SCP for file transfer in Linux CLI - Step-by-Step Execution

Concept Flow - SCP for file transfer

Start SCP command

↓

Check source file exists

↓

Establish SSH connection

↓

Transfer file data

↓

Write file on destination

↓

Close connection

↓

End with success or error

This flow shows how SCP checks the source, connects securely, transfers the file, and finishes.

Execution Sample

Linux CLI

scp /home/user/file.txt user@remote:/home/user/

This command copies file.txt from local to remote user's home directory.

Execution Table

Step	Action	Evaluation	Result
1	Start SCP command	scp /home/user/file.txt user@remote:/home/user/	Command initiated
2	Check source file	/home/user/file.txt exists?	Yes, file found
3	Establish SSH connection	Connect to user@remote	Connection successful
4	Transfer file data	Send file.txt bytes	Data sent successfully
5	Write file on destination	Write to /home/user/file.txt	File written successfully
6	Close connection	End SSH session	Connection closed
7	End	Transfer complete	Success

💡 Transfer ends after file is written and connection closes successfully

Variable Tracker

Variable	Start	After Step 2	After Step 4	Final
source_file	/home/user/file.txt	Exists	Data read	Transfer complete
ssh_connection	None	None	Established	Closed
transfer_status	Not started	Not started	In progress	Success

Key Moments - 3 Insights

What happens if the source file does not exist?

SCP stops at Step 2 with an error because it cannot find the file to send.

Why is SSH connection important in SCP?

At Step 3, SCP uses SSH to securely connect and transfer files safely.

When does SCP close the connection?

After the file is fully transferred and written (Step 6), SCP closes the SSH connection.

Visual Quiz - 3 Questions

Look at the execution table, at which step is the file data actually sent?

A Step 5

B Step 2

C Step 4

D Step 6

💡 Hint

Check the 'Action' column for when data transfer happens.

At which step does SCP check if the source file exists?

A Step 2

B Step 1

C Step 3

D Step 5

💡 Hint

Look for the step mentioning source file check.

If the SSH connection fails, which step would SCP not reach?

A Step 3

B Step 4

C Step 6

D Step 7

💡 Hint

Without connection, data transfer cannot start.

Concept Snapshot

scp [source] [user@host:destination]

- Copies files securely over SSH
- Checks source file before transfer
- Establishes SSH connection
- Transfers file data
- Writes file on remote
- Closes connection after transfer

Full Transcript

SCP is a command to copy files securely between computers using SSH. First, it checks if the source file exists locally. Then, it connects to the remote computer using SSH. After connection, it sends the file data over the secure channel. The remote side writes the file to the destination path. Finally, SCP closes the connection and ends with success or error. This process ensures safe and reliable file transfer.