> For the complete documentation index, see [llms.txt](https://www.techwithtyler.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.techwithtyler.dev/operating-systems/linux/cli-tools-cheat-sheet.md).

# CLI Tools Cheat Sheet

## awk

* A tool with similar capabilities to `cat` and `cut` where it can read file contents and customize the output.

{% code lineNumbers="true" %}

```
// Selecting text fields from a file
root@box ~ $ awk '{print $1 ""}' subdomains.txt
blog.techwithtyler.dev
braindump.techwithtyler.dev
techwithtyler.dev
www.techwithtyler.dev
```

{% endcode %}

## cat

* A tool for reading file contents onto standard output (STDOUT).

{% code lineNumbers="true" %}

```sh
// Reading files
root@box ~ $ cat subdomains.txt
blog.techwithtyler.dev 234234234
braindump.techwithtyler.dev 25346536
techwithtyler.dev 43564356743
www.techwithtyler.dev 45776568
```

{% endcode %}

## cut

* A tool for removing sections from each line of files

{% code lineNumbers="true" %}

```
// Selecting text fields from a file
root@box ~ $ cut -f2 -d " " subdomains.txt
234234234
25346536
43564356743
45776568
```

{% endcode %}

```
// Another option, piping output to cut
root@box ~ $ cat subdomains.txt | cut -f2 -d " "
234234234
25346536
43564356743
45776568
```

## export

* Useful to create env vars or updating your $PATH

```sh
# adds a tool to your path
export PATH=$PATH:/opt/aws/bin
```

## find

* More advanced than the `locate` tool.
* It can search based on several attributes e.g., permissions, timestamp, file size, and more.

```
// Finding a file

$ find -name my-*
./a/b/c/d/e/f/g/my-lost-file
```

```
// Finding files owned by root where all users have 'write' permissions

$ find / -type f -group root -perm -a=w 2>/dev/null
/proc/sys/kernel/ns_last_pid
/proc/pressure/io
/proc/pressure/cpu
[SNIP]
```

## locate

* A useful tool for quickly finding files and directories. 
* Install it with: `sudo apt install mlocate`
* It's a local database that gets updated regularly with a cron job but can otherwise be forced to update with: `sudo updatedb`

```
// Finding a file

$ locate my-lost-file
/home/parrot/a/b/c/d/e/f/g/my-lost-file
```

## which

* Searches the `$PATH` environment variable for any executable matching the search.

```
// Checking if python3 is installed 

$ which python3
/usr/bin/python3
```