# Linux / Unix

### Setup SSH Tunnel

```
// use -p only if the ssh port is different to the default 22
ssh -i ~/.ssh/id_rsa_XXX -p 4422 -L 8080:localhost:8080 User@ServerOrIp
```

### How to Change Hostname on Ubuntu 18.04

```
sudo hostnamectl set-hostname linuxize
```

### Add a network interface alias

{% tabs %}
{% tab title="Linux" %}

```
sudo ifconfig lo:0 10.254.254.254 netmask 255.255.255.0 up
```

{% endtab %}

{% tab title="MacOS" %}

```
sudo ifconfig lo0 alias 10.254.254.254
```

{% endtab %}
{% endtabs %}

### How to count all files extension

```
find . -type f | sed -n 's/..*\.//p' | sort | uniq -c
```

### Grep in file content which is in zip archive 

```
unzip -p archive.zip filenam* | grep search_str
```


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