TakuyaSama/libft_42

42's libft with descriptions to understand what each function does and how it works.

Libft - @42Born2Code

TOC

• What is libft?
• What's in it?
• List of functions Click to each function to see an explication

What is libft?

Libft is an individual project at 42 that requieres us to re-create some standard C library functions for future projects, and have a deeper understanding of data structures and basic algorithms. At 42 we are not allowed to use some standard libraries on our projects, so we have to keep growing this libary with our own functions as we go farther in the program.

What's in it?

There are 4 sections:

1. Libc Functions: Some of the standard C functions
2. Additional functions: Functions that will be useful for later projects
3. Bonus Functions: Functions that will be useful for linked list manipulation
4. Personal Functions: Functions I believe will be useful later.

List of functions

Libc functions	Additional functions	Bonus Functions	Personal Functions
ft_memset	ft_substr	ft_lstnew	ft_islower
ft_bzero	ft_strjoin	ft_lstadd_front	ft_isupper
ft_memcpy	ft_strtrim	ft_lstsize	ft_isspace
ft_memccpy	ft_split	ft_lstlast	ft_strndup
ft_memmove	ft_itoa	ft_lstadd_back	ft_strcdup
ft_memchr	ft_strmapi	ft_lstdelone]
ft_memcmp	ft_putchar_fd	ft_lstclear
ft_strlen	ft_putstr_fd	ft_lstiter
ft_strdup	ft_putendl_fd	ft_lstmap
ft_strcpy	ft_putnbr_fd
ft_strlcpy
ft_strcat
ft_strlcat
ft_strchr
ft_strrchr
ft_strstr
ft_strnstr
ft_strcmp
ft_strncmp
ft_atoi
ft_isalpha
ft_isdigit
ft_isalnum
ft_isascii
ft_isprint
ft_toupper
ft_tolower
ft_calloc

ft_memset

void *ft_memset(void *s, int c, size_t len)

Description	Param. #1	Param. #2	Param. #3	Return Value
Fill with "len" bytes of "c" the memory of "s"	The string on which to operate	Value c (converted to an unsigned char)	The number of bytes	A pointer to the memory area s

ft_bzero

void *ft_bzero(void *s, size_t n)

Description	Param. #1	Param. #2	Return Value
Erases the data in the "n" bytes of the memory starting at the location pointed by "s" writing zeroes	The string on which to operate	The number of bytes	None

ft_memcpy

void *ft_memcpy(void *dst, const void *src, size_t n)

Description	Param. #1	Param. #2	Param. #3	Return Value
Copies n bytes from memory area src to memory of dst. The memory areas must not overlap. Use ft_memmove if the memory areas do overlap.	Memory area dst	Memory area src	The number of bytes	A pointer to the memory area dst

ft_memccpy

void *ft_memccpy(void *dst, const void *src, int c, size_t n)

Description	Param. #1	Param. #2	Param. #3	Param. #4	Return Value
Copies n bytes from memory area src to memory area dst, stopping when the character c is found, or after n characters are copied, whichever comes first. If copying takes place between objects that overlap, the behavior is undefined.	Memory area dst	Memory area src	A character to search	Number of bytes that memccpy() copied	A pointer to the next character in dst after c, or NULL if c was not found in the first n bytes

ft_memmove

void *ft_memmove(void *dst, const void *src, size_t len)

Description	Param. #1	Param. #2	Param. #3	Return Value
Copies len bytes from the memory of src to dst. Memories may overlap. First, the bytes in src are copied into a temporary array and then to dst.	Memory area dst	Memory ares arc	The number of bytes	A pointer to the memory area dst

ft_memchr

void *ft_memchr(const void *s, int c, size_t n)

Description	Param. #1	Param. #2	Param. #3	Return Value
Scans the initial n bytes of s for the first instance of c	Memory area s	A character to search	The number of bytes	A pointer to the matching byte or NULL if the character does not occur in the given memory area

ft_memcmp

void *ft_memcmp(void *dst, const void *src, size_t n)

Description	Param. #1	Param. #2	Param. #3	Return Value
Compares byte string s1 against byte string s2	Memory area s1	Memory area s2	The number of bytes	< 0 if s1 is less than s2, > 0 if s1 is graeter than s2, = 0 if s1 is equal to s2

ft_strlen

size_t ft_strlen(const char *s)

Description	Param. #1	Return Values
Calculates the length of the string pointed to by s, excluding the terminating null byte ('\0')	The string to calculate	Number of characters in the string pointed to by s

ft_strdup

char *ft_strdup(const char *s))

Description	Param. #1	Return Values
Duplicate string s1. Memory for the new string is obtained with malloc, and can be freed with free	The string to duplicate	A pointer to the duplicated string. NULL if insufficient memory was available

ft_strndup

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

Description	Param. #1	Param. #2	Return Value
Allocates a specific amount of memory to copy a string	The string to copy	The maximum amount of characters to copy from the string	A pointer to the new string

ft_strcdup

char *ft_strcdup(const char *s, int c)

Description	Param. #1	Param. #2	Return Value
Allocates a specific amount of memory to copy a string until the occurence of c. Example: ft_strcdup("Blue", 'u') -> "Bl"	The string to copy before c	The character c	A pointer to the new string

ft_strchr

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

Description	Param. #1	Param. #2	Return Value
Locates the first occurrence of 'c' in the string pointed to by 's'. The terminating null character is considered to be part of the string, therefore if 'c' is '\0', locates the terminating '\0'	Pointer to string	Character to be located	A pointer to the first occurrence of the character c in the string or NULL if the character is not found

ft_strrchr

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

Description	Param. #1	Param. #2	Return Value
Locates the last occurrence of 'c' in the string pointed to by 's'. The terminating null character is considered to be part of the string, therefore if 'c' is '\0', locates the terminating '\0'	Pointer to string	Character to be located	A pointer to the last occurrence of the character c in the string or NULL if the character is not found

ft_strcpy

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

Description	Param. #1	Param. #2	Return Value
Copy a string, including the terminating null byte ('\0')	Destination array	String to be copied	A pointer to the destination string dst

ft_strlcpy

size_t ft_strlcpy(char *dst, const char *src, size_t dstsize)

Description	Param. #1	Param. #2	Param. #3	Return Value
Copies up to dstsize - 1 characters from the NUL-terminated string src to dst, NUL-terminating the result	Destination array	String to be copied	Number of characters to be copied from src	Total length of the string to create (length of src)

ft_strcat

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

Description	Param. #1	Param. #2	Return Value
Concatenate two strings (append s2 to s1), including the terminating null byte ('\0')	Destination array	String to be appended to dst	A pointer to the resulting string dst

ft_strlcat

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

Description	Param. #1	Param. #2	Param. #3	Return Value
Concatenate the string src to the end of dst. It will concatenate at most size - strlen(dst) - 1 bytes, NUL-terminating the result	Destination array	String to be appended to dst	Maximum number of characters to be appended	The initial length of dst plus the length of src

ft_strstr

char *ft_strstr(const char *haystack, const char *needle)

Description	Param. #1	Param. #2	Return Value
Locate substring. Finds the first occurrence of the substring 'needle' in the string 'haystack'. The terminating null bytes ('\0') are not compared	String to be scanned	The small string to be searched in haystack string	A pointer to the beginning of the located substring. NULL if the substring is not found. If 'needle' is an empty string, 'haystack' is returned

ft_strnstr

char *ft_strnstr(const char *haystack, const char *needle, size_t len)

Description	Param. #1	Param. #2	Param. #3	Return Value
Locate substring, where not more than 'len' characters are searched. Finds the first occurrence of the substring 'needle' in the string 'haystack'. The terminating null bytes ('\0') are not compared.	String to be scanned	The small string to be searched in 'haystack' string	The maximum amount of characters to be searched	A pointer to the first character of the first occurrence of little is returned. NULL if the substring is not found. If 'needle' is an empty string, 'haystack' is returned

ft_atoi

int ft_atoi(const char *str)

Description	Param. #1	Return Value
Convert a string to a integer	The string to be converted to int	The converted value

ft_isalpha

int ft_isalpha(int c)

Description	Param. #1	Return Value
Check for a alpabetic character, it is equivalent to (ft_isupper(c) or ft_islower(c))	The character to test	0 if the character tests false and 1 if the character tests true

ft_isdigit

int ft_isdigit(int c)

Description	Param. #1	Return Value
Check for a digit (0 through 9)	The character to test	0 if the character tests false and 1 if the character tests true

ft_isalnum

int ft_isalnum(int c)

Description	Param. #1	Return Value
Check for an alphanumeric character; it is equivalent to (ft_isalpha or ft_isdigit)	The character to test	0 if the character tests false and 1 if the character tests true

ft_isascii

int ft_isascii(int c)

Description	Param. #1	Return Value
Checks for an ASCII character, which is any character between 0 and octal 0177 inclusive	The character to test	0 if the character tests false and 1 if the character tests true

ft_isprint

int ft_isprint(int c)

Description	Param. #1	Return Value
Checks for any printable character including space	The character to test	0 if the character tests false and 1 if the character tests true

ft_toupper

int ft_toupper(int c)

Description	Param. #1	Return Value
If the character passed as an argument is a lowercase, convert to upper	The character to convert	If c is a lowercase letter, returns its uppercase equivalent. Otherwise, it returns c.

ft_tolower

int ft_tolower(int c)

Description	Param. #1	Return Value
If the character passed as an argument is an uppercase, convert to lower	The character to convert	If c is a uppercase letter, returns its lowercase equivalent. Otherwise, it returns c.

ft_calloc

void *ft_calloc(size_t count, size_t size)

Description	Param. #1	Param. #2	Return Value
Allocates enough space for count objects that are size bytes of memory each, and returns a pointer to the allocated memory. The allocated memory is filled with bytes of value zero	Number of elements to be allocated	Size of elements	A pointer to the allocated memory, or NULL if the request fails

[ft_substr]

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

Description	Param. #1	Param. #2	Param. #3	Return Value
Allocates (with malloc) and returns a substring from the string given in argument. The substring begins at index 'start' and is of maximum size 'len'	The string from which create the substring	The start index of the substring in the string	The maximum length of the substring	The substring. NULL if the allocation fails

[ft_strjoin]

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

Description	Param. #1	Param. #2	Return Value
Allocates (with malloc) and returns a new string, result of the concatenation of s1 and s2	The prefix string	The suffix string	The new string. NULL if the allocation fails

[ft_strtrim]

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

Description	Param. #1	Param. #2	Return Value
Allocates (with malloc) and returns a copy of the string given as argument without the characters specified in the set argument at the beginning and the end of the string	The string to be trimmed	The reference set of character to trim	The trimmed string. NULL if the allocation fails

[ft_strsplit]

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

Description	Param. #1	Param. #2	Return Value
Allocates (with malloc) and returns an array of strings obtained by splitting s using the character 'c' as a delimiter. The array must be ended by a NULL pointer	The string to be split	The delimiter character	The array of new strings result of the split. NULL if the allocation fails

[ft_strmapi]

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

Description	Param. #1	Param. #2	Return Value
Applies the function f to each character of the string passed as argument to create a new string (with malloc) resulting from successive applications of f	The string on which to iterate	The function to apply to each character	The string created from the successive applications of f. Returns NULL if the allocation fails

[ft_atoi]

char ft_itoa(int n)

Description	Param. #1	Return Value
Allocates (with malloc) and returns a string representing the integer received as an argument. Negative numbers must be handled	The integer to convert	The string representing the integer. NULL if the allocation fails.

ft_islower

int ft_islower(int c)

Description	Param. #1	Return Value
Check for a lowercase character	The character to test	0 if the character tests false and 1 if the character tests true

ft_isupper

int ft_isupper(int c)

Description	Param. #1	Return Value
Check for an uppercase character	The character to test	0 if the character tests false and 1 if the character tests true

ft_isspace

int ft_isspace(int c)

Description	Param. #1	Return Value
Checks for white-space characters. These are: space, form-feed ('\f'), newline ('\n'), carriage return('\r'), horizontal tab ('\t'), and vertical tab ('\v').	The character to test	0 if the character tests false and 1 if the character tests true

ft_capitalize

char *ft_capitalize(char *s)

Description	Param. #1	Return Value
Capitalizes the first letter of every word in a string	The string to capitalize	The new string with capitalized words

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