#define clrscr() 100

main()

{

clrscr();

printf( "%dn", clrscr() );

}

When atoi() tries to convert argv[0] to a number it cannot do so (argv[0] being a file name) and hence returns a zero.

C: \SAMPLE.EXE

The last line from the file "trial" would be read twice. To avoid this, ues:

       While ( fgets (str, 80, fp) ! = NULL)

               puts (str);

EOF has been defined as #define EOF -1 n the file "stdio.h" and an unsigned char ranges from 0 to 255 hence when EOF is read from the file it cannot be accommodated in ch. Solution is to declare ch as an int.

struct emp

{

     char n[20];

      int age;

};

main()

{

    struct emp e1 = {"Dravid", 23};

   struct emp e2;

   scanf ("%s %d",e2.n, & e2.age);

   if( structcmp (e1,e2) ==0)

        printf ("The structures are equal");

   else

         printf ("The structures are unequal");

}

structcmp ( struct emp x, struct emp y)

{

     if (strcmp (x.n,y.n) ==0)

           if (x.age == y.age)

            return (0);

            return (1);

}

In short, if you nee to compare two structures, you'll have to write your own function to do so which carries out the comparison field by field.

DRAVID

When a structure is assigned, passed, or returned, the copying is done monolithically. This means that the copies of any pointer fields will point to the same place as the original. In other words, anything pointed to is not copied. Hence, on changing the name through e2.n it automatically changed e1.n

No, since the structure contains a char pointer while writing the structure to the disk using fwrite() only the value stored in the pointer n would get written. When this structure is read back the address would be read back but it is quite unlikely that the desired string would be present at this address in memory

A typedef defines a new name for a type, and in simpler cases like the one shown below you can define a new structure type and a typedef for it at the same time.

typedef struct

{

    char name[20];

    int age;

} emp;

However, in the structure defined in this question, there is an error because a typedef declaration cannot be used until it is defined. In the given code fragment the typedef declaration is not yet defined at he point where the link field is declared.