Question

void main() { 
    void strrev(char *); 
    char *p="GOOd";
    strrev(p);
    printf("%s",p);
}

void strrev(char *str) { 
    char temp, *end_ptr;
    if( str == NULL || !(*str) ) return;
    end_ptr = str + strlen(str) - 1;

    while( end_ptr > str ) 
    { 
        temp = *str; 
        *str = *end_ptr; 
        *end_ptr = temp; str++; 
        end_ptr--; 
    } 
}

i am getting the error segmentation failed can any one help me out how to sort it out…

Answer 1

One problem is that in the following:

char *p = "GOOd";

the compiler is allowed to place the string literal in read-only memory.

Any attempt to modify the string pointed to by p results in undefined behaviour.

Try changing the above line to:

char p[] = "GOOd";

I don’t see anything wrong with the strrev() function itself.