I get error on my source code: "invalid initializer". What am I doing wrong? Someone can help me to resolve this please ?
The errors: 
main.c: In function 'main': 
main.c:10:8: error: invalid initializer
Thank's for your help : )
EDIT: my program crash when i'm starting it
#include <unistd.h>
#include <stdio.h>
void    ft_putchar(char const c);
char    *ft_strrev(char *str);
void    ft_swap(char *a, char *b);
int     main()
{  
    char *nom;
        nom = ft_strrev("Linsap");
    printf("%s", nom);
    return (0);
}
void    ft_putchar(char const c)
{
    write(1, &c, 1);
}
char    *ft_strrev(char *str)
{
    int longueur;
    longueur = 0;
    while (str[longueur] != '\0')
    {
        ++longueur;
    }
    int i;
    i = 0;
    for (i = 0; i < longueur; ++i)
    {
        ft_swap(&str[i], &str[--longueur]);
    }
    return str;
}
void    ft_swap(char *a, char *b)
{
    char    tmp;
    tmp = *a;
    *a = *b;
    *b = tmp;  
}