str_capitalizer

Subject

Assignment name  : str_capitalizer
Expected files   : str_capitalizer.c
Allowed functions: write
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Write a program that takes one or several strings and, for each argument,
capitalizes the first character of each word (If it's a letter, obviously),
puts the rest in lowercase, and displays the result on the standard output,
followed by a \n.

A "word" is defined as a part of a string delimited either by spaces/tabs, or
by the start/end of the string. If a word only has one letter, it must be
capitalized.

If there are no arguments, the progam must display \n.

Example:

$> ./str_capitalizer | cat -e
$
$> ./str_capitalizer "a FiRSt LiTTlE TESt" | cat -e
A First Little Test$
$> ./str_capitalizer "__SecONd teST A LITtle BiT   Moar comPLEX" "   But... This iS not THAT COMPLEX" "     Okay, this is the last 1239809147801 but not    the least    t" | cat -e
__second Test A Little Bit   Moar Complex$
   But... This Is Not That Complex$
     Okay, This Is The Last 1239809147801 But Not    The Least    T$
$>

Commented solution

str_capitalizer

str_capitalizer.c

#include <unistd.h>

int ft_isspace(char c)
{
    if (c <= 32)
        return (1);
    return (0);
}

void ft_putchar(char c)
{
    write(1, &c, 1);
}

void capitalizer(char *s)
{
    int i = 0;
    while (s[i])
    {
         // If the character is uppercase, make it lowercase
         if (s[i] >= 'A' && s[i] <= 'Z')
             s[i] += 32;
         // Now check for lowercase character and if the previous char
         // is a space character, make it uppercase again
         if ((s[i] >= 'a' && s[i] <= 'z') && ft_isspace(s[i - 1]))
             s[i] -= 32;
         // Now print every char
         ft_putchar(s[i++]);
    }
}

int main(int ac, char **av)
{
    int i = 1;
    if (ac == 1)
        ft_putchar('\n');
    else
    {
        // Loop over all params starting at 1 (we don't want the name of
        // the executable to be written to the screen)
        while (i < ac)
        {
            capitalizer(av[i]);
            ft_putchar('\n');
            i++;
        } 
    }
}