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https://github.com/asut00/get_next_line
Creating a function that reads a line from a file descriptor in C
https://github.com/asut00/get_next_line
Last synced: 20 days ago
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Creating a function that reads a line from a file descriptor in C
- Host: GitHub
- URL: https://github.com/asut00/get_next_line
- Owner: asut00
- Created: 2024-11-08T17:30:36.000Z (2 months ago)
- Default Branch: main
- Last Pushed: 2024-11-08T18:11:51.000Z (2 months ago)
- Last Synced: 2024-11-08T18:31:15.414Z (2 months ago)
- Language: C
- Size: 11.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# get_next_line 📜
This project is all about creating a function that reads a line from a file descriptor in C. **get_next_line** efficiently handles reading files of any size, line by line, without using any pre-built functions that automatically handle line breaks.
## Project Description
The **get_next_line** project, part of the [42 School](https://42.fr/) curriculum, focuses on building a custom function that reads from a file descriptor and returns one line at a time. This function replicates the behavior of a standard line-reading function, but with strict constraints that make it more challenging to handle memory and buffering efficiently.
## Objective
The purpose of **get_next_line** is to:
- Develop a function that reads from any file descriptor, including files and standard input.
- Return each line of the file (or input) until the end is reached.
- Manage a buffer to handle large files or inputs efficiently without memory leaks.
The project strengthens skills in dynamic memory management, string manipulation, and working with buffers.
## Function Prototype
The prototype for **get_next_line** is as follows:
```c
char *get_next_line(int fd);
```
- **fd**: The file descriptor to read from.
- **Return Value**: Returns the next line from the file descriptor, or `NULL` when there are no more lines to read.
## Key Features
- **Buffer Management**: Uses a buffer to store read characters, handling both short and long lines seamlessly.
- **Dynamic Memory Allocation**: Manages memory dynamically for each line, ensuring no leaks occur during usage.
- **Reusable Across Descriptors**: The function can handle multiple descriptors, making it versatile for various input sources.
## Installation
To add **get_next_line** to your project:
1. **Clone the repository**:
```bash
git clone https://github.com/asut00/get_next_line.git
cd get_next_line
```
2. **Compile the function**:
Add the source files `get_next_line.c` and `get_next_line_utils.c` to your project and compile as follows:
```bash
gcc -Wall -Wextra -Werror -D BUFFER_SIZE=42 main.c get_next_line.c get_next_line_utils.c -o gnl_test
```
Replace `BUFFER_SIZE` with the buffer size you prefer (e.g., 42, 1024).
## Usage
Here’s how to use **get_next_line** in a sample program:
```c
#include
#include "get_next_line.h"
int main() {
int fd = open("example.txt", O_RDONLY);
char *line;
if (fd == -1)
return (1);
while ((line = get_next_line(fd)) != NULL) {
printf("%s", line);
free(line);
}
close(fd);
return (0);
}
```
In this example, **get_next_line** reads each line from `example.txt` and prints it to the standard output.
## Buffer Size
The `BUFFER_SIZE` is an important variable that determines how many bytes **get_next_line** reads at a time. Adjusting this value can affect the function’s performance:
- **Small Buffer**: Less memory usage but potentially slower.
- **Large Buffer**: Faster for large files, though it may consume more memory.
Experiment with different values to find the optimal balance for your use case.
## Limitations and Edge Cases
While **get_next_line** is a powerful tool, there are a few considerations:
- **End of File (EOF)**: The function returns `NULL` when all lines have been read or if an error occurs.
- **Empty Lines**: It correctly handles empty lines within the file.
- **Memory Leaks**: Ensure each returned line is freed after use to prevent memory leaks.
## Author
- GitHub: [@asut00](https://github.com/asut00)
- 42 Intra: `asuteau`