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cp (Unix)

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Unix command utility

cp
Example usage of`cp` command
Original author(s)	AT&T Bell Laboratories
Developer(s)	Variousopen-source andcommercial developers
Initial release	November 3, 1971; 53 years ago (1971-11-03)
Written in	Plan 9:C
Operating system	Unix,Unix-like,Plan 9,Inferno,KolibriOS
Platform	Cross-platform
Type	Command
License	coreutils:GPLv3 Plan 9:MIT License

Incomputing,cp is acommand in variousUnix andUnix-like operating systems forcopying files anddirectories. The command has three principal modes of operation, expressed by the types of arguments presented to the program for copying a file to another file, one or more files to a directory, or for copying entire directories to another directory.^[1]

The utility further accepts various command line option flags to detail the operations performed. The two major specifications arePOSIXcp andGNUcp. GNUcp has many additional options over the POSIX version.^[2]

The command is also available in theEFI shell.^[3]

History

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cp was part ofVersion 1 Unix.^[4] The version ofcp bundled inGNU coreutils was written by Torbjorn Granlund, David MacKenzie, and Jim Meyering.^[5]

Operating modes

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cp has three principal modes of operation. These modes are inferred from the type and count of arguments presented to the program upon invocation.

When the program has two arguments of path names to files, the program copies the contents of the first file to the second file, creating the second file if necessary.
When the program has one or more arguments of path names of files and following those an argument of a path to a directory, then the program copies each source file to the destination directory, creating any files not already existing.
When the program's arguments are the path names to two directories, cp copies all files in the source directory to the destination directory, creating any files or directories needed. This mode of operation requires an additional option flag, typicallyr, to indicate the recursive copying of directories. If the destination directory already exists, the source is copied into the destination, while a new directory is created if the destination does not exist.

Usage

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Copying a file to another file:

cp [-fHip][--] sourcefile targetfile

Copying file(s) to a directory

cp [-fHip] [--] sourcefile... targetdirectory

Copying a directory to a directory (-r or -R must be used)

cp -r|-R [-fHip] [--]  sourcedirectory... targetdirectory

Option flags

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-f (force) – specifies removal of the target file if it cannot be opened for write operations. The removal precedes any copying performed by thecp command.
-H (dereference) – makes thecp command followsymbolic links (symlinks) so that the destination has the target file rather than a symlink to the target.
-i (interactive) – prompts with the name of a file to be overwritten. This occurs if theTargetDirectory orTargetFile parameter contains a file with the same name as a file specified in theSourceFile orSourceDirectory parameter. If one entersy (or the locale's equivalent ofy), thecp command continues. Any other answer prevents thecp command from overwriting the file.
-n (noclobbering) – prevents accidentally overwriting any files
-p (preserve) – the-p flag preserves the following characteristics of each source path in the corresponding target: the time of thelast data modification and thetime of the last access, the ownership (only if it has permissions to do this), and the file permission-bits.
-R or-r (recursive) – copy directories recursively

Examples

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Creating a copy of a file in the current directory:

cp prog.c prog.bak

This copies prog.c to prog.bak. If the prog.bak file does not already exist, the cp command creates it. If it does exist, the cp command replaces its contents with the contents of the prog.c file.

Copy two files in the current directory into another directory:

cp jones smith /home/nick/clients

This copies the filesjones to /home/nick/clients/jones andsmith to /home/nick/clients/smith.

Copy a file to a new file and preserve the modification date, time, and access control list associated with the source file:

cp -p smith smith.jr

This copies the smith file to the smith.jr file. Instead of creating the file with the current date and time stamp, the system gives the smith.jr file the same date and time as the smith file. The smith.jr file also inherits the smith file's access control protection.

Copy a directory, including all its files and subdirectories, to another directory:

cp -R /home/nick/clients /home/nick/customers

This copies the directoryclients, including all its files, subdirectories, and the files in those subdirectories, to the directorycustomers/clients. Some Unix systems behave differently in this mode, depending on the termination of directory paths. Usingcp -R /home/nick/clients/ /home/nick/customers on a GNU system it behaves as expected; however, on a BSD system, it copies all thecontents of the "clients" directory, instead of the directoryclients itself. The same happens in both GNU and BSD systems if the path of the source directory ends in . or .. (with or without trailing slash).

The copying of a file to an existing file is performed by opening the existing file in update mode, thereby preserving the files inode, which requires write access and results in the target file retaining the permissions it had originally.

Related Unix commands

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cpio – copy an entire directory structure from one place to another
tar – create an archive of files
link – system call to create a link to a file or directory
ln – create a link to a file or directory
mv – move a file or directory
rm – remove a file or directory
unlink – system call to remove a file or directory
chmod – change the mode (aka permissions) on a file or directory
chown – change ownership on a file or directory
chgrp – change group on a file or directory
uucp – unix to unix copy
scp – secure copy over SSH
progress,^[6]^[7] Linux tool to show progress for cp, mv, dd.

References

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^"Cp(1) - Linux manual page".
^"GNU Coreutils: cp invocation".GNU.
^"EFI Shells and Scripting".Intel. Retrieved2013-09-25.
^McIlroy, M. D. (1987).A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986(PDF) (Technical report). CSTR. Bell Labs. 139.
^"Cp(1): Copy files/Directories - Linux man page".
^"Progress(1) - Linux man page".
^"Progress - Coreutils Progress Viewer".GitHub. 14 November 2021.

External links

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cp – Shell and Utilities Reference,The Single UNIX Specification, Version 4 fromThe Open Group
cp(1) – FreeBSD General CommandsManual
cp(1) – NetBSD General CommandsManual
cp(1) – OpenBSD General CommandsManual
cp(1) – Solaris 11.4 User Commands ReferenceManual
cp(1) – Linux User CommandsManual
cp(1) – Plan 9 Programmer's Manual, Volume 1

v t e Unix command-line interface programs andshell builtins
File system	cat chattr chmod chown chgrp cksum cmp cp dd du df file fuser ln ls mkdir mv pax pwd rm rmdir split tee touch type umask
Processes	at bg crontab fg kill nice ps time
User environment	env exit logname mesg talk tput uname who write
Text processing	awk basename comm csplit cut diff dirname ed ex fold head iconv join m4 more nl paste patch printf read sed sort strings tail tr troff uniq vi wc xargs
Shell builtins	alias cd echo test unset wait
Searching	find grep
Documentation	man
Software development	ar ctags lex make nm strip yacc
Miscellaneous	bc cal expr lp od sleep true and false
Categories Standard Unix programs Unix SUS2008 utilities List

v t e Plan 9 command-line interface programs andshell builtins
File system	chmod chgrp cmp cp dd du file gzip ls mkdir pwd rm split tee touch
Processes	kill ps
User environment	passwd who
Text processing	awk basename comm diff ed eqn join sed sort spell strings tail tr troff uniq wc
Shell builtins	echo test
Networking	ip/ipconfig ip/ping netstat
Searching	grep
Software development	ar hoc lex nm strip yacc
Miscellaneous	bc cal fortune sleep
Category

v t e GNU Core Utilities command-line interface programs
File system	chcon chmod chown chgrp cksum cp dd df dir dircolors install ln ls mkdir mkfifo mknod mktemp mv realpath rm rmdir shred sync touch truncate vdir
Text utilities	b2sum base32 base64 cat cksum comm csplit cut expand fmt fold head join md5sum nl numfmt od paste ptx pr sha1sum shuf sort split sum tac tail tr tsort unexpand uniq wc
Shell utilities	arch basename chroot date dirname du echo env expr factor false groups hostid id link logname nice nohup nproc pathchk pinky printenv printf pwd readlink runcon seq sleep stat stdbuf stty tee test timeout true tty uname unlink uptime users who whoami yes