One linux command every day (8): cp command

One linux command every day (8): cp command link: One linux command every day (1): ls command http://www.2cto.com/ OS /210210/163049.html#linuxlinuxcommand every day (2): cd command quit (..
One linux command every day (8): cp command link: One linux command every day (1): ls command http://www.2cto.com/os/201210/163049.html ; One linux command every day (2): cd command http://www.2cto.com/os/201210/163050.html ; One linux command every day (3): pwd command http://www.2cto.com/os/201210/163462.html ; One linux command every day (4): mkdir command http://www.2cto.com/os/201210/163463.html ; One linux command every day (5): rm command http://www.2cto.com/os/201210/163662.html ; One linux command (6) every day: rmdir command http://www.2cto.com/os/201210/164017.html ; One linux command (7) every day: mv command http://www.2cto.com/os/201210/164247.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: www.2cto.com usage: cp [option]... [-T] source target or: cp [option]... source... directory or: cp [option]... -t directory source... 2. command: copy the source file to the target file, or copy multiple source files to the target directory. Www.2cto.com 3. command parameter:-, -- archive is equal to-dR -- preserve = all -- backup [= CONTROL creates a backup for each existing target file-B is similar to -- backup but does not accept the parameter -- copy-contents in recursive processing is copy the content of a special file-d equals to -- no-dereference -- preserve = links-f, -- force: if the target file cannot be opened, remove it and try again (this option is not required when the-n option exists)-I, -- interactive overwrite the previous query (invalidate the previous-n option)-H follows the command line symbolic link-l in the source file, -- link file without copying-L, -- dereference always follows the symbolic link-n, -- no-clobber does not overwrite existing files (make the previous-I option invalid)-P, -- no-dereference does not follow the symbolic link in the source file -P equals to -- preserve = mode, ownership, timestamp -- preserve [= attribute list to keep the specified attribute (default: mode, ownership, timestamp). if it is possible to keep the additional attribute: environment, link, xattr, etc.-R,-r, -- recursive copy directory and all the projects in the directory www.2cto.com 4. command instance: instance 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. logdrwxr-xr-x 6 root 4096 10-27 0:58 scfdrwxrwxrwx 2 root 4096 10-28 test3drwxr-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 -- r -- 1 root 0 10-28 log5-2.log-rw-r -- r -- 1 root 0 10-28 log5-3.log-rw-r -- r -- 1 root 0 10-28 log. log description: 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. Www.2cto.com instance 2: If the target file exists, you will be asked whether to overwrite the command: cp log. log test5 output: [root @ localhost test] # cp log. log test5cp: whether to overwrite "test5/log. log "? N [root @ localhost test] # cp-a log. log test5cp: 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 -- r -- 1 root root 0 10-28 log5-2.log-rw-r -- r -- 1 root 0 10-28 log5-3.log-rw-r -- r -- 1 root 0 10-28 log. log description: 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. Www.2cto.com instance 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. logdrwxr-xr-x 6 root 4096 10-27 0:58 scfdrwxrwxrwx 2 root 4096 10-28 test3drwxr-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 -- r -- 1 ro Ot root 0 10-28 log5-2.log-rw-r -- r -- 1 root 0 10-28 log5-3.log-rw-r -- r -- 1 root 0 10-28 log. logdrwxrwxrwx 2 root 4096 10-28 test3 target directory does not exist: [root @ localhost test] # cp-a test3 test4 [root @ localhost test] # ll-rw-r -- 1 root 0 10-28 log. logdrwxr-xr-x 6 root 4096 10-27 scfdrwxrwxrwx 2 root 4096 10-28 test3drwxrwxrwx 2 root 40 96 10-28 test4drwxr-xr-x 3 root 4096 10-28 test5 [root @ localhost test] # Note: The results of the existence of the target directory is not the same. If the target directory exists, the entire source directory is copied to the target directory. Www.2cto.com instance 4: The Copied log. log to create a link file log_link.log command: cp-s log. log log_link.log output: [root @ localhost test] # cp-s log. log log_link.log [root @ localhost test] # lllrwxrwxrwx 1 root 7 10-28 log_link.log-> log. log-rw-r -- 1 root 0 10-28 log. logdrwxr-xr-x 6 root 4096 10-27 0:58 scfdrwxrwxrwx 2 root 4096 10-28 test3drwxrwxrwx 2 root 4096 10-28 test4drwxr-xr -X 3 root 4096 10-28 test5 note: The log_link.log is caused by the-s parameter and creates a "shortcut 』, so you will see at the far right of the file, it will show where the file is connected!