xref: /csrg-svn/usr.sbin/sendmail/src/macro.c (revision 3387)

# include "useful.h"

static char SccsId[] = "@(#)macro.c	1.2	03/28/81";

char	*Macro[128];
extern bool	Debug;

/*
**  EXPAND -- macro expand a string using $x escapes.
**
**	Parameters:
**		s -- the string to expand.
**		buf -- the place to put the expansion.
**		buflim -- the buffer limit, i.e., the address
**			of the last usable position in buf.
**
**	Returns:
**		buf.
**
**	Side Effects:
**		none.
*/

char *
expand(s, buf, buflim)
	register char *s;
	register char *buf;
	char *buflim;
{
	register char *q;
	register char *bp;
	bool skipping;

# ifdef DEBUG
	if (Debug)
		printf("expand(%s)\n", s);
# endif DEBUG

	skipping = FALSE;
	for (bp = buf; *s != '\0'; s++)
	{
		/* q will be the interpolated quantity */
		q = NULL;
		if (*s == '$')
		{
			char c;

			c = *++s;
			switch (c)
			{
			  case '?':	/* see if var set */
				c = *++s;
				skipping = Macro[c] == NULL;
				break;

			  case ':':	/* else */
				skipping = !skipping;
				break;

			  case '.':	/* end if */
				skipping = FALSE;
				break;

			  default:
				q = Macro[c & 0177];
				break;
			}
			if (q == NULL)
				continue;
		}

		/*
		**  Interpolate q or output one character
		*/

		if (skipping)
			continue;
		if (q != NULL)
			bp = expand(q, bp, buflim);
		else if (bp < buflim - 1)
			*bp++ = *s;
	}
	*bp = '\0';

# ifdef DEBUG
	if (Debug)
		printf("expand ==> '%s'\n", buf);
# endif DEBUG

	return (bp);
}
/*
**  DEFINE -- define a macro.
**
**	this would be better done using a #define macro.
**
**	Parameters:
**		n -- the macro name.
**		v -- the macro value.
**
**	Returns:
**		none.
**
**	Side Effects:
**		Macro[n] is defined.
*/

define(n, v)
	char n;
	char *v;
{
# ifdef DEBUG
	if (Debug)
		printf("define(%c as %s)\n", n, v);
# endif DEBUG
	Macro[n & 0177] = v;
}