string and malloc

[vei]

I am trying to figure out how to take in a couple strings, then store them into a place in memory, then call that memory and put into a function, so that it can print all strings, I believe this is how malloc is used
thanx vry

[biosx]

Here is a trivial example:

#include <stdio.h>
#include <stdlib.h>

void put_string(char *s);

main()
{ 
    char *c;

    c = (char *)malloc(20 * sizeof(char));

    printf("Enter String: ");
    gets(c);

    printf("The string you entered was:\n");
    put_string(c);

    system("PAUSE");
    return 0;
}

void put_string(char *s) {

     while (*s != '\0')
           printf("%c", *s++);

     printf("\n");
}

This is a trivial example in which you can do so many different ways. I just chose a quick way.

I include <stdlib.h> for the use of the malloc() & system() functions, <stdio.h> for printf(), gets(), etc..

char *c;
c = (char *)malloc(20 * sizeof(char));

This is how malloc() works. It first allocates an amount of memory specified, in this case: 20 units the size of a char. Then malloc returns a pointer to that space created. You then must type-cast the pointer returned to (char *) b/c since you used sizeof() it will return a type of size_t.

Then gets() is a handy function that takes in characters until it has found a newline ('\n') character. It then stores that string (minus the '\n') into a pointer.

Then our makeshift put_string() function is simple. Just write a function that takes a character pointer argument and then walk along the string printing each character in the string. Then printf() a '\n' and voila.

NOTE: There is a function in the C standard library called puts() that does the exact same thing has our makeshift put_string.

Have fun and I hoped this helped.