File::Copy(3p) Perl Programmers Reference Guide File::Copy(3p)
File::Copy - Copy files or filehandles
use File::Copy;
copy("file1","file2") or die "Copy failed: $!";
copy("Copy.pm",\*STDOUT);
move("/dev1/fileA","/dev2/fileB");
use File::Copy "cp";
$n = FileHandle->new("/a/file","r");
cp($n,"x");
The File::Copy module provides two basic functions, "copy"
and "move", which are useful for getting the contents of a
file from one place to another.
+ The "copy" 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 name it
will be opened for reading. Likewise, the second argu-
ment will be written to (and created if need be). Try-
ing to copy a file on top of itself is a fatal error.
Note that passing in files as handles instead of names
may lead to loss of information on some operating sys-
tems; it is recommended that you use file names whenever
possible. Files are opened in binary mode where appli-
cable. To get a consistent behaviour when copying from
a filehandle to a file, use "binmode" on the filehandle.
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 wil 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).
You may use the syntax "use File::Copy "cp"" to get at
the "cp" alias for this function. The syntax is exactly
the same.
+ The "move" 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
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source file will be renamed into the directory specified
by the destination.
If possible, move() will simply rename the file. Other-
wise, 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 par-
tial) copy of the file under the destination name.
You may use the "mv" alias for this function in the same
way that you may use the "cp" alias for "copy".
File::Copy also provides the "syscopy" routine, which copies
the file specified in the first parameter to the file speci-
fied in the second parameter, preserving OS-specific attri-
butes and file structure. For Unix systems, this is
equivalent to the simple "copy" routine, which doesn't
preserve OS-specific attributes. For VMS systems, this
calls the "rmscopy" routine (see below). For OS/2 systems,
this calls the "syscopy" XSUB directly. For Win32 systems,
this calls "Win32::CopyFile".
On Mac OS (Classic), "syscopy" calls
"Mac::MoreFiles::FSpFileCopy", if available.
Special behaviour if "syscopy" is defined (OS/2, VMS and
Win32)
If both arguments to "copy" are not file handles, then
"copy" will perform a "system copy" of the input file to a
new output file, in order to preserve file attributes,
indexed file structure, etc. The buffer size parameter is
ignored. If either argument to "copy" 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.
The system copy routine may also be called directly under
VMS and OS/2 as "File::Copy::syscopy" (or under VMS as
"File::Copy::rmscopy", which is the routine that does the
actual work for syscopy).
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 filespec of the input and output files, respec-
tively. The name and type of the input file are used as
defaults for the output file, if necessary.
A new version of the output file is always created,
which inherits the structure and RMS attributes of the
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File::Copy(3p) Perl Programmers Reference Guide File::Copy(3p)
input file, except for owner and protections (and possi-
bly timestamps; see below). All data from the input
file is copied to the output file; if either of the
first two parameters to "rmscopy" 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 "rmscopy"
returns, not the newly created version.)
The third parameter is an integer flag, which tells
"rmscopy" 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 "rmscopy" 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 revi-
sion date are propagated. If this parameter is not sup-
plied, it defaults to 0.
Like "copy", "rmscopy" returns 1 on success. If an
error occurs, it sets $!, deletes the output file, and
returns 0.
All functions return 1 on success, 0 on failure. $! will be
set if an error was encountered.
+ On Mac OS (Classic), the path separator is ':', not '/',
and the current directory is denoted as ':', not '.'.
You should be careful about specifying relative path-
names. While a full path always begins with a volume
name, a relative pathname should always begin with a
':'. If specifying a volume name only, a trailing ':'
is required.
E.g.
copy("file1", "tmp"); # creates the file 'tmp' in the current directory
copy("file1", ":tmp:"); # creates :tmp:file1
copy("file1", ":tmp"); # same as above
copy("file1", "tmp"); # same as above, if 'tmp' is a directory (but don't do
# that, since it may cause confusion, see example #1)
copy("file1", "tmp:file1"); # error, since 'tmp:' is not a volume
copy("file1", ":tmp:file1"); # ok, partial path
copy("file1", "DataHD:"); # creates DataHD:file1
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move("MacintoshHD:fileA", "DataHD:fileB"); # moves (don't copies) files from one
# volume to another
File::Copy was written by Aaron Sherman <ajs@ajs.com> in
1995, and updated by Charles Bailey
<bailey@newman.upenn.edu> in 1996.
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