cp Study Notes

cp (copy)

It copies:

  • files
  • directories
  • symbolic links
  • special files (optionally)

The copied object becomes independent from the original unless linking options are used.

SECTION 1 - Copying Files

Copy one file:

cp file1.txt file2.txt

This creates file2.txt copy, with the same contents as file1.txt. If file2.txt exists, it is overwritten.

Multiple files:

cp file1 file2 file3 directory/

Copies all files into directory/

-t

Target Directory Syntax:

cp -t directory file1 file2

Equivalent to:

cp file1 file2 directory/

Useful in scripts.

SECTION 2 - Copying Directories

-r, -R, --recursive

Needed to copy directories recursively.

cp -R dir1/ dir2/

-r and -R GNU systems treat them similarly.

  • -R standard recursive
  • -r older, less portable

SECTION 3 - Archive Mode

-a, --archive

Preserve as much as possible of the structure and attributes of the original files in the copy (but do not attempt to preserve internal directory structure)

Equivalent to -dR --preserve=all with the reduced diagnostics.

cp -a source dest

It preserves:

  • permissions
  • ownership
  • timestamps
  • symlinks
  • hard links
  • xattrs
  • SELinux context

SECTION 4 - Symbolic Links

SECTION 5 - Hard Links and Symbolic Links

SECTION 6 - Overwriting Behavior

-i, --interactive

Ask before overwrite.

cp -i file.txt backup/

Prompt:

overwrite 'backup/file.txt'?

-n, --no-clobber

Never overwrite.

cp -n file.txt backup/

Silently skips existing files.

-f, --force

Force overwrite.

cp -f file.txt backup/

Removes destination if necessary.

--remove-destination

Remove destination before writing.

Different from -f.

Useful for replacing special files/symlinks safely.

SECTION 7 - Preserving Attributes

-p

Preserve metadata.

cp -p file backup

--preserve=...

Fine-grained control.

cp --preserve=mode,ownership,timestamps file backup

Preserve Options:

Attribute Meaning
mode permissions
ownership owner/group
timestamps atime/mtime
links hard links
context SELinux
xattr extended attributes
all preserve everything

--no-preserve

Disable preservation selectively.

cp -a --no-preserve=ownership src dst

SECTION 8 - Sparse Files

SECTION 9 - Reflinks (Copy-on-Write)

SECTION 10 - Recursive Filesystem Behavior

SECTION 11 - --parents

SECTION 12 - Verbose and Debugging

-v

Show copied files. Output:

'file' -> 'backup/file'

--debug

Explain copy operations in detail.

Implies -v.

SECTION 13 - Backup Options

-b

Create backups before overwrite.

-S

Custom backup suffix.

cp -b -S .bak file backup/

Creates:

file.bak

SECTION 14 - Dangerous Option

SECTION 15 - SELinux Context

SECTION 17 - Update Mode