C-programming autumn 2007

Exercise 1

7.9 12:00-14:00 B119.

1. Write into a file "Hello, world" program, compile and make a runnable program. Run the program.

   #include <stdio.h>
   
   main()
   {
   printf("Hello, world!\n");
   return 0;
   }
   

2. In lecture notes there is a situation, where a program consists of modules (eka, toka, main etc.) Write codes in to files and compile them and make a runnable program from object files. Write also a makefile that does the same and try to use it.
   
   
3. What the following codes of C do?

   a)while (*q++ = *p++);
   b)if ((c=fgetc(fileHandle)) == EOF)
   c)for (i=a, j=b; i<=j; i += 2, j += 2)
   

4. Identify the errors and try to correct them.

   #include <stdio.h>
   int longest(char **p, char *r) {
   char *s,*t;
   int max=0; len;
   while(*p++) {
        if ((len=strlen(*p) > max )  {
             max==len;
             s=*p
        }
        p++;
    }
    t=s;
    whlie(*r++ == *s++);
    r=t;
    return s - t;
   }
   
   int main () {
   int pit;
   char  pisin_rivi(80);
   static char *tptr[5] ={
     "Ensimmäinen \
      rivi",
     "Toinen rivi",
     "Ja tässä kolmas rivi",
     "Neljäs on riveistä kaikkein pisin",
     "Viides ja viimeinen"
    };
   char *pp = pisin_rivi;
   pit= longest(tptr,pp);
   prinft("%d merkkiä: %s\n",pit, pp);
   return 0
   }
   

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