# SCP File Copy

SCP (Secure Copy Protocol) is a secure file transfer tool based on **SSH**, used for transferring files and directories between a local host and a Quectel Pi L1 / M1 Debian system via encrypted connections. Before using SCP, ensure that the SSH service on the Quectel Pi L1 / M1 is started and that the computer and development board can communicate over the network.

This document was tested in the `q@10.66.84.182` environment. Local upload, remote download, and recursive directory copy all work correctly. In actual use, use the development board's current IP address.

# Common Scenarios

All the following commands are executed in the local command-line terminal.

- Transfer files from the local host to a remote host (local → remote):

```bash
scp /本地/文件.txt username@Quectel-Pi-IP:/目标路径/
```

Example:

```bash
scp ~/test.zip q@10.66.84.182:/home/q/  # 复制到远程主机的home目录
```

- Transfer files between two remote hosts (remote → remote):

```bash
scp user1@host1:/path/to/file user2@host2:/path/to/dest/
```

Example:

```bash
scp alice@server1:/data/report.txt bob@server2:/backups/
```

- Transfer files from a remote host to the local host (remote → local):

```bash
scp username@Quectel-Pi-IP:/远程/文件.txt /本地/路径/
```

Example:

```bash
scp q@10.66.84.182:/home/q/test.log ./downloads/  # 下载远程文件到本地
```

# Recursive Directory Copy

Copy an entire folder (including sub-files and sub-directories):

```bash
scp -r /本地/目录/ username@Quectel-Pi-IP:/目标路径/
```

Example:

```bash
scp -r ~/my_project/ q@10.66.84.182:/home/q/
```