## Check User
### Instructions
In this exercise you will make a script `check-user.sh` that will take 2 arguments and return information about the selected user, always ended by a new line.
The first argument will be a flag defining the behavior of the script:
- `-e` : check if the user exists, returns `yes` or `no` appropriately.
- `-i` : returns information about the user.
The second argument will be the name of the checked user.
> The information about the user will be formatted in the same way it appears in `/etc/passwd`.
### Usage
```console
$ ./check-user.sh -e root
yes
$ ./check-user.sh -i root
root:x:0:0:root:/root:/bin/bash
$ ./check-user.sh -e unknown
no
$ ./check-user.sh -i unknown
$
```
> Your results may appear slightly different.
### Error handling
All errors will print a specific message on **stderr** (ending with a newline) and returns a specific non-zero value:
- Wrong number of arguments: `"Error: expect 2 arguments"` , exit with `1` .
- First argument different from `-e` or `-i` : `"Error: unknown flag"` , exit with `1` .
### Hints
- `getent` is a command to get entries from a database. `passwd` is the database where information about users is stored.
- `getent passwd` will give you the list of all users.
- `getent passwd <username>` will give you information about a specific user.
- If the user doesn't exists `getent` returns an empty string, use this at your advantage for `-e` flag.
> `man getent` will provide extensive documentation about this command.
### Resources
> [List Linux users](https://linuxize.com/post/how-to-list-users-in-linux/)
