File Utilities

Helper functions for basic file operations. More...

Files
file	ft_file.h
	File utility functions for simplified and safe file operations.
file	get_next_line.c
	Implementation of the get_next_line function.

Macros
#define	BUFFER_SIZE   1024
	Default buffer size for reading operations like get_next_line.
#define	MAX_FD   1024
	Maximum number of file descriptors supported simultaneously.

Functions
static char *	extract_line (char *remainder)
	Extracts the next line from the remainder buffer.
int	ft_open_file (const char *filename, int flags)
	Opens a file with the given flags.
ssize_t	ft_read_file (int fd, void *buffer, size_t size)
	Reads a specified number of bytes from a file descriptor.
int	ft_safe_close (int fd)
	Closes a file descriptor safely.
char *	get_next_line (int fd)
	Reads a line from a file descriptor.
static ssize_t	read_and_store (int fd, char **remainder)
	Reads from a file descriptor and appends to the remainder buffer.
static char *	update_remainder (char *remainder)
	Updates the remainder buffer after a line has been extracted.

Detailed Description

Helper functions for basic file operations.

These functions simplify and secure standard file operations, including reading, opening, closing, and line-by-line parsing.

This group includes:

• ft_open_file
• ft_read_file
• ft_safe_close
• get_next_line

Macro Definition Documentation

BUFFER_SIZE

#define BUFFER_SIZE   1024

#include <include/ft_file.h>

Default buffer size for reading operations like get_next_line.

MAX_FD

#define MAX_FD   1024

#include <include/ft_file.h>

Maximum number of file descriptors supported simultaneously.

Used internally to manage static buffers indexed by file descriptors.

Function Documentation

extract_line()

static char * extract_line ( char *  remainder )

static

#include <srcs/file_utils/get_next_line.c>

Extracts the next line from the remainder buffer.

Allocates and returns a new string containing everything from the start of remainder up to and including the first newline, or up to the null terminator if no newline is found.

Parameters

remainder

The remainder buffer.

Returns

New allocated line string, or NULL if empty.

See also

ft_substr

ft_open_file()

int ft_open_file	(	const char *	filename,
		int	flags
	)

#include <include/ft_file.h>

Opens a file with the given flags.

Safely opens a file with the given flags.

Parameters

filename	The path to the file.
flags	Flags such as O_RDONLY, O_WRONLY, etc.

Returns

The file descriptor on success, or -1 on failure.

If the provided filename is NULL or if open fails, this function reports the error to stderr using perror.

Parameters

filename	The path to the file to be opened.
flags	File access flags (e.g., O_RDONLY, O_WRONLY).

Returns

The file descriptor on success, or -1 on failure.

Note

This function is useful for reducing boilerplate when opening files.

ft_read_file()

ssize_t ft_read_file	(	int	fd,
		void *	buffer,
		size_t	size
	)

#include <include/ft_file.h>

Reads a specified number of bytes from a file descriptor.

Safely reads data from a file descriptor.

Parameters

fd	The file descriptor to read from.
buffer	The buffer to store the read data.
size	The number of bytes to read.

Returns

The number of bytes read, or -1 on error.

This function validates the file descriptor and buffer before attempting to read. On failure, it prints a message to stderr.

Parameters

fd	The file descriptor to read from.
buffer	Pointer to the destination buffer.
size	Number of bytes to read.

Returns

The number of bytes read on success, or -1 on error.

Note

This function helps avoid common misuse of read().

ft_safe_close()

int ft_safe_close

(

int

fd

)

#include <include/ft_file.h>

Closes a file descriptor safely.

Safely closes a file descriptor.

Parameters

fd	The file descriptor to close.

Returns

0 on success, or -1 on error.

This function closes a valid file descriptor and reports any error using perror.

Parameters

fd	The file descriptor to close.

Returns

0 on success, or -1 if closing fails.

Note

This function should always be used to close file descriptors in a safe and consistent manner.

get_next_line()

char * get_next_line

(

int

fd

)

#include <include/ft_file.h>

Reads a line from a file descriptor.

Reads the next line from a file descriptor.

This function returns a line terminated by a newline character \n, or the end of file.

Parameters

fd	The file descriptor to read from.

Returns

A newly allocated string containing the line, or NULL on failure.

This function returns the next line read from fd. It uses static storage to preserve context across calls and handles files independently.

Parameters

fd	The file descriptor to read from.

Returns

The next line, or NULL if EOF or an error occurs.

Note

Caller is responsible for freeing the returned string.

Depends on BUFFER_SIZE and MAX_FD being defined.

See also

read_and_store

extract_line

update_remainder

read_and_store()

static ssize_t read_and_store ( int  fd, char **  remainder  )

static

#include <srcs/file_utils/get_next_line.c>

Reads from a file descriptor and appends to the remainder buffer.

Allocates a temporary buffer and appends read data to the remainder until a newline is found or EOF is reached. It handles reallocation and joins partial strings dynamically.

Parameters

fd	The file descriptor to read from.
remainder	Pointer to the pointer holding current remainder.

Returns

Number of bytes read on success, -1 on error.

See also

ft_strdup

ft_strchr

ft_strjoin

update_remainder()

static char * update_remainder ( char *  remainder )

static

#include <srcs/file_utils/get_next_line.c>

Updates the remainder buffer after a line has been extracted.

Frees the old remainder and returns a newly allocated string containing the part of the original string after the first newline.

Parameters

remainder

The buffer to update.

Returns

A new remainder string, or NULL if nothing is left.

See also

ft_strlen

ft_substr