int gettok()

in tools/dev/awk/lex.c [101:162]

• 59 lines of code
• 22 McCabe index (conditional complexity)

int gettok(char **pbuf, int *psz)	/* get next input token */
{
	int c, retc;
	char *buf = *pbuf;
	int sz = *psz;
	char *bp = buf;

	c = input();
	if (c == 0)
		return 0;
	buf[0] = c;
	buf[1] = 0;
	if (!isalnum(c) && c != '.' && c != '_')
		return c;

	*bp++ = c;
	if (isalpha(c) || c == '_') {	/* it's a varname */
		for ( ; (c = input()) != 0; ) {
			if (bp-buf >= sz)
				if (!adjbuf(&buf, &sz, bp-buf+2, 100, &bp, "gettok"))
					FATAL( "out of space for name %.10s...", buf );
			if (isalnum(c) || c == '_')
				*bp++ = c;
			else {
				*bp = 0;
				unput(c);
				break;
			}
		}
		*bp = 0;
		retc = 'a';	/* alphanumeric */
	} else {	/* maybe it's a number, but could be . */
		char *rem;
		/* read input until can't be a number */
		for ( ; (c = input()) != 0; ) {
			if (bp-buf >= sz)
				if (!adjbuf(&buf, &sz, bp-buf+2, 100, &bp, "gettok"))
					FATAL( "out of space for number %.10s...", buf );
			if (isdigit(c) || c == 'e' || c == 'E' 
			  || c == '.' || c == '+' || c == '-')
				*bp++ = c;
			else {
				unput(c);
				break;
			}
		}
		*bp = 0;
		strtod(buf, &rem);	/* parse the number */
		if (rem == buf) {	/* it wasn't a valid number at all */
			buf[1] = 0;	/* return one character as token */
			retc = buf[0];	/* character is its own type */
			unputstr(rem+1); /* put rest back for later */
		} else {	/* some prefix was a number */
			unputstr(rem);	/* put rest back for later */
			rem[0] = 0;	/* truncate buf after number part */
			retc = '0';	/* type is number */
		}
	}
	*pbuf = buf;
	*psz = sz;
	return retc;
}