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Copying Files – cp Command

cp Command Structure : cp [OPTIONS] SOURCE DESTINATION

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Option Meaning Example
-v Verbose — shows what is being copied cp -v a.txt backup/
-i Interactive — ask before overwrite cp -i report.txt /tmp/
-r or -R Recursive — copy directories cp -r Project/ BackupProject/
-f Force overwrite without asking cp -f data.csv /tmp/
-p Preserve permissions, ownership, timestamps cp -p script.sh /backup/

Copying Files – dd Command

The dd command is used to copy data bit-by-bit. It can copy:

  • Files
  • Disks
  • Partitions
  • ISO images
  • Bootable media

It is more powerful (and dangerous) than cp because it writes raw data.

Structure: 

dd [OPTIONS] OPERAND #Command Structure
dd if=SOURCE of=DESTINATION [options] #Common Structure

Common Options

Option Meaning
if= Input file (source)
of= Output file (destination)
bs= Block size (amount of data copied at once)
count= Number of blocks to copy
status= Show progress (e.g., status=progress)

Example: 

dd if=file1.txt of=file2.txt                             # Copy a file block-by-block
sudo dd if=linux.iso of=/dev/sdb bs=4M status=progress   # Create a bootable USB from ISO
sudo dd if=/dev/sda of=/backup/sda.img status=progress   # Backup an entire disk
dd if=/dev/zero of=emptyfile.bin bs=1M count=10          # Create a 10 MB file filled with zeros
dd if=/dev/zero of=/tmp/swapex bs=1M count=50           # Create a 50 MB swap file

Important: Permissions Needed for Copying

To successfully copy a file:

Permissions Required

  • Must have write (w) and execute (x) permissions on:

  • The source directory

  • The destination directory

usually have the needed permissions in:

  • home directory (~/)
  • Temporary directory (/tmp)