Sams Teach Yourself C in 21 Days

17:

18: if (message[count] == ‘\0’)

19: {

20: putchar(‘\n’);

21: break;

22: }

23: else

24:

25: /* If end of string not found, write the next character. */

26:

27: putchar(message[count]);

28: }

29: return 0;

30: }

Displayed with putchar().

Using the putc()andfputc()Functions

Theputc()andfputc()functions perform the same action—sending a single character

to a specified stream. putc()is a macro implementation of fputc(). You’ll learn about

macros on Day 21, “Advanced Compiler Use.” For now, just stick to fputc(). Its proto-

type is

int fputc(int c, FILE *fp);

TheFILE *fppart might puzzle you. You pass fputc()the output stream in this argu-

ment. (You’ll learn more about this on Day 16.) If you specify stdoutas the stream,

fputc()behaves exactly the same as putchar(). Thus, the following two statements are

equivalent:

putchar(‘x’);

fputc(‘x’, stdout);

Usingputs()andfputs()for String Output ..............................................

Your programs display strings on-screen more often than they display single characters.

The library function puts()displays strings. The function fputs()sends a string to a

specified stream; otherwise, it is identical to puts(). The prototype for puts()is

int puts(char *cp);

*cpis a pointer to the first character of the string that you want displayed. The puts()

function displays the entire string up to but not including the terminating null character,

adding a new line at the end. Then puts()returns a positive value if successful or EOFon

error. (Remember,EOFis a symbolic constant with the value -1; it is defined in stdio.h.)

360 Day 14

LISTING14.11 continued

OUTPUT

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