summaryrefslogtreecommitdiffstats
path: root/upstream/debian-unstable/man3/File::Copy.3perl
blob: c2d19895f539e978579ebd8a02051e8384258ed9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
.\" -*- mode: troff; coding: utf-8 -*-
.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>.
.ie n \{\
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "File::Copy 3perl"
.TH File::Copy 3perl 2024-01-12 "perl v5.38.2" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH NAME
File::Copy \- Copy files or filehandles
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\&        use File::Copy;
\&
\&        copy("sourcefile", "destinationfile") or die "Copy failed: $!";
\&        copy("Copy.pm", \e*STDOUT);
\&        move("/dev1/sourcefile", "/dev2/destinationfile");
\&
\&        use File::Copy "cp";
\&
\&        my $n = FileHandle\->new("/a/file", "r");
\&        cp($n, "x");
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
The File::Copy module provides two basic functions, \f(CW\*(C`copy\*(C'\fR and
\&\f(CW\*(C`move\*(C'\fR, which are useful for getting the contents of a file from
one place to another.
.IP copy 4
.IX Xref "copy cp"
.IX Item "copy"
The \f(CW\*(C`copy\*(C'\fR function takes two
parameters: a file to copy from and a file to copy to. Either
argument may be a string, a FileHandle reference or a FileHandle
glob. Obviously, if the first argument is a filehandle of some
sort, it will be read from, and if it is a file \fIname\fR it will
be opened for reading. Likewise, the second argument will be
written to. If the second argument does not exist but the parent
directory does exist, then it will be created. Trying to copy
a file into a non-existent directory is an error.
Trying to copy a file on top of itself is also an error.
\&\f(CW\*(C`copy\*(C'\fR will not overwrite read-only files.
.Sp
If the destination (second argument) already exists and is a directory,
and the source (first argument) is not a filehandle, then the source
file will be copied into the directory specified by the destination,
using the same base name as the source file.  It's a failure to have a
filehandle as the source when the destination is a directory.
.Sp
\&\fBNote that passing in
files as handles instead of names may lead to loss of information
on some operating systems; it is recommended that you use file
names whenever possible.\fR  Files are opened in binary mode where
applicable.  To get a consistent behaviour when copying from a
filehandle to a file, use \f(CW\*(C`binmode\*(C'\fR on the filehandle.
.Sp
An optional third parameter can be used to specify the buffer
size used for copying. This is the number of bytes from the
first file, that will be held in memory at any given time, before
being written to the second file. The default buffer size depends
upon the file, but will generally be the whole file (up to 2MB), or
1k for filehandles that do not reference files (eg. sockets).
.Sp
You may use the syntax \f(CW\*(C`use File::Copy "cp"\*(C'\fR to get at the \f(CW\*(C`cp\*(C'\fR
alias for this function. The syntax is \fIexactly\fR the same.  The
behavior is nearly the same as well: as of version 2.15, \f(CW\*(C`cp\*(C'\fR will
preserve the source file's permission bits like the shell utility
\&\f(CWcp(1)\fR would do with default options, while \f(CW\*(C`copy\*(C'\fR uses the default
permissions for the target file (which may depend on the process'
\&\f(CW\*(C`umask\*(C'\fR, file ownership, inherited ACLs, etc.).  That is, if the
destination file already exists, \f(CW\*(C`cp\*(C'\fR will leave its permissions
unchanged; otherwise the permissions are taken from the source file
and modified by the \f(CW\*(C`umask\*(C'\fR.  If an error occurs in setting
permissions, \f(CW\*(C`cp\*(C'\fR will return 0, regardless of whether the file was
successfully copied.
.IP move 4
.IX Xref "move mv rename"
.IX Item "move"
The \f(CW\*(C`move\*(C'\fR function also takes two parameters: the current name
and the intended name of the file to be moved.  If the destination
already exists and is a directory, and the source is not a
directory, then the source file will be renamed into the directory
specified by the destination.
.Sp
If possible, \fBmove()\fR will simply rename the file.  Otherwise, it copies
the file to the new location and deletes the original.  If an error occurs
during this copy-and-delete process, you may be left with a (possibly partial)
copy of the file under the destination name.
.Sp
You may use the \f(CW\*(C`mv\*(C'\fR alias for this function in the same way that
you may use the \f(CW\*(C`cp\*(C'\fR alias for \f(CW\*(C`copy\*(C'\fR.
.IP syscopy 4
.IX Xref "syscopy"
.IX Item "syscopy"
File::Copy also provides the \f(CW\*(C`syscopy\*(C'\fR routine, which copies the
file specified in the first parameter to the file specified in the
second parameter, preserving OS-specific attributes and file
structure.  For Unix systems, this is equivalent to the simple
\&\f(CW\*(C`copy\*(C'\fR routine, which doesn't preserve OS-specific attributes.  For
VMS systems, this calls the \f(CW\*(C`rmscopy\*(C'\fR routine (see below).  For OS/2
systems, this calls the \f(CW\*(C`syscopy\*(C'\fR XSUB directly. For Win32 systems,
this calls \f(CW\*(C`Win32::CopyFile\*(C'\fR.
.Sp
\&\fBSpecial behaviour if \fR\f(CB\*(C`syscopy\*(C'\fR\fB is defined (OS/2, VMS and Win32)\fR:
.Sp
If both arguments to \f(CW\*(C`copy\*(C'\fR are not file handles,
then \f(CW\*(C`copy\*(C'\fR will perform a "system copy" of
the input file to a new output file, in order to preserve file
attributes, indexed file structure, \fIetc.\fR  The buffer size
parameter is ignored.  If either argument to \f(CW\*(C`copy\*(C'\fR is a
handle to an opened file, then data is copied using Perl
operators, and no effort is made to preserve file attributes
or record structure.
.Sp
The system copy routine may also be called directly under VMS and OS/2
as \f(CW\*(C`File::Copy::syscopy\*(C'\fR (or under VMS as \f(CW\*(C`File::Copy::rmscopy\*(C'\fR, which
is the routine that does the actual work for syscopy).
.IP rmscopy($from,$to[,$date_flag]) 4
.IX Xref "rmscopy"
.IX Item "rmscopy($from,$to[,$date_flag])"
The first and second arguments may be strings, typeglobs, typeglob
references, or objects inheriting from IO::Handle;
they are used in all cases to obtain the
\&\fIfilespec\fR of the input and output files, respectively.  The
name and type of the input file are used as defaults for the
output file, if necessary.
.Sp
A new version of the output file is always created, which
inherits the structure and RMS attributes of the input file,
except for owner and protections (and possibly timestamps;
see below).  All data from the input file is copied to the
output file; if either of the first two parameters to \f(CW\*(C`rmscopy\*(C'\fR
is a file handle, its position is unchanged.  (Note that this
means a file handle pointing to the output file will be
associated with an old version of that file after \f(CW\*(C`rmscopy\*(C'\fR
returns, not the newly created version.)
.Sp
The third parameter is an integer flag, which tells \f(CW\*(C`rmscopy\*(C'\fR
how to handle timestamps.  If it is < 0, none of the input file's
timestamps are propagated to the output file.  If it is > 0, then
it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
timestamps other than the revision date are propagated; if bit 1
is set, the revision date is propagated.  If the third parameter
to \f(CW\*(C`rmscopy\*(C'\fR is 0, then it behaves much like the DCL COPY command:
if the name or type of the output file was explicitly specified,
then no timestamps are propagated, but if they were taken implicitly
from the input filespec, then all timestamps other than the
revision date are propagated.  If this parameter is not supplied,
it defaults to 0.
.Sp
\&\f(CW\*(C`rmscopy\*(C'\fR is VMS specific and cannot be exported; it must be
referenced by its full name, e.g.:
.Sp
.Vb 1
\&  File::Copy::rmscopy($from, $to) or die $!;
.Ve
.Sp
Like \f(CW\*(C`copy\*(C'\fR, \f(CW\*(C`rmscopy\*(C'\fR returns 1 on success.  If an error occurs,
it sets \f(CW$!\fR, deletes the output file, and returns 0.
.SH RETURN
.IX Header "RETURN"
All functions return 1 on success, 0 on failure.
$! will be set if an error was encountered.
.SH NOTES
.IX Header "NOTES"
Before calling \fBcopy()\fR or \fBmove()\fR on a filehandle, the caller should
close or \fBflush()\fR the file to avoid writes being lost. Note that this
is the case even for \fBmove()\fR, because it may actually copy the file,
depending on the OS-specific implementation, and the underlying
filesystem(s).
.SH AUTHOR
.IX Header "AUTHOR"
File::Copy was written by Aaron Sherman \fI<ajs@ajs.com>\fR in 1995,
and updated by Charles Bailey \fI<bailey@newman.upenn.edu>\fR in 1996.