1File::Copy(3pm) Perl Programmers Reference Guide File::Copy(3pm)
2
6 File::Copy - Copy files or filehandles
7
9 use File::Copy;
10 copy("sourcefile","destinationfile") or die "Copy failed: $!";
12 copy("Copy.pm",\*STDOUT);
13 move("/dev1/sourcefile","/dev2/destinationfile");
14 use File::Copy "cp";
16 $n = FileHandle->new("/a/file","r");
18 cp($n,"x");
19
21 The File::Copy module provides two basic functions, "copy" and "move",
22 which are useful for getting the contents of a file from one place to
23 another.
24 copy
26 The "copy" function takes two parameters: a file to copy from and a
27 file to copy to. Either argument may be a string, a FileHandle
28 reference or a FileHandle glob. Obviously, if the first argument is
29 a filehandle of some sort, it will be read from, and if it is a
30 file name it will be opened for reading. Likewise, the second
31 argument will be written to. If the second argument does not exist
32 but the parent directory does exist, then it will be created.
33 Trying to copy a file into a non-existent directory is an error.
34 Trying to copy a file on top of itself is also an error. "copy"
35 will not overwrite read-only files.
36 If the destination (second argument) already exists and is a
38 directory, and the source (first argument) is not a filehandle,
39 then the source file will be copied into the directory specified by
40 the destination, using the same base name as the source file. It's
41 a failure to have a filehandle as the source when the destination
42 is a directory.
43 Note that passing in files as handles instead of names may lead to
45 loss of information on some operating systems; it is recommended
46 that you use file names whenever possible. Files are opened in
47 binary mode where applicable. To get a consistent behaviour when
48 copying from a filehandle to a file, use "binmode" on the
49 filehandle.
50 An optional third parameter can be used to specify the buffer size
52 used for copying. This is the number of bytes from the first file,
53 that will be held in memory at any given time, before being written
54 to the second file. The default buffer size depends upon the file,
55 but will generally be the whole file (up to 2MB), or 1k for
56 filehandles that do not reference files (eg. sockets).
57 You may use the syntax "use File::Copy "cp"" to get at the "cp"
59 alias for this function. The syntax is exactly the same. The
60 behavior is nearly the same as well: as of version 2.15, "cp" will
61 preserve the source file's permission bits like the shell utility
62 cp(1) would do, while "copy" uses the default permissions for the
63 target file (which may depend on the process' "umask", file
64 ownership, inherited ACLs, etc.). If an error occurs in setting
65 permissions, "cp" will return 0, regardless of whether the file was
66 successfully copied.
67 move
69 The "move" function also takes two parameters: the current name and
70 the intended name of the file to be moved. If the destination
71 already exists and is a directory, and the source is not a
72 directory, then the source file will be renamed into the directory
73 specified by the destination.
74 If possible, move() will simply rename the file. Otherwise, it
76 copies the file to the new location and deletes the original. If
77 an error occurs during this copy-and-delete process, you may be
78 left with a (possibly partial) copy of the file under the
79 destination name.
80 You may use the "mv" alias for this function in the same way that
82 you may use the "cp" alias for "copy".
83 syscopy
85 File::Copy also provides the "syscopy" routine, which copies the
86 file specified in the first parameter to the file specified in the
87 second parameter, preserving OS-specific attributes and file
88 structure. For Unix systems, this is equivalent to the simple
89 "copy" routine, which doesn't preserve OS-specific attributes. For
90 VMS systems, this calls the "rmscopy" routine (see below). For
91 OS/2 systems, this calls the "syscopy" XSUB directly. For Win32
92 systems, this calls "Win32::CopyFile".
93 Special behaviour if "syscopy" is defined (OS/2, VMS and Win32):
95 If both arguments to "copy" are not file handles, then "copy" will
97 perform a "system copy" of the input file to a new output file, in
98 order to preserve file attributes, indexed file structure, etc.
99 The buffer size parameter is ignored. If either argument to "copy"
100 is a handle to an opened file, then data is copied using Perl
101 operators, and no effort is made to preserve file attributes or
102 record structure.
103 The system copy routine may also be called directly under VMS and
105 OS/2 as "File::Copy::syscopy" (or under VMS as
106 "File::Copy::rmscopy", which is the routine that does the actual
107 work for syscopy).
108 rmscopy($from,$to[,$date_flag])
110 The first and second arguments may be strings, typeglobs, typeglob
111 references, or objects inheriting from IO::Handle; they are used in
112 all cases to obtain the filespec of the input and output files,
113 respectively. The name and type of the input file are used as
114 defaults for the output file, if necessary.
115 A new version of the output file is always created, which inherits
117 the structure and RMS attributes of the input file, except for
118 owner and protections (and possibly timestamps; see below). All
119 data from the input file is copied to the output file; if either of
120 the first two parameters to "rmscopy" is a file handle, its
121 position is unchanged. (Note that this means a file handle
122 pointing to the output file will be associated with an old version
123 of that file after "rmscopy" returns, not the newly created
124 version.)
125 The third parameter is an integer flag, which tells "rmscopy" how
127 to handle timestamps. If it is < 0, none of the input file's
128 timestamps are propagated to the output file. If it is > 0, then
129 it is interpreted as a bitmask: if bit 0 (the LSB) is set, then
130 timestamps other than the revision date are propagated; if bit 1 is
131 set, the revision date is propagated. If the third parameter to
132 "rmscopy" is 0, then it behaves much like the DCL COPY command: if
133 the name or type of the output file was explicitly specified, then
134 no timestamps are propagated, but if they were taken implicitly
135 from the input filespec, then all timestamps other than the
136 revision date are propagated. If this parameter is not supplied,
137 it defaults to 0.
138 "rmscopy" is VMS specific and cannot be exported; it must be
140 referenced by its full name, e.g.:
141 File::Copy::rmscopy($from, $to) or die $!;
143 Like "copy", "rmscopy" returns 1 on success. If an error occurs,
145 it sets $!, deletes the output file, and returns 0.
146
148 All functions return 1 on success, 0 on failure. $! will be set if an
149 error was encountered.
150
152 Before calling copy() or move() on a filehandle, the caller should
153 close or flush() the file to avoid writes being lost. Note that this is
154 the case even for move(), because it may actually copy the file,
155 depending on the OS-specific implementation, and the underlying
156 filesystem(s).
157
159 File::Copy was written by Aaron Sherman <ajs@ajs.com> in 1995, and
160 updated by Charles Bailey <bailey@newman.upenn.edu> in 1996.
161perl v5.34.0 2021-10-18 File::Copy(3pm)