[Courses] [C]Warnings? (Spoiler on Ex 7-1)

[Michelle Murrain]

Ok, so I'm blithely going along, rather far behind, now (still on chapter 
7, but valiantly trying to finish chapter 9 by Friday, hah!).

I finished assignment 7-1, and I have a question. First, the code:

/*******************************************************************
  *                                                                 *
  *       An English to Metric Conversion Program                   *
  *       To convert various English units to Metric                *
  *                                                                 *
  *  Usage: Enter in the number and the english unit                *
  *  The result in metric units will be printed                     *
  *                                                                 *
  *******************************************************************/

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

float value; /* the number that the user enters*/
char english[12]; /* the name of the english unit */
char metric[12]; /* the name of the metric unit*/
float result; /*the result of the calculation*/
char line[40];
int main ()
{

   printf("Allowable English 
Units:inches,feet,yards,miles,quarts,gallons\n\n");

   while (1)
     {

       /* get the number and the unit from the user*/
       printf("Enter in number and unit:");
       fgets(line, sizeof(line),stdin);
       sscanf(line, "%f %s",&value,&english);

       /* figure out what english unit it is, and what to do with it*/

       if (strcmp(english,"inches")==0) { /* we will convert to centimeters*/
         result = value*2.54;
         strcpy(metric, "centimeters");
       } else if (strcmp(english,"feet")==0) { /* we will convert to meters */
         result = value*.305;
         strcpy(metric,"meters");
       } else if (strcmp(english,"yards")==0) { /* convert to meters */
         result = value*.9144;
         strcpy(metric,"meters");
       } else if (strcmp(english,"miles")==0) { /* convert to kilometers*/
         result = value*1.61;
         strcpy(metric,"kilometers");
       } else if (strcmp(english,"quarts")==0) { /* convert to liters */
         result = value*(3.79/4);
         strcpy(metric,"liters");
       } else if (strcmp(english,"gallons")==0) { /* convert to liters, too */
         result = value*3.79;
         strcpy(metric, "liters");
       } else { /* not a valid english unit */
         printf ("Sorry - not a valid english unit!\n");
         continue;
       }

       printf("%f %s is %f %s\n",value,english,result,metric);
     }
}

Now the question. I get three warnings when I compile this:

eng_to_metr.c: In function `main':
eng_to_metr.c:30: warning: char format, different type arg (arg 4)
eng_to_metr.c:34: warning: implicit declaration of function `strcmp'
eng_to_metr.c:36: warning: implicit declaration of function `strcpy'

What do these mean?

.Michelle

---------------------------------------
Michelle Murrain
tech at murrain.net
AIM/Yahoo Messenger:pearlbear0
http://www.murrain.net/ for pgp public key