TOLOWER(3) (simplified)
NAME
tolower -- upper case to lower case letter conversion
SYNOPSIS
int tolower(int c);
DESCRIPTION
The tolower() function converts an upper-case letter to the corresponding lower-case letter. The argument must be representable as an unsigned char or the value of EOF.
RETURN VALUES
If the argument is an upper-case letter, the tolower() function returns the corresponding lower-case letter if there is one; otherwise, the argument is returned unchanged.
Understandable explanation
I don't think I'll need to explain with more details what this function does, the man is pretty self-explanatory on this point.
Hints
ft_tolower.c
intft_tolower(int c){if (/* c is an upper-case letter */)return (/* corresponding lower-case letter */);return (c);}
Commented solution
ft_tolower
ft_tolower.c
#include"libft.h"intft_tolower(int c){ /* this checks if the character is an upper-case letter * with the decimal ASCII values (65 => A; 90 => Z) */if (c >=65&& c <=90) /* In the ASCII table, upper-case letters are indexed 32 * less than lower-case letters, so to get the * corresponding lower-case letter, we add 32 to the * upper-case letter */return (c +32); /* As said in the man, if the character is not an upper-case * letter, the argument is returned unchanged, that's why we * return c directly */return (c);}