id: z5NH94vk86m35HxJ
createdBy: 6cb8dad0xmtGH1
dateCreated: 1713192447954
name: 'Lab-Linux: C-Programming'
meta:
logo: >-
https://raw.githubusercontent.com/edrys-labs/lab-linux/main/media/c.jpg
description: >-
Explore the basics of C programming and GCC compiler usage with our
step-by-step tutorial designed for beginners. Start by creating a simple
"Hello, World!" program, then enhance it to interact with users by asking
for their name and providing a personalized greeting. Additionally, learn
how to identify and fix a common coding error through a detailed explanation
of GCC error messages. This tutorial provides a practical introduction to
writing, compiling, and debugging simple C programs, perfect for young
learners and newcomers to programming.
selfAssign: true
defaultNumberOfRooms: 0
members:
teacher: []
student: []
modules:
- url: >-
https://raw.githubusercontent.com/edrys-labs/module-markdown-it/2.0.0/index.html
config: |-
# Welcome to Lab-Linux: C-Programming
C is a powerful computer programming language that lets you tell a computer what to do.
It's a bit like writing a recipe that the computer follows to complete tasks.
People use C to create software applications, help gadgets like your microwave work, or even make video games!
Here’s why C is cool for learning:
1. **Simple to start**:
Even though it's powerful, C isn't very complicated to learn.
It has a small number of commands to remember, which are like the basic building blocks for more complex programs.
2. **Everywhere in technology**:
Many of the electronics around us, like robots and smartphones, use C to function.
Learning C can help you understand more about how these things work.
3. **A great foundation**:
Once you understand C, learning other languages like Python, Java, or C++ becomes easier because many programming languages are based on C.
Imagine C as the language that bridges your instructions with the computer’s actions.
By learning C, you're learning how to speak directly to computers, and that’s a super useful skill to have!
__Visit a station by clicking onto it and then explore the terminal ;-)__
studentConfig: ''
teacherConfig: >-
## Welcome for Teachers
> This can be used as a base laboratory to create further and more
elaborate labs with [edrys-Lite](https://edrys-labs.github.io).
> You are currently in the Lobby. If there is a station available you can
switch to it and try out the terminal.
> Otherwise, if you are in teacher-mode you can share a lab by clicking
onto `setting` >> `station` and then by clicking the presented link,
> which is the same as the current link, but only with the word `station`
instead of `classroom`.
stationConfig: ''
showInCustom: lobby
width: full
height: huge
- url: https://edrys-labs.github.io/module-editor/index.html
config:
editorText: Starting text in editor...
runCommand: execute
language: cpp
theme: light
studentConfig: ''
teacherConfig: ''
stationConfig: ''
showInCustom: station
width: full
height: medium
- url: >-
https://raw.githubusercontent.com/edrys-labs/module-markdown-it/2.0.0/index.html
config: >-
# Welcome to the Station
## C-Programming Tutorial
Copy the following program into the editor
```cpp
#include <stdio.h>
int main() {
printf("Hello, world!");
return 0;
}
```
... and execute it ...
### Handling inputs
Modify the program to look like this:
``` c
#include <stdio.h>
int main() {
// This array stores the name
char name[50];
printf("Enter your name: ");
// Read user input into the 'name' variable
scanf("%s", name);
printf("Hello, %s!\n", name);
return 0;
}
```
Compile and Run Your Modified Program...
Follow the prompt to enter your name, and you should see a personalized
greeting.
### Introduce an Error
Now, let's introduce a common error. Suppose we accidentally misspell the
`printf` function.
1. **Modify your program** again:
```c
#include <stdio.h>
int main() {
char name[50];
printf("Enter your name: ");
scanf("%s", name)
// Error: 'print' is used instead of 'printf'
print("Hello, %s!\n", name);
return 0;
}
```
2. Try to compile it again with.
### Identifying and Fixing the Error
When you try to compile this incorrect program, GCC will generate an error
message. Here's what you might see in your terminal:
``` bash
main.c:7:21: error: expected ‘;’ before ‘print’
7 | scanf("%s", name)
| ^
| ;
8 | // Error: 'print' is used instead of 'printf'
9 | print("Hello, %s!\n", name);
| ~~~~~
```
**What went wrong?**
- **Implicit declaration of function ‘print’**: This means GCC doesn't
recognize `print` as a valid function. This is because there is no
standard function called `print` in C; it should be `printf`.
- **Expected ‘;’ before ‘(’ token**: This error appears because GCC is
confused by the unexpected function name and mishandles the syntax of C.
**How to fix it:**
- Replace `print` with `printf`.
- Make sure every function call ends with a semicolon (`;`).
After correcting the error, save your file and compile it again. When you
run it, it should work as expected, asking for your name and greeting you
correctly.
This process of identifying errors from compiler messages and resolving
them is crucial in learning to program in C or any programming language.
studentConfig: ''
teacherConfig: ''
stationConfig: >-
## Instructions for Station-Sharing
You are currently responsible for sharing a station of this lab.
You have multiple options to share a or your terminal.
Therefor we use the pyxtermjs - terminal server from:
https://github.com/edrys-labs/module-pyxtermjs
### Using Docker
If you haven't done it so far, install
[docker](https://docs.docker.com/engine/install/).
Or, follow one of the instruction-videos for your system:
<details>
<summary>Install Docker on Linux</summary>
<iframe
style="width: 100%; aspect-ratio: 16 / 9"
src="https://www.youtube.com/embed/cqbh-RneBlk?si=juvUM5d2OSZ28WBv"
title="YouTube video player"
frameborder="0"
allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"
referrerpolicy="strict-origin-when-cross-origin"
allowfullscreen></iframe>
</details>
<details>
<summary>Install Docker on Windows</summary>
<iframe
style="width: 100%; aspect-ratio: 16 / 9"
src="https://www.youtube.com/embed/WDEdRmTCSs8?si=X0agStn1akNcZLGu"
title="YouTube video player"
frameborder="0"
allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"
referrerpolicy="strict-origin-when-cross-origin"
allowfullscreen></iframe>
</details>
<details>
<summary>Install Docker on MacOS</summary>
<iframe
style="width: 100%; aspect-ratio: 16 / 9"
src="https://www.youtube.com/embed/-EXlfSsP49A?si=OZ_l4_2hDKb6ULQ_"
title="YouTube video player"
frameborder="0"
allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"
referrerpolicy="strict-origin-when-cross-origin"
allowfullscreen></iframe>
</details>
Then the only thing that is required is to run the following command:
```bash
docker run -it -p 5000:5000 crosslab/edrys_pyxtermjs_development:latest
```
This will download the pyxtermjs terminal-server from docker-hub and run
it in a secure environment.
It contains support for:
- `clojure`
- `g++`
- `gcc`
- `golang`
- `haskell`
- `java`
- `lua`
- `mono`
- `nodejs`
- `python 3`
- `r`
- `rustc`
### Using Python
You can also share your terminal directly via Python, visit the follwing
project
https://github.com/edrys-labs/module-pyxtermjs
... the easiest way is to perform the following steps:
``` bash
# 1. clone the repository or download the folder manually
git clone https://github.com/edrys-labs/module-pyxtermjs
# 2. install all required sources
pip3 install -r requirements.txt
# 3. run the terminal-server
python3 -m pyxtermjs --cors True --command bash --port 5000
```
showInCustom: station
width: half
height: huge
- url: https://edrys-labs.github.io/module-pyxtermjs/index.html
config: ''
studentConfig: ''
teacherConfig: ''
stationConfig:
server: http://localhost:5000/pty
execute: execute
script: |-
echo $CODE | base64 --decode > main.c
gcc main.c & ./a.out
enable:
teacher: true
student: true
showInCustom: station
width: full
height: medium