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The cp command in Unix can copy one or several files. For each file it reads the contents of a file and creates a new file or overwrites an existing file. If can also recursively copy subtrees of the Unix directory tree.
The key problem with cp utility is that it does not preserve timestamp of the file. You need to use option -p to force this behaviour.
-p -- Preserve the characteristics of the source_file. Copy the contents, modification times, and permission modes of the source_file to the destination files.
There are two basic formats of the cp command that allow you to:
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Following is the general format of the cp command.
cp [ -ip ] source_file destination_file cp [ -ipr ] source_file_list destination_directory cp -r [ -ip ] source_directory destination_directory
The following list describes typical three options that may be used to control how cp functions.
The following list describes the arguments that may be passed to the cp command.
| source_file | The existing file that will be copied |
| source_file_list | The name of files and/or directories to be copied to a new destination directory |
| destination_file | The name of the file the new copy will be named |
| destination_directory | The name of the directory where a copy of the files will be made |
| source_directory | The name of the directory from where copies are read |
The first format copies one ordinary file to a new file. The source_file is the pathname of the file being copied. The destination_file is the pathname of the file being copied to by cp.
The second format will copy one or more files to a specific directory. The source_file_list is a list of pathnames of the files being copied. If you specify a directory with the -r option, the entire directory tree is copied to the destination directory.
The third format allows you to copy an entire directory structure to a new directory.
If the destination_file exists and you have write permissions, cp will overwrite the contents of the file. The access permissions and ownership of the overwritten file will be used for the new destination_file.
If the destination_file does not exist, the access permissions of the source_file are used. Your ownership and group IDs are used for the new file if you are the user performing the cp command.
You cannot copy a file to itself.
Some common formats are:
cp letter letter.bak # make a backup copy of letter cp letter ../tmp # copy letter to temporary working directory cp letter ../LTRS # copy letter to original location (mv is better) cp /dev/tty note # copy input from keyboard to file "note"
For copying directories you can also use rsync
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It's also possible by using
rsync, for example: |
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Feb 12, 2019 | www.linuxtechi.com
Example:6) Archive files and directory during copy (-a)While copying a directory using cp command we generally use -r or -R option, but in place of -r option we can use '-a' which will archive the files and directory during copy, example is shown below,
root@linuxtechi:~# cp -a /home/linuxtechi /mnt/backup/ root@linuxtechi:~# ls -l /mnt/backup/linuxtechi/ total 24 drwxr-xr-x 2 root root 4096 Feb 3 17:41 data -rw-r--r-- 1 root root 7 Feb 3 17:39 file_1.txt -rw-r--r-- 1 root root 7 Feb 3 17:39 file_2.txt -rw-r--r-- 1 root root 7 Feb 3 17:39 file_3.txt -rw-r--r-- 1 root root 7 Feb 3 17:39 file_4.txt -rw-r--r-- 1 root root 7 Feb 3 17:40 file_5txt -rw-r--r-- 1 root root 0 Feb 3 17:39 file_5.txt root@linuxtechi:~#Example:7) Copy only when source file is newer than the target file (-u)There can be some scenarios where you want copy the files only if the source files are newer than the destination ones. This can be easily achieved using " -u " option in the cp command.
In the Example:6 we have copied the linuxtechi home directory to /mnt/backup folder, in the linuxtechi home folder we have 5 txt files, let's edit couple of them and then copy all the txt files using "cp -u".
root@linuxtechi:~# cd /home/linuxtechi/ root@linuxtechi:/home/linuxtechi# echo "LinuxRocks" >> file_1.txt root@linuxtechi:/home/linuxtechi# echo "LinuxRocks" >> file_4.txt root@linuxtechi:/home/linuxtechi# cp -v -u file_*.txt /mnt/backup/linuxtechi/ 'file_1.txt' -> '/mnt/backup/linuxtechi/file_1.txt' 'file_4.txt' -> '/mnt/backup/linuxtechi/file_4.txt' root@linuxtechi:/home/linuxtechi#Example:8) Do not overwrite the existing file while copying (-n)There are some scenarios where you don't want to overwrite the existing destination files while copying. This can be accomplished using the option '-n' in 'cp' command
root@linuxtechi:~# cp -i /etc/passwd /mnt/backup/ cp: overwrite '/mnt/backup/passwd'?As you can see in above command, it is prompting us to overwrite the existing file, if you use -n then it will not prompt for the overwrite and also will not overwrite the existing file.
root@linuxtechi:~# cp -n /etc/passwd /mnt/backup/ root@linuxtechi:~#Example:9) Creating symbolic links using cp command (-s)Let's assume we want to create symbolic link of a file instead copying using cp command, for such scenarios use '-s' option in cp command, example is shown below
root@linuxtechi:~# cp -s /home/linuxtechi/file_1.txt /mnt/backup/ root@linuxtechi:~# cd /mnt/backup/ root@linuxtechi:/mnt/backup# ls -l file_1.txt lrwxrwxrwx 1 root root 27 Feb 5 18:37 file_1.txt -> /home/linuxtechi/file_1.txt root@linuxtechi:/mnt/backup#Example:10) Creating Hard link using cp command (-l)If you want to create hard link of a file instead copy using cp command, then use '-l' option. example is shown below,
root@linuxtechi:~# cp -l /home/linuxtechi/devops.txt /mnt/backup/ root@linuxtechi:~#As we know in hard link, source and linked file will have the same inode numbers, let's verify this using following commands,
root@linuxtechi:~# ls -li /mnt/backup/devops.txt 918196 -rw-r--r-- 2 root root 37 Feb 5 20:02 /mnt/backup/devops.txt root@linuxtechi:~# ls -li /home/linuxtechi/devops.txt 918196 -rw-r--r-- 2 root root 37 Feb 5 20:02 /home/linuxtechi/devops.txt root@linuxtechi:Example:11) Copying attributes from source to destination (–attributes-only)If you want to copy only the attributes from source to destination using cp command, then use option " –attributes-only "
root@linuxtechi:/home/linuxtechi# cp --attributes-only /home/linuxtechi/distributions.txt /mnt/backup/ root@linuxtechi:/home/linuxtechi# ls -l /home/linuxtechi/distributions.txt -rw-r--r-- 1 root root 41 Feb 5 19:31 /home/linuxtechi/distributions.txt root@linuxtechi:/home/linuxtechi# ls -l /mnt/backup/distributions.txt -rw-r--r-- 1 root root 0 Feb 5 19:34 /mnt/backup/distributions.txt root@linuxtechi:/home/linuxtechi#In the above command, we have copied the distribution.txt file from linuxtechi home directory to /mnt/backup folder, if you have noticed, only the attributes are copied, and content is skipped. Size of distribution.txt under /mn/backup folder is zero bytes.
Example:12) Creating backup of existing destination file while copying (–backup)Default behavior of cp command is to overwrite the file on destination if the same file exists, if you want to make a backup of existing destination file during the copy operation then use ' –backup ' option, example is shown below,
root@linuxtechi:~# cp --backup=simple -v /home/linuxtechi/distributions.txt /mnt/backup/distributions.txt '/home/linuxtechi/distributions.txt' -> '/mnt/backup/distributions.txt' (backup: '/mnt/backup/distributions.txt~') root@linuxtechi:~#If you have noticed, backup has been created and appended tilde symbol at end of file. backup option accept following parameters
- none, off – never make backups
- numbered, t – make numbered backups
- existing, nil – numbered if numbered backups exist, simple otherwise
- simple, never – always make simple backups
Example:13) Preserve mode, ownership and timestamps while copying (-p)If you want to preserve the file attributes like mode, ownership and timestamps while copying then use -p option in cp command, example is demonstrated below,
root@linuxtechi:~# cd /home/linuxtechi/ root@linuxtechi:/home/linuxtechi# cp -p devops.txt /mnt/backup/ root@linuxtechi:/home/linuxtechi# ls -l devops.txt -rw-r--r-- 1 root root 37 Feb 5 20:02 devops.txt root@linuxtechi:/home/linuxtechi# ls -l /mnt/backup/devops.txt -rw-r--r-- 1 root root 37 Feb 5 20:02 /mnt/backup/devops.txt root@linuxtechi:/home/linuxtechi#Example:14) Do not follow symbolic links in Source while copying (-P)If you do not want to follow the symbolic links of source while copying then use -P option in cp command, example is shown below
root@linuxtechi:~# cd /home/linuxtechi/ root@linuxtechi:/home/linuxtechi# ls -l /opt/nix-release.txt lrwxrwxrwx 1 root root 14 Feb 9 12:28 /opt/nix-release.txt -> os-release.txt root@linuxtechi:/home/linuxtechi# root@linuxtechi:/home/linuxtechi# cp -P os-release.txt /mnt/backup/ root@linuxtechi:/home/linuxtechi# ls -l /mnt/backup/os-release.txt -rw-r--r-- 1 root root 35 Feb 9 12:29 /mnt/backup/os-release.txt root@linuxtechi:/home/linuxtechi#Note: Default behavior of cp command is to follow the symbolic links in source while copying.
Example:15) Copy the files and directory forcefully using -f optionThere can be some scenarios where existing destination file cannot be opened and removed. And if you have healthy file which can be copied in place of existing destination file, then use cp command along with -f option
root@linuxtechi:/home/linuxtechi# cp -f distributions.txt /mnt/backup/ root@linuxtechi:/home/linuxtechi#Example:16) Copy sparse files using sparse option in cp commandSparse is a regular file which contains long sequence of zero bytes that doesn't consume any physical disk block. One of benefit of sparse file is that it does not consume much disk space and read operation on that file would be quite fast.
Let's assume we have sparse cloud image named as "ubuntu-cloud.img"
root@linuxtechi:/home/linuxtechi# du -sh ubuntu-cloud.img 12M ubuntu-cloud.img root@linuxtechi:/home/linuxtechi# cp --sparse=always ubuntu-cloud.img /mnt/backup/ root@linuxtechi:/home/linuxtechi# du -sh /mnt/backup/ubuntu-cloud.img 0 /mnt/backup/ubuntu-cloud.img root@linuxtechi:/home/linuxtechi#Different options can be used while using sparse parameter in cp command,
- sparse=auto
- sparse-always
- sparse=never
That's all from this article, I hope it helps you to understand the cp command more effectively. Please do share your feedback and comments
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www.softpanorama.org
If destination does not exist it behaves as rename command but if destination exists and is directory it move it one level up
For example, if you have directories /home and home2 and want to move all subdirectories from /home2 to /home and the directory /home is empty you can't use
mv home2 homeif you forget to remove the directory /home, mv silently will create /home/home2 directory and you have a problem if this is user home directories.
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www.vanityfair.com
-p -- Preserve the characteristics of the source_file. Copy the contents, modification times, and permission modes of the source_file to the destination files.
You might wish to create an alias
alias cp='cp -p'as I can't imagine case where regular Unix behaviour is desirable.
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Contents:
Introduction
You could say, "This is not a problem for me because I can copy files with the cp or cp -r commands or move files with the mv command." However, sometimes you can break something and lose data.
I recommend you avoid such solutions as the cp or mv commands when you need to copy or move big files, large numbers of files, or large amounts of data. Also, avoid using commands such as cp or mv when you need to keep the same owner, group, permissions, and all the other information about the data.
Caveats
NFS
You can see problems when the destination or source directory is mounted on a local machine from a remote machine via NFS or through the network with any other protocol. To avoid such problems check the source and destination directories via commands. For example:
# df -k <directory>
where <directory> - source or destination directoryOr use this for the Solaris 9 Operating System (OS) and later versions:
# df -h <directory>
where <directory> - source or destination directoryExample:
# df -k /source_directory Filesystem kbytes used avail capacity Mounted on 127.0.0.1:/source 34750583 28174655 6228423 82% /source_directoryHere the directory /source from the host with the IP address 127.0.0.1 (in this case localhost) is mounted on a local machine under the directory /source_directory. To check what type of service is used to mount the directory, run a command such as the following:
# mount -v | grep "<directory>" where <directory> - source or destination directory
Symbolic Links
You can see problems when the destination or source directory -- or even worse, the subdirectories -- are linked in the source directory.
When you run the cp -r command on the directory that contains symbolic links, the links in the destination directory will be changed to the real data to which those links pointed. If you use the cp -r command directory to copy about 1 Gbyte of data that contains large quantities of links, the destination will be 1 Gbyte plus all the data to which those links pointed. Sometimes the result could be huge and could overload your system.
To check if the source directory contains symbolic links, do the following:
# cd <directory> where <directory> - source or destination directory # find . -type link | moreTo count the number of links, use this:
# find . -type link | wcHere is the result of copying directory example01 to the new one, example02, using the command cp -r ./example01 ./example02:
# find ./example01 -type link | wc 2440 2440 171743 # du -ks ./example01 2772092 ./example01 # find ./example02 -type link | wc 0 0 0 # du -ks ./example02 6326172 ./example02Unknown Destination
Problems can surface when you are not familiar with the real location, destination, or source directory because they may point somewhere else.
For example:
# df -k /source_directory Filesystem kbytes used avail capacity Mounted on /dev/dsk/c0t0d0s0 34750583 28174655 6228423 82% /source_directory # df -k /destination_directory Filesystem kbytes used avail capacity Mounted on 127.0.0.1:/destination 34750583 28174655 6228423 82% /destination_directoryHere /source_directory is the directory created on a local disk (on the root partition). /destination_directory is the directory /destination on the host with the IP address 127.0.0.1 (in this case localhost), mounted on a local machine. For the purpose of this example, the IP address is localhost. However, in a real scenario, it could be an IP from a different subnet, and the packets (data) would be transferred through the network and who knows where.
When the source or destination directory is mounted through the network, you need to know the following:
- The real way to reach such a destination or source directory
- How long it takes to copy data to and from the directory
- Whether the data will be copied through any other machines or devices (like network accelerators)
The best way is to copy some example data to the destination and get a measurement.
Problems With Access
If you are unfamiliar with how to access a destination or source directory, you may be unable to access the directories or subdirectories.
When you decide to move data using the mv command, make sure that no processes are running in the source directory that will be moved.
Sometimes you can't access the mounted directory because you have the wrong permissions on the remote host for the directory you are trying to mount. Make sure that the destination directory is not mounted as a read-only file system. For example:
# df -k /destination_directory Filesystem kbytes used avail capacity Mounted on 127.0.0.1:/destination 34750583 28174655 6228423 82% /destination_directory # mount -v | grep "<directory>"where <directory> - destination directory
Also, check that no read-only flags are set up. The best way is to try to write an example file to the destination before copying or moving large amounts of data.
Interruptions During the Copying or Moving Process
Various problems are possible, for example, if you are using the mv command from the source to the destination directory and one of them is mounted through the network. If the network becomes unavailable while the files are being moved, or you kill the terminal or kill the data moving process by mistake, data will be moved partially and you also can lose data.
A problem also occurs if you run the cp command from the source to the destination directory, with one of them mounted through the network, and the network becomes unavailable while files are being copied. In this case data will be moved partially.
When you do such moving of data remotely and, for example, you export DISPLAY to your machine, there is a high probability that the process could be interrupted. So make sure that the place from which you execute such commands is stable.
To check the terminal name, do the following:
# tty /dev/console # tty /dev/pts/1If you are logged in to the console you also have control during the reboot. Consider using the nohup command to avoid interruptions caused by long-running processes.
Moving Between Different Devices
It takes much longer to move files and directories via the mv command among directories that are not created on the same partition or disks than it does to move directories sharing the same partition. (On the same partition, this mv command works at once, but between different devices you can be surprised by how long it takes.) The time required mostly depends on having access to such a partition or device. Make sure that during the moving of files the machine will not be rebooted and your moving process will not be interrupted.
For example:
# df -k /source_directory Filesystem kbytes used avail capacity Mounted on /dev/dsk/c0t0d0s0 34750583 28174655 6228423 82% /source_directory # df -k /destination_directory Filesystem kbytes used avail capacity Mounted on /dev/md/dsk/d30 34750583 28174655 6228423 82% /destination_directoryIn the previous case the /source_directory is the directory created on the local disk (root partition) and the /destination_directory is the directory created on the metadevice. So the time would not be the same as it would be on the same partition.
Make sure that the destination and source directory have the same block structure. If not, avoid using cp or mv commands. To check this you can create the same text file on each device and run the du -ks command on each file.
For example:
# du -ks ./example.txt 4 ./example.txt # du -ks /tmp/example.txt 8 /tmp/example.txtBut the diff or sdiff -s commands show no differences.
Owner, Groups, Permissions
Make sure that owner, group, permissions, and any other file information are preserved. Some users or services might lose access to such data in the new location, and you would not be aware of that. Sometimes the service could be a critical part of the system.
Summary and Some Issues
Instead of using mv or cp commands to move or copy large amounts of data, consider the following procedure:
- Make sure that none of the caveats mentioned previously would apply.
- Verify disk spaces.
For example:
# df -k <directory>
where <directory> - source directory# df -k <directory>
where <directory> - destination directory- Copy data to the destination using commands such as cpio (recommended), tar, rsync, ufsdump, or ufsrestore.
Example:
Let the source directory be /source, and let the destination directory be /destination.
# cd /source # cd .. # find ./source -depth -print | cpio -cvo> /destination/source_data.cpio # cd /destination # cpio -icvmdI ./source_data.cpio # rm -rf ./source_data.cpioThis -c option is important in case the data is copied among different types of machines. This option provides read or write header information in ASCII character form for portability. There are no UID or GID restrictions associated with this header format. Use this option between SVR4-based machines, or use the -H odc option between unknown machines. The -c option implies the use of expanded device numbers, which are only supported on SVR4-based systems. Use the -H odc option when you are transferring files between the SunOS 4 or Interactive UNIX and the Solaris 2.6 OS or compatible versions.
The procedure above first creates a file in the /destination directory that contains all the data packed via the cpio command and then unpacks this file in the destination.
For more information, see the manual pages for the cpio command and other commands if needed.
Also refer to:
- System Administration Guide (for the version of your installed system)
- GNU cpio
- Compare data in the source directory and in the destination directory via commands such as sdiff -s, diff, du -ks, find, cmp, and dircmp.
Example:
Let the source directory be /source, and let the destination directory be /destination.
# cd /source # cd .. # dircmp -s ./source ./destination- If you intend to move data instead of copying, and you are completely sure that all data in the new location is correct, just remove all data in the source location or back it up somewhere else.
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Abstract: This article discusses the problems that can occur when you move and copy files and directories, and the author also offers solutions.
Contents:
Introduction
You could say, "This is not a problem for me because I can copy files with the cp or cp -r commands or move files with the mv command." However, sometimes you can break something and lose data.
I recommend you avoid such solutions as the cp or mv commands when you need to copy or move big files, large numbers of files, or large amounts of data. Also, avoid using commands such as cp or mv when you need to keep the same owner, group, permissions, and all the other information about the data.
Google matched content |
cp - Linux Command - Unix Command
Linux Guide-Getting Help - Wikibooks, collection of open-content textbooks
cp [OPTION]... [-T] SOURCE DEST
cp [OPTION]... SOURCE... DIRECTORY
cp [OPTION]... -t DIRECTORY SOURCE...Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.
Mandatory arguments to long options are mandatory for short options too.
- -a, --archive
- same as -dpR
- --backup[=CONTROL]
- make a backup of each existing destination file
- -b
- like --backup but does not accept an argument
- --copy-contents
- copy contents of special files when recursive
- -d
- same as --no-dereference --preserve=link
- -f, --force
- if an existing destination file cannot be opened, remove it and try again
- -i, --interactive
- prompt before overwrite
- -H
- follow command-line symbolic links
- -l, --link
- link files instead of copying
- -L, --dereference
- always follow symbolic links
- -P, --no-dereference
- never follow symbolic links
- -p
- same as --preserve=mode,ownership,timestamps
- --preserve[=ATTR_LIST]
- preserve the specified attributes (default: mode,ownership,timestamps) and security contexts, if possible additional attributes: links, all
- --no-preserve=ATTR_LIST
- don't preserve the specified attributes
- --parents
- use full source file name under DIRECTORY
- -R, -r, --recursive
- copy directories recursively
- --remove-destination
- remove each existing destination file before attempting to open it (contrast with --force)
- --sparse=WHEN
- control creation of sparse files
- --strip-trailing-slashes remove any trailing slashes from each SOURCE
- argument
- -s, --symbolic-link
- make symbolic links instead of copying
- -S, --suffix=SUFFIX
- override the usual backup suffix
- -t, --target-directory=DIRECTORY
- copy all SOURCE arguments into DIRECTORY
- -T, --no-target-directory
- treat DEST as a normal file
- -u, --update
- copy only when the SOURCE file is newer than the destination file or when the destination file is missing
- -v, --verbose
- explain what is being done
- -x, --one-file-system
- stay on this file system
- --help
- display this help and exit
- -Z, --context=CONTEXT
- set security context of copy to CONTEXT
- --version
- output version information and exit
By default, sparse SOURCE files are detected by a crude heuristic and the corresponding DEST file is made sparse as well. That is the behavior selected by --sparse=auto. Specify --sparse=always to create a sparse DEST file whenever the SOURCE file contains a long enough sequence of zero bytes. Use --sparse=never to inhibit creation of sparse files.
The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX. The version control method may be selected via the --backup option or through the VERSION_CONTROL environment variable. Here are the values:
- none, off
- never make backups (even if --backup is given)
- numbered, t
- make numbered backups
- existing, nil
- numbered if numbered backups exist, simple otherwise
- simple, never
- always make simple backups
As a special case, cp makes a backup of SOURCE when the force and backup options are given and SOURCE and DEST are the same name for an existing, regular file.
In the first synopsis form, neither source_file nor target_file are directory files, nor can they have the same name. The cp utility copies the contents of source_file to the destination path named by target_file. If target_file exists, cp overwrites its contents, but the mode (and ACL if applicable), owner, and group associated with it are not changed. The last modification time of target_file and the last access time of source_file are set to the time the copy was made. If target_file does not exist, cp creates a new file named target_file that has the same mode as source_file except that the sticky bit is not set unless the user is super-user. In this case, the owner and group of target_file are those of the user, unless the setgid bit is set on the directory containing the newly created file. If the directory's setgid bit is set, the newly created file has the group of the containing directory rather than of the creating user. If target_file is a link to another file, cp overwrites the link destination with the contents of source_file; the link(s) from target_file remains.
In the second synopsis form, one or more source_files are copied to the directory specified by target. It is an error if any source_file is a file of type directory, if target either does not exist or is not a directory.
In the third synopsis form, one or more directories specified by source_dir are copied to the directory specified by target. Either -r or -R must be specified. For each source_dir, cp copies all files and subdirectories.
OPTIONS
The following options are supported for both /usr/bin/cp and /usr/xpg4/bin/cp:
- -f
- Unlink. If a file descriptor for a destination file cannot be obtained, this option attempts to unlink the destination file and proceed.
- -H
- Takes actions based on the type and contents of the file referenced by any symbolic link specified as a source_file operand.
- -i
- Interactive. cp prompts for confirmation whenever the copy would overwrite an existing target. A y answer means that the copy should proceed. Any other answer prevents cp from overwriting target.
- -L
- Takes actions based on the type and contents of the file referenced by any symbolic link specified as a source_file operand or any symbolic links encountered during traversal of a file hierarchy.
- -P
- Takes actions on any symbolic link specified as a source_file operand or any symbolic link encountered during traversal of a file hierarchy.
- -r
- Recursive. cp copies the directory and all its files, including any subdirectories and their files to target. Unless the -H, -L, or -P option is specified, the -L option is used as the default mode.
- -R
- Same as -r, except pipes are replicated, not read from.
- -@
- Preserves extended attributes. cp attempts to copy all of the source file's extended attributes along with the file data to the destination file.
Specifying more than one of the mutually-exclusive options -H, -L, and -P is not considered an error. The last option specified determines the behavior of the utility.
/usr/bin/cp
The following option is supported for /usr/bin/cp only:
- -p
- Preserve. cp duplicates not only the contents of source_file, but also preserves the owner and group id, permission modes, modification and access time, ACLs, and extended attributes, if applicable. The command can fail if ACLs are copied to a file system without appropriate support. The command does not fail if unable to preserve extended attributes, modification and access time, or permission modes. If unable to preserve owner and group id, cp does not fail, and it clearsS_ISUID and S_ISGID bits in the target. cp prints a diagnostic message to stderr and return a non-zero exit status if unable to clear these bits.
In order to preserve the owner and group id, permission modes, and modification and access times, users must have the appropriate file access permissions. This includes being superuser or the same owner id as the destination file.
When both -p and -@ options are specified, the -p option determines the behavior. However, the command can fail if unable to preserve extended attributes.
/usr/xpg4/bin/cp
The following option is supported for /usr/xpg4/bin/cp only:
- -p
- Preserve. cp duplicates not only the contents of source_file, but also preserves the owner and group id, permission modes, modification and access time, ACLs, and extended attributes, if applicable. The command can fail if ACLs are copied to a file system without appropriate support. The command does not fail if unable to preserve extended attributes. If unable to duplicate the modification and access time or the permission modes, cp prints a diagnostic message to stderr and return a non-zero exit status. If unable to preserve owner and group id, cp does not fail, and it clearsS_ISUID and S_ISGID bits in the target. cp prints a diagnostic message to stderr and return a non-zero exit status if unable to clear these bits.
In order to preserve the owner and group id, permission modes, and modification and access times, users must have the appropriate file access permissions. This includes being superuser or the same owner id as the destination file.
When both -p and -@ options are specified, the last specified -p or -@ option determines the behavior.
OPERANDS
The following operands are supported:
- source_file
- A pathname of a regular file to be copied.
- source_dir
- A pathname of a directory to be copied.
- target_file
- A pathname of an existing or non-existing file, used for the output when a single file is copied.
- target
- A pathname of a directory to contain the copied files.
USAGE
See largefile(5) for the description of the behavior of cp when encountering files greater than or equal to 2 Gbyte ( 231 bytes).
EXAMPLES
Example 1 Copying a File
The following example copies a file:
example% cp goodies goodies.old example% ls goodies* goodies goodies.old
Example 2 Copying a List of Files
The following example copies a list of files to a destination directory:
example% cp ~/src/* /tmp
Example 3 Copying a Directory
The following example copies a directory, first to a new, and then to an existing destination directory
example% ls ~/bkup /usr/example/fred/bkup not found example% cp -r ~/src ~/bkup example% ls -R ~/bkup x.c y.c z.sh example% cp -r ~/src ~/bkup example% ls -R ~/bkup src x.c y.c z.sh src: x.c y.c z.s
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of cp: LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES, and NLSPATH.
EXIT STATUS
The following exit values are returned:
- 0
- All files were copied successfully.
- >0
- An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
/usr/bin/cp
ATTRIBUTE TYPE ATTRIBUTE VALUE Availability SUNWcsu CSI Enabled Interface Stability Stable
/usr/xpg4/bin/cp
ATTRIBUTE TYPE ATTRIBUTE VALUE Availability SUNWxcu4 CSI Enabled Interface Stability Standard
SEE ALSO
chmod(1), chown(1), setfacl(1), utime(2), attributes(5), environ(5), fsattr(5), largefile(5), standards(5)
NOTES
SunOS 5.10 Last Revised 13 May 2004
The permission modes of the source file are preserved in the copy.
A -- permits the user to mark the end of any command line options explicitly, thus allowing cp to recognize filename arguments that begin with a -.
O'Relly/Linux Command Directory cp
This directory of Linux commands is from Linux in a Nutshell, 5th Edition.
Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.
Buy it now, or read it online on Safari Bookshelf.
cp
cp [options] file1 file2 cp [options] files directory
Copy file1 to file2, or copy one or more files to the same names under directory. If the destination is an existing file, the file is overwritten; if the destination is an existing directory, the file is copied into the directory (the directory is not overwritten).
Options
-a, --archive Preserve attributes of original files where possible. The same as -dpr.
-b, --backup Back up files that would otherwise be overwritten.
-d, --no-dereference Do not dereference symbolic links; preserve hard-link relationships between source and copy.
-f, --force Remove existing files in the destination.
-i, --interactive Prompt before overwriting destination files. On most systems, this flag is turned off by default except for the root user, who is normally prompted before overwriting files.
-l, --link Make hard links, not copies, of nondirectories.
-p, --preserve Preserve all information, including owner, group, permissions, and timestamps.
-P, --parents Preserve intermediate directories in source. The last argument must be the name of an existing directory. For example, the command:
cp --parents jphekman/book/ch1 newdir
copies the file jphekman/book/ch1 to the file newdir/jphekman/book/ch1, creating intermediate directories as necessary.
-r, -R, --recursive Copy directories recursively.
-S backup-suffix, --suffix=backup-suffix Set suffix to be appended to backup files. This may also be set with the SIMPLE_BACKUP_SUFFIX environment variable. The default is ~. You need to explicitly include a period if you want one before the suffix (for example, specify .bak, not bak).
-s, --symbolic-link Make symbolic links instead of copying. Source filenames must be absolute.
--sparse=[always|auto|never] Handle files that have "holes" (are defined as a certain size but have less data). always creates a sparse file, auto creates one if the input file is sparse, and never creates a non-sparse file without holes.
-u, --update Do not copy a file to an existing destination with the same or newer modification time.
-v, --verbose Before copying, print the name of each file.
-V type, --version-control=type Set the type of backups made. You may also use the VERSION_CONTROL environment variable. The default is existing. Valid arguments are:
t, numbered Always make numbered backups.
nil, existing Make numbered backups of files that already have them; otherwise, make simple backups.
never, simple Always make simple backups.
-x, --one-file-system Ignore subdirectories on other filesystems.
Example
Copy the contents of the guest directory recursively into the /archives/guest/ directory, and display a message for each file copied:
cd /archives && cp -av /home/guest guest
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