runner% cat params.c
/* params.c: test 3 ways for a function to give a value */
/*   to a string */
/* Written by NR Wagner, 3 Mar 1997 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void  f1(char *word);
char *f2(void);
void  f3(char **wordptr);

void main(void)
{
   char word1[20];
   char *word2;
   char *word3;
   f1(word1);
   printf("1st method: ""%s""\n", word1);
   word2 = f2();
   printf("2nd method: ""%s""\n", word2);
   f3(&word3);
   printf("3rd method: ""%s""\n", word3);
}

/* f1: caller supplies storage */
/*     function inserts characters. */
void  f1(char *word)
{
   strcpy(word, "Alferd Packer");
}

/* f2: caller supplies pointer to char */
/*     function allocates storage, inserts chars, */
/*     and returns pointer to the storage. */
char *f2(void)
{
   char * word;
   word = (char *) malloc(20);
   strcpy(word, "Alf Landon");
   return word;
}

/* f3: caller supplies pointer to string */
/*     function allocates storage, inserts chars, */
/*     and returns pointer to the storage via the  */
/*     parameter. */
void  f3(char **wordptr)
{
   char *word;
   word = (char *) malloc(20);
   strcpy(word, "Alfred E. Newman");
   *wordptr = word;
}


runner% lint -m -u params.c

function returns value which is always ignored
    strcpy              printf          
runner% cc -o parmas params.c
runner% params
1st method: Alferd Packer
2nd method: Alf Landon
3rd method: Alfred E. Newman
runner%