cp : Copying Files

Cp Command:

The cp command lets you copy a file from one location to another on a UNIX machine.
The cp command overwrites an existing destination file if it is with file contents.
Another use of cp is to create a link of a file.

Syntex:

cp [option] source destination

Source – may be source file name, file with path or directory name, directory with path.

Destination – may be destination file name, file with path or destination directory name, and directory with path.

 

Copy a file or directory from source to destination

cp A.txt B.txt

File A.txt is a source file and B.txt is a destination file, both are inside current directory. So it is not required to mention a path if both source and destination exist inside the same directory.

cp  /home/my_doc/a/f.txt  /home/back_up/

(Absolute Path)

Here the source and destination path is mentioned with filename as both exist in different locations. Absolute path is a path which starts from root.

cp  ./F.txt  ./../../back_up/

(Relative path)

Relative path is a path which starts from current directory.

Here .(dot) means current directory and ..(Double dot) means we are moving one step back/up in directory structure as shown in Fig.

Some examples of cp command:

cp *.txt  ./A/B/

here We have to copy all text file (file with extension .txt) inside current directory to the destination directory B which is inside A and A is inside current directory.

QS: Why sometimes it is not possible to copy a file?

When the file to be copied is read protected or the destination directory is write protected, and then it is not possible to copy a file.

QS: How to copy a whole directory structure?

cp –R <path_of_dir/*> <path_of_destination>

Ex: cp –R ./my_dir/* ./dir_bkp/

Qs: How to copy a file without changing its modification time?

cp -p <source> <destination>

Qs: How to create a link using CP command?

cp –l

cp -s

Qs: how to copy only when the source file is newer than the destination and destination file is missing?

cp -u