Functions for handling and manipulating C strings. More...

Files
file	ft_split.c
	Splits a string into substrings using a single delimiter character.

file	ft_split_charset.c
	Splits a string into substrings based on a set of delimiters.

file	ft_string.c
	Returns the number of characters in a string.

file	ft_string.h
	String manipulation utility functions.

file	ft_strtrim.c
	Trims characters from the beginning and end of a string.

file	skip_whitespace.c
	Utility functions to skip leading whitespace in C strings.

Functions
char *	ft_itoa (int n)
	Converts an integer to a string.

char **	ft_split (const char *s, char c)
	Splits a string into substrings based on a delimiter character.

char **	ft_split_charset (char s, char charset)
	Splits a string into substrings based on a character set.

char *	ft_strcat (char dest, const char src)
	Appends the `src` string to the end of the `dest` string.

char *	ft_strchr (const char *str, int c)
	Finds the first occurrence of a character in a string.

int	ft_strcmp (const char s1, const char s2)
	Compares two strings lexicographically.

char *	ft_strcpy (char dst, const char src)
	Compares two strings lexicographically.

char *	ft_strdup (const char *src)
	Allocates and duplicates a null-terminated string.

void	ft_striteri (char s, void(f)(unsigned int, char *))
	Applies a function to each character of a string, passing its index.

char *	ft_strjoin (const char s1, const char s2)
	Concatenates two strings into a newly allocated string.

char *	ft_strjoin_and_free (char s1, char s2, int free_s1, int free_s2)

size_t	ft_strlcat (char dest, const char src, size_t size)
	Concatenates `src` to the end of `dest` while ensuring null-termination.

size_t	ft_strlcpy (char dest, const char src, size_t size)
	Copies a string from `src` to `dest`, up to `size` - 1 characters.

size_t	ft_strlen (const char *str)

char *	ft_strmapi (char const s, char(f)(unsigned int, char))
	Applies a function to each character of a string to create a new string.

int	ft_strncmp (const char s1, const char s2, size_t n)
	Compares two strings up to `n` characters.

char *	ft_strndup (const char *src, size_t n)
	Creates a copy of a string, up to `n` characters.

char *	ft_strnstr (const char big, const char little, size_t len)
	Searches for a substring in a string within a max length.

char *	ft_strrchr (const char *str, int c)
	Returns a pointer to the last occurrence of a character in a string.

char *	ft_strtrim (const char s1, const char set)
	Trims characters from both ends of a string.

char *	ft_substr (const char *s, unsigned int start, size_t len)
	Extracts a substring from a string.

int	ft_tolower (int c)
	Converts a character to lowercase.

int	ft_toupper (int c)
	Converts a character to uppercase.

void	skip_whitespace_index (const char input, int i)
	Skips leading whitespace by incrementing a pointer index.

char *	skip_whitespace_ptr (const char *s)
	Returns a pointer to the first non-whitespace character.

Detailed Description

Functions for handling and manipulating C strings.

This group includes common string operations such as copying, concatenation, trimming, splitting, searching, and case conversion.

Useful for tasks like:

Extracting substrings
Skipping whitespace
Finding characters or substrings
Transforming string content

Function Documentation

◆ ft_itoa()

char * ft_itoa ( int n )

#include <srcs/convert/ft_number_conversion.c>

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_split()

char ** ft_split	(	const char *	s,
		char	c
	)

#include <include/ft_string.h>

Splits a string into substrings based on a delimiter character.

Splits the input string s into substrings separated by the delimiter c. The resulting substrings are stored in a newly allocated NULL-terminated array.

Parameters

s	The string to split.
c	The delimiter character.

Returns: A newly allocated array of substrings, or NULL on failure.

Note: The input string is not modified. Each substring and the array itself must be freed manually using ft_free_array.

See also: ft_w_count; ft_fill_array; ft_substr; ft_free_array

◆ ft_split_charset()

char ** ft_split_charset	(	char *	s,
		char *	charset
	)

#include <include/ft_string.h>

Splits a string into substrings based on a character set.

This function splits the input string s into substrings using the set of delimiter characters defined in charset. Each substring is allocated dynamically and stored in a NULL-terminated array.

Parameters

s	The string to split.
charset	The set of delimiter characters.

Returns: A newly allocated array of substrings, or NULL on error.

See also: ft_w_count_charset; ft_fill_array_charset; ft_free_array

◆ ft_strcat()

char * ft_strcat	(	char *	dest,
		const char *	src
	)

#include <include/ft_string.h>

Appends the src string to the end of the dest string.

This function assumes that dest points to a buffer large enough to hold the resulting string, including the null terminator.

Parameters

dest	The destination string to which `src` will be appended.
src	The source string to append.

Returns: A pointer to the destination string (dest).

Note: The behavior is undefined if the destination buffer is not large enough to contain the result.

◆ ft_strchr()

char * ft_strchr	(	const char *	str,
		int	c
	)

#include <include/ft_string.h>

Finds the first occurrence of a character in a string.

Searches for the first occurrence of the character c in the string str. The terminating null byte (\0) is considered part of the string.

Parameters

str	The null-terminated string to search in.
c	The character to search for, interpreted as an unsigned char.

Returns: A pointer to the first occurrence of c in str, or NULL if c is not found.

◆ ft_strcmp()

int ft_strcmp	(	const char *	s1,
		const char *	s2
	)

#include <include/ft_string.h>

Compares two strings lexicographically.

This function compares the characters of s1 and s2 one by one. The comparison stops at the first differing character or when a null byte is reached.

Parameters

s1	Pointer to the first null-terminated string.
s2	Pointer to the second null-terminated string.

Returns: An integer less than, equal to, or greater than 0 if s1 is found to be less than, equal to, or greater than s2, respectively.

Note: The comparison is done using unsigned char values.

See also: ft_strncmp; ft_strcmp

◆ ft_strcpy()

char * ft_strcpy	(	char *	dst,
		const char *	src
	)

#include <include/ft_string.h>

Compares two strings lexicographically.

This function compares the characters of s1 and s2 one by one. The comparison stops at the first differing character or when a null byte is reached.

Parameters

s1	Pointer to the first null-terminated string.
s2	Pointer to the second null-terminated string.

Returns: An integer less than, equal to, or greater than 0 if s1 is found to be less than, equal to, or greater than s2, respectively.

◆ ft_strdup()

char * ft_strdup ( const char * src )

#include <include/ft_string.h>

Allocates and duplicates a null-terminated string.

Allocates memory for a copy of the string src, copies its contents (including the null terminator), and returns a pointer to the new string.

Parameters

src	The source string to duplicate.

Returns: A pointer to the newly allocated string, or NULL on allocation failure.

See also: ft_strlcpy; ft_strlen

◆ ft_striteri()

void ft_striteri	(	char *	s,
		void()(unsigned int, char )	f
	)

#include <include/ft_string.h>

Applies a function to each character of a string, passing its index.

Iterates over the string s and applies the function f to each character. The function receives the index of the character and a pointer to it, allowing in-place modification.

Parameters

s	The string to iterate over.
f	The function to apply to each character.

Note: If either s or f is NULL, the function does nothing.

◆ ft_strjoin()

char * ft_strjoin	(	const char *	s1,
		const char *	s2
	)

#include <include/ft_string.h>

Concatenates two strings into a newly allocated string.

Allocates a new string containing the contents of s1 followed by s2. If either string is NULL, it is treated as an empty string.

Parameters

s1	The first string.
s2	The second string.

Returns: A new string containing the concatenation of s1 and s2, or NULL if memory allocation fails.

Note: The caller is responsible for freeing the returned string.

See also: ft_strlen; ft_strlcpy

◆ ft_strjoin_and_free()

char * ft_strjoin_and_free	(	char *	s1,
		char *	s2,
		int	free_s1,
		int	free_s2
	)

#include <include/ft_string.h>

◆ ft_strlcat()

size_t ft_strlcat	(	char *	dest,
		const char *	src,
		size_t	size
	)

#include <include/ft_string.h>

Concatenates src to the end of dest while ensuring null-termination.

This function appends the src string to the end of the dest string. It ensures that the result fits within the buffer size given by size, including the null-terminator. If size is less than or equal to the length of dest, the function returns size + strlen(src) without appending.

Parameters

dest	The destination buffer.
src	The source string to append.
size	The total size of the destination buffer.

Returns: The total length of the string it tried to create: strlen(dest) + strlen(src). This value can be used to detect truncation.

See also: ft_strlen; ft_strlcpy

◆ ft_strlcpy()

size_t ft_strlcpy	(	char *	dest,
		const char *	src,
		size_t	size
	)

#include <include/ft_string.h>

Copies a string from src to dest, up to size - 1 characters.

Copies up to size - 1 characters from the null-terminated string src to dest, null-terminating the result. If size is 0, nothing is written to dest, but the length of src is still returned.

Parameters

dest	Destination buffer.
src	Source null-terminated string to copy.
size	Total size of destination buffer.

Returns: The length of src. This allows detection of truncation: if the return value is >= size, truncation occurred.

◆ ft_strlen()

size_t ft_strlen ( const char * str )

#include <include/ft_string.h>

◆ ft_strmapi()

char * ft_strmapi	(	char const *	s,
		char(*)(unsigned int, char)	f
	)

#include <include/ft_string.h>

Applies a function to each character of a string to create a new string.

Allocates a new string where each character is the result of applying the given function f to the corresponding character of the input string s. The function f receives the index of each character as its first argument.

Parameters

s	The original null-terminated string to map.
f	The function to apply to each character, receiving the index and the character.

Returns: A new string with transformed characters, or NULL if allocation fails or if input is NULL.

Note: The returned string must be freed by the caller.

◆ ft_strncmp()

int ft_strncmp	(	const char *	s1,
		const char *	s2,
		size_t	n
	)

#include <include/ft_string.h>

Compares two strings up to n characters.

This function compares the first n characters of the strings s1 and s2. The comparison is done using unsigned characters.

Parameters

s1	First string to compare.
s2	Second string to compare.
n	Maximum number of characters to compare.

Returns: An integer less than, equal to, or greater than 0 if s1 is found, respectively, to be less than, to match, or be greater than s2.

Note: The comparison stops when a difference is found, a null byte is encountered, or n characters have been compared.

◆ ft_strndup()

char * ft_strndup	(	const char *	src,
		size_t	n
	)

#include <include/ft_string.h>

Creates a copy of a string, up to n characters.

This function allocates memory and copies at most n characters from the string src to a new string. The new string is always null-terminated.

Parameters

src	The source string to duplicate.
n	The maximum number of characters to copy.

Returns: A pointer to the newly allocated string, or NULL if memory allocation fails.

See also: ft_strlcpy; ft_strlen

◆ ft_strnstr()

char * ft_strnstr	(	const char *	big,
		const char *	little,
		size_t	len
	)

#include <include/ft_string.h>

Searches for a substring in a string within a max length.

This function searches for the first occurrence of the null-terminated string little in the string big, where not more than len characters are searched. Characters after a \0 character are not searched.

If little is an empty string, big is returned. If little occurs nowhere in big within the first len characters, NULL is returned.

Parameters

big	The main string to be searched.
little	The substring to search for.
len	The maximum number of characters to search in `big`.

Returns: A pointer to the first occurrence of little in big within len characters, or NULL if not found.

◆ ft_strrchr()

char * ft_strrchr	(	const char *	str,
		int	c
	)

#include <include/ft_string.h>

Returns a pointer to the last occurrence of a character in a string.

Scans the string str for the last occurrence of the character c (interpreted as an unsigned char). If found, a pointer to the character is returned. If not, NULL is returned.

If c is '\0', a pointer to the null terminator at the end of the string is returned.

Parameters

str	The null-terminated string to be searched.
c	The character to search for (casted to `unsigned char`).

Returns: A pointer to the last occurrence of c in str, or NULL if not found.

◆ ft_strtrim()

char * ft_strtrim	(	const char *	s1,
		const char *	set
	)

#include <include/ft_string.h>

Trims characters from both ends of a string.

Allocates and returns a new string derived from s1 with all characters found in set removed from both the beginning and the end. The returned string is NULL-terminated and dynamically allocated.

Parameters

s1	The original null-terminated string to trim.
set	The set of characters to remove.

Returns: A newly allocated trimmed string, or NULL on allocation failure.

Note: If the trimmed result is empty, the function returns a string containing only '\0'. The caller is responsible for freeing the result.

See also: ft_trim_start; ft_trim_end; ft_strlcpy

◆ ft_substr()

char * ft_substr	(	const char *	s,
		unsigned int	start,
		size_t	len
	)

#include <include/ft_string.h>

Extracts a substring from a string.

Allocates and returns a new string, which is a substring of s starting from index start and up to len characters long. If start is greater than or equal to the length of s, an empty string is returned. The length of the returned substring is either len or the remaining length from start, whichever is smaller.

Parameters

s	The source string.
start	The starting index in the source string.
len	The maximum number of characters to copy.

Returns: A newly allocated string containing the substring, or NULL if memory allocation fails. If start is out of bounds, an empty string is returned.

See also: ft_strlen; ft_strlcpy

◆ ft_tolower()

int ft_tolower ( int c )

#include <include/ft_string.h>

Converts a character to lowercase.

If the character c is an uppercase letter (between 'A' and 'Z'), it is converted to its lowercase equivalent by adding the difference between the ASCII values of 'a' and 'A'. If c is not an uppercase letter, the function returns c unchanged.

Parameters

c	The character to convert.

Returns: The lowercase version of c if it is an uppercase letter; otherwise, returns c unchanged.

See also: ft_toupper

◆ ft_toupper()

int ft_toupper ( int c )

#include <include/ft_string.h>

Converts a character to uppercase.

If the character c is a lowercase letter (between 'a' and 'z'), it is converted to its uppercase equivalent by subtracting the difference between the ASCII values of 'a' and 'A'. If c is not a lowercase letter, the function returns c unchanged.

Parameters

c	The character to convert.

Returns: The uppercase version of c if it is a lowercase letter; otherwise, returns c unchanged.

See also: ft_tolower

◆ skip_whitespace_index()

void skip_whitespace_index	(	const char *	input,
		int *	i
	)

#include <include/ft_string.h>

Skips leading whitespace by incrementing a pointer index.

This function iterates through the input string from the position indicated by the index *i, incrementing the index until a non-whitespace character is reached. Whitespace is detected using ft_isspace.

Parameters

input	The string to search for whitespace.
i	Pointer to the current index, which will be updated in-place.

See also: skip_whitespace_ptr

◆ skip_whitespace_ptr()

char * skip_whitespace_ptr ( const char * s )

#include <include/ft_string.h>

Returns a pointer to the first non-whitespace character.

Iterates through the string s and returns a pointer to the first character that is not a whitespace character. If all characters are whitespace, returns a pointer to the null-terminator.

Parameters

s	The string to scan.

Returns: A pointer to the first non-whitespace character, or to '\0'.

See also: skip_whitespace_index

Files

Functions

Detailed Description

Function Documentation

◆ ft_itoa()

◆ ft_split()

◆ ft_split_charset()

◆ ft_strcat()

◆ ft_strchr()

◆ ft_strcmp()

◆ ft_strcpy()

◆ ft_strdup()

◆ ft_striteri()

◆ ft_strjoin()

◆ ft_strjoin_and_free()

◆ ft_strlcat()

◆ ft_strlcpy()

◆ ft_strlen()

◆ ft_strmapi()

◆ ft_strncmp()

◆ ft_strndup()

◆ ft_strnstr()

◆ ft_strrchr()

◆ ft_strtrim()

◆ ft_substr()

◆ ft_tolower()

◆ ft_toupper()

◆ skip_whitespace_index()

◆ skip_whitespace_ptr()