Cp command, cp command

Cp command (conversion), cp command

Original article: http://www.cnblogs.com/peida/archive/2012/10/29/2744185.html

The cp command is used to copy files or directories. It is one of the most common commands in Linux. In general, shell sets an alias. When copying a file under the command line, if the target file already exists, it will ask whether to overwrite the file, whether or not you use the-I parameter. However, if the cp is executed in a shell script, if the-I parameter is not displayed, the system does not ask whether to overwrite it. This indicates that the command line and shell script are executed differently.

1. Command Format:

Usage:

Cp [Option]... [-T] source objective

Or: cp [Option]... source... directory

Or: cp [Option]...-t directory source...

2. command functions:

Copy the source file to the target file, or copy multiple source files to the target directory.

3. command parameters:

-A, -- archive equals to-dR -- preserve = all

-- Backup [= CONTROL creates a backup for each existing target file

-B is similar to -- backup but does not accept parameters

-- Copy-contents: In recursive processing, copying special file content

-D equals -- no-dereference -- preserve = links

-F, -- force: if the target file cannot be opened, remove it and try again (when-n Option

This option does not need to be selected if it exists)

-I, -- interactive overwrite the previous query (invalidate the previous-n option)

-H follows the command line symbolic link in the source file

-L, -- link file without copying

-L, -- dereference always follows the Symbolic Link

-N, -- no-clobber do not overwrite existing files (invalidate the previous-I option)

-P, -- no-dereference does not follow the symbolic link in the source file

-P equals to -- preserve = mode, ownership, timestamp

-- Preserve [= the attribute list retains the specified attribute (default: mode, ownership, timestamp). If

Additional attributes may be maintained: environment, Link, xattr, etc.

-R,-r, -- recursive: copy the Directory and all projects in the directory

4. Command instance:

Example 1: copy a single file to the target directory. The file does not exist in the target file.

Command:

Cp log. log test5

Output:

[Root @ localhost test] # cp log. log test5

[Root @ localhost test] # ll

-Rw-r -- 1 root 0 10-28 log. log

Drwxr-xr-x 6 root 4096 10-27 0scf

Drwxrwxrwx 2 root 4096 10-28 test3

Drwxr-xr-x 2 root 4096 10-28 test5

[Root @ localhost test] # cd test5

[Root @ localhost test5] # ll

-Rw-r -- 1 root 0 10-28 log5-1.log

-Rw-r -- 1 root 0 10-28 log5-2.log

-Rw-r -- 1 root 0 10-28 log5-3.log

-Rw-r -- 1 root 0 10-28 14:53 log. log

Note:

When the-a parameter is not included, the time of the two files is different. When the-a parameter is included, the time of the two files is the same.

 

Example 2: If the target file exists, you will be asked if it is overwritten.

Command:

Cp log. log test5

Output:

[Root @ localhost test] # cp log. log test5

Cp: overwrite "test5/log. log "? N

[Root @ localhost test] # cp-a log. log test5

Cp: overwrite "test5/log. log "? Y

[Root @ localhost test] # cd test5/

[Root @ localhost test5] # ll

-Rw-r -- 1 root 0 10-28 log5-1.log

-Rw-r -- 1 root 0 10-28 log5-2.log

-Rw-r -- 1 root 0 10-28 log5-3.log

-Rw-r -- 1 root 0 10-28 log. log

Note:

If the target file exists, you will be asked whether to overwrite it. This is because cp is the alias of cp-I. When the target file exists, even if the-f flag is added, the system will also ask whether to overwrite the file.

 

Example 3: copy the entire directory

Command:

Output:

When the target directory exists:

[Root @ localhost test] # cp-a test3 test5

[Root @ localhost test] # ll

-Rw-r -- 1 root 0 10-28 log. log

Drwxr-xr-x 6 root 4096 10-27 0scf

Drwxrwxrwx 2 root 4096 10-28 test3

Drwxr-xr-x 3 root 4096 10-28 test5

[Root @ localhost test] # cd test5/

[Root @ localhost test5] # ll

-Rw-r -- 1 root 0 10-28 log5-1.log

-Rw-r -- 1 root 0 10-28 log5-2.log

-Rw-r -- 1 root 0 10-28 log5-3.log

-Rw-r -- 1 root 0 10-28 log. log

Drwxrwxrwx 2 root 4096 10-28 test3

The target directory does not exist:

[Root @ localhost test] # cp-a test3 test4

[Root @ localhost test] # ll

-Rw-r -- 1 root 0 10-28 log. log

Drwxr-xr-x 6 root 4096 10-27 0scf

Drwxrwxrwx 2 root 4096 10-28 test3

Drwxrwxrwx 2 root 4096 10-28 test4

Drwxr-xr-x 3 root 4096 10-28 test5

[Root @ localhost test] #

Note:

Note that the results of the existence of the target directory are different. If the target directory exists, the entire source directory is copied to the target directory.

 

Example 4: Create a log_link.log link for the copied log. log

Command:

Cp-s log. log log_link.log

Output:

[Root @ localhost test] # cp-s log. log log_link.log

[Root @ localhost test] # ll

Lrwxrwxrwx 1 root 7 10-28 log_link.log-> log. log

-Rw-r -- 1 root 0 10-28 log. log

Drwxr-xr-x 6 root 4096 10-27 0scf

Drwxrwxrwx 2 root 4096 10-28 test3

Drwxrwxrwx 2 root 4096 10-28 test4

Drwxr-xr-x 3 root 4096 10-28 test5

 

Note:

The log_link.log is caused by the-s parameter and is created with a "shortcut". Therefore, you can see that it is on the rightmost side of the file, the location where the file is linked is displayed!