$^E) = ($sts,$ossts);
170    return 0;
171}
172
173*cp = \&copy;
174*mv = \&move;
175
176# &syscopy is an XSUB under OS/2
177*syscopy = ($^O eq 'VMS' ? \&rmscopy : \&copy) unless defined &syscopy;
178
1791;
180
181__END__
182
183=head1 NAME
184
185File::Copy - Copy files or filehandles
186
187=head1 SYNOPSIS
188
189  	use File::Copy;
190
191	copy("file1","file2");
192  	copy("Copy.pm",\*STDOUT);'
193	move("/dev1/fileA","/dev2/fileB");
194
195  	use POSIX;
196	use File::Copy cp;
197
198	$n=FileHandle->new("/dev/null","r");
199	cp($n,"x");'
200
201=head1 DESCRIPTION
202
203The File::Copy module provides two basic functions, C<copy> and
204C<move>, which are useful for getting the contents of a file from
205one place to another.
206
207=over 4
208
209=item *
210
211The C<copy> function takes two
212parameters: a file to copy from and a file to copy to. Either
213argument may be a string, a FileHandle reference or a FileHandle
214glob. Obviously, if the first argument is a filehandle of some
215sort, it will be read from, and if it is a file I<name> it will
216be opened for reading. Likewise, the second argument will be
217written to (and created if need be).
218
219B<Note that passing in
220files as handles instead of names may lead to loss of information
221on some operating systems; it is recommended that you use file
222names whenever possible.>  Files are opened in binary mode where
223applicable.  To get a consistent behavour when copying from a
224filehandle to a file, use C<binmode> on the filehandle.
225
226An optional third parameter can be used to specify the buffer
227size used for copying. This is the number of bytes from the
228first file, that wil be held in memory at any given time, before
229being written to the second file. The default buffer size depends
230upon the file, but will generally be the whole file (up to 2Mb), or
2311k for filehandles that do not reference files (eg. sockets).
232
233You may use the syntax C<use File::Copy "cp"> to get at the
234"cp" alias for this function. The syntax is I<exactly> the same.
235
236=item *
237
238The C<move> function also takes two parameters: the current name
239and the intended name of the file to be moved.  If the destination
240already exists and is a directory, and the source is not a
241directory, then the source file will be renamed into the directory
242specified by the destination.
243
244If possible, move() will simply rename the file.  Otherwise, it copies
245the file to the new location and deletes the original.  If an error occurs
246during this copy-and-delete process, you may be left with a (possibly partial)
247copy of the file under the destination name.
248
249You may use the "mv" alias for this function in the same way that
250you may use the "cp" alias for C<copy>.
251
252=back
253
254File::Copy also provides the C<syscopy> routine, which copies the
255file specified in the first parameter to the file specified in the
256second parameter, preserving OS-specific attributes and file
257structure.  For Unix systems, this is equivalent to the simple
258C<copy> routine.  For VMS systems, this calls the C<rmscopy>
259routine (see below).  For OS/2 systems, this calls the C<syscopy>
260XSUB directly.
261
262=head2 Special behavior if C<syscopy> is defined (VMS and OS/2)
263
264If both arguments to C<copy> are not file handles,
265then C<copy> will perform a "system copy" of
266the input file to a new output file, in order to preserve file
267attributes, indexed file structure, I<etc.>  The buffer size
268parameter is ignored.  If either argument to C<copy> is a
269handle to an opened file, then data is copied using Perl
270operators, and no effort is made to preserve file attributes
271or record structure.
272
273The system copy routine may also be called directly under VMS and OS/2
274as C<File::Copy::syscopy> (or under VMS as C<File::Copy::rmscopy>, which
275is the routine that does the actual work for syscopy).
276
277=over 4
278
279=item rmscopy($from,$to[,$date_flag])
280
281The first and second arguments may be strings, typeglobs, typeglob
282references, or objects inheriting from IO::Handle;
283they are used in all cases to obtain the
284I<filespec> of the input and output files, respectively.  The
285name and type of the input file are used as defaults for the
286output file, if necessary.
287
288A new version of the output file is always created, which
289inherits the structure and RMS attributes of the input file,
290except for owner and protections (and possibly timestamps;
291see below).  All data from the input file is copied to the
292output file; if either of the first two parameters to C<rmscopy>
293is a file handle, its position is unchanged.  (Note that this
294means a file handle pointing to the output file will be
295associated with an old version of that file after C<rmscopy>
296returns, not the newly created version.)
297
298The third parameter is an integer flag, which tells C<rmscopy>
299how to handle timestamps.  If it is E<lt> 0, none of the input file's
300timestamps are propagated to the output file.  If it is E<gt> 0, then
301it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
302timestamps other than the revision date are propagated; if bit 1
303is set, the revision date is propagated.  If the third parameter
304to C<rmscopy> is 0, then it behaves much like the DCL COPY command:
305if the name or type of the output file was explicitly specified,
306then no timestamps are propagated, but if they were taken implicitly
307from the input filespec, then all timestamps other than the
308revision date are propagated.  If this parameter is not supplied,
309it defaults to 0.
310
311Like C<copy>, C<rmscopy> returns 1 on success.  If an error occurs,
312it sets C<$!>, deletes the output file, and returns 0.
313
314=back
315
316=head1 RETURN
317
318All functions return 1 on success, 0 on failure.
319$! will be set if an error was encountered.
320
321=head1 AUTHOR
322
323File::Copy was written by Aaron Sherman I<E<lt>ajs@ajs.comE<gt>> in 1995,
324and updated by Charles Bailey I<E<lt>bailey@genetics.upenn.eduE<gt>> in 1996.
325
326=cut
327
328