printf function arguments

[tgiri]

hello, this is gireesh.
can u pls give me solution to this question.
PLATFORM : C language
Q. What are the input arguments passed to the printf() function?

actually i found in header file i.e;
extern int printf(const *char, ....);
what is the meaning of .... in printf function?

pls give me reply as early as possible.
my email id : <snipped>

[svlsr2000]

hello, this is gireesh.
can u pls give me solution to this question.
PLATFORM : C language
Q. What are the input arguments passed to the printf() function?

actually i found in header file i.e;
extern int printf(const *char, ....);
what is the meaning of .... in printf function?

pls give me reply as early as possible.
my email id : tgiree@gmail.co m

... is used to get variable length arguments. these arguments are retrieved using some macros and functions declared in stdarg.h
You can have your own print like this

void
miniprintf(const char *fmt, ...)
{
	const char *p;
	int i;
	unsigned u;
	char *s;
	va_list argp;

	va_start(argp, fmt);

	for(p = fmt; *p != '\0'; p++) {
		if(*p != '%') {
			putchar(*p);
			continue;
		}

		switch(*++p) {
		case 'c':
			i = va_arg(argp, int);
			/* *not* va_arg(argp, char); see Q 15.10 */
			putchar(i);
			break;

		case 'd':
			i = va_arg(argp, int);
			if(i < 0) {
				/* XXX won't handle INT_MIN */
				i = -i;
				putchar('-');
			}
			fputs(baseconv(i, 10), stdout);
			break;

		case 'o':
			u = va_arg(argp, unsigned int);
			fputs(baseconv(u, 8), stdout);
			break;

		case 's':
			s = va_arg(argp, char *);
			fputs(s, stdout);
			break;

		case 'u':
			u = va_arg(argp, unsigned int);
			fputs(baseconv(u, 10), stdout);
			break;

		case 'x':
			u = va_arg(argp, unsigned int);
			fputs(baseconv(u, 16), stdout);
			break;

		case '%':
			putchar('%');
			break;
		}
	}

	va_end(argp);
}

Note : This code has been copied from c faq

... is known as ellipsis operator

[Banfa]

... is used to get variable length arguments.

For clarification the arguments are not variable length (it is not possible for arguments to be of variable length). It is the number of arguments that is variable.

... is used to indicated that an unspecified number of extra arguments can be present in the function call.

Functions using the elipsis to indicate a variable number of function arguments are called varidac functions.

[JosAH]

Make that 'variadic' ;-)

kind regards,

Jos