Number Conversion Utilities

String ↔ number conversion and formatting. More...

Files
file	ft_convert.h
	Numeric conversion utility functions.
file	ft_number_conversion.c
	Number-to-string and string-to-number conversion functions.

Functions
long long	ft_atoi (const char *str)
	Converts a string to a signed integer.
long long	ft_atoll (const char *str)
	Converts a string to a long long value.
static size_t	ft_baselen (unsigned long long n, int base)
	Calculates the number of digits to represent a value in a given base.
static bool	ft_check_overflow (long long num, char digit, int sign)
	Checks for overflow when converting a string to a long long integer.
char *	ft_itoa (int n)
	Converts an integer to a string.
char *	ft_itoa_base (unsigned long long n, int base, int uppercase)
	Converts an unsigned integer to a string in a given base.
char *	ft_utoa (unsigned long long n)
	Converts an unsigned long long to a decimal string.

Detailed Description

String ↔ number conversion and formatting.

This group provides functions to convert strings to numbers (like ft_atoi and ft_atoll) with overflow detection, and to format unsigned integers into strings, optionally in base 2 to 16.

This group includes:

• ft_atoi
• ft_atoll
• ft_utoa
• ft_itoa_base

Function Documentation

ft_atoi()

long long ft_atoi

(

const char *

str

)

#include <include/ft_convert.h>

Converts a string to a signed integer.

Converts the null-terminated string str to a long long value. Handles optional leading whitespace, sign, and overflow.

Parameters

str	The string to convert.

Returns

The converted value or ATOI_ERROR on overflow.

See also

ft_check_overflow

ATOI_ERROR

ft_atoll()

long long ft_atoll

(

const char *

str

)

#include <include/ft_convert.h>

Converts a string to a long long value.

Similar to ft_atoi, but does not cast to int and returns a full long long result. Handles whitespace, signs, and overflow.

Parameters

str	The string to convert.

Returns

The converted value or ATOI_ERROR on overflow.

See also

ft_check_overflow

ATOI_ERROR

ft_baselen()

static size_t ft_baselen ( unsigned long long  n, int  base  )

static

#include <srcs/convert/ft_number_conversion.c>

Calculates the number of digits to represent a value in a given base.

Computes how many characters are needed to express n in base base. Used internally by ft_itoa_base.

Parameters

n	The number to analyze.
base	The numerical base (2–16).

Returns

The number of digits required to represent n.

ft_check_overflow()

static bool ft_check_overflow ( long long  num, char  digit, int  sign  )

static

#include <srcs/convert/ft_number_conversion.c>

Checks for overflow when converting a string to a long long integer.

Evaluates whether appending a digit to num would cause it to overflow a signed 32-bit integer, taking into account the current sign.

Parameters

num	The current number being built.
digit	The current character digit to append.
sign	The number sign (1 for positive, -1 for negative).

Returns

true if overflow would occur, false otherwise.

See also

ft_atoi

ft_itoa()

char * ft_itoa

(

int

n

)

#include <include/ft_convert.h>

Converts an integer to a string.

Allocates and returns a new string representing the integer n. Handles negative numbers and returns NULL if allocation fails.

Parameters

n	The integer to convert.

Returns

A null-terminated string representing n, or NULL on failure.

ft_itoa_base()

char * ft_itoa_base	(	unsigned long long	n,
		int	base,
		int	uppercase
	)

#include <include/ft_convert.h>

Converts an unsigned integer to a string in a given base.

Converts the unsigned number n to a string in base base (2–16). Uses lowercase or uppercase digits based on uppercase.

Parameters

n	The number to convert.
base	The base for conversion (2–16).
uppercase	If 1, use uppercase letters for bases > 10.

Returns

A newly allocated null-terminated string, or NULL on failure.

See also

ft_baselen

ft_utoa()

char * ft_utoa

(

unsigned long long

n

)

#include <include/ft_convert.h>

Converts an unsigned long long to a decimal string.

Converts the value n to its decimal string representation. A null-terminated string is returned. The caller must free it.

Parameters

n	The number to convert.

Returns

A dynamically allocated string, or NULL on allocation failure.