1 # include "useful.h"
2 
3 static char SccsId[] = "@(#)macro.c	3.4	09/06/81";
4 
5 char	*Macro[128];
6 extern int	Debug;
7 
8 /*
9 **  EXPAND -- macro expand a string using $x escapes.
10 **
11 **	Parameters:
12 **		s -- the string to expand.
13 **		buf -- the place to put the expansion.
14 **		buflim -- the buffer limit, i.e., the address
15 **			of the last usable position in buf.
16 **
17 **	Returns:
18 **		End of interpolated output.
19 **
20 **	Side Effects:
21 **		none.
22 */
23 
24 char *
25 expand(s, buf, buflim)
26 	register char *s;
27 	register char *buf;
28 	char *buflim;
29 {
30 	register char *bp;
31 	bool skipping;		/* set if conditionally skipping output */
32 
33 # ifdef DEBUG
34 	if (Debug > 3)
35 		printf("expand(%s)\n", s);
36 # endif DEBUG
37 
38 	skipping = FALSE;
39 	for (bp = buf; *s != '\0'; s++)
40 	{
41 		register char *q;
42 
43 		/*
44 		**  Check for non-ordinary (special?) character --
45 		**  always escaped with dollar sign.
46 		**	'q' will be the interpolated quantity.
47 		*/
48 
49 		q = NULL;
50 		if (*s == '$')
51 		{
52 			char c;
53 
54 			c = *++s;
55 			switch (c)
56 			{
57 			  case '?':	/* see if var set */
58 				c = *++s;
59 				skipping = Macro[c] == NULL;
60 				break;
61 
62 			  case ':':	/* else */
63 				skipping = !skipping;
64 				break;
65 
66 			  case '.':	/* end if */
67 				skipping = FALSE;
68 				break;
69 
70 			  default:
71 				q = Macro[c & 0177];
72 				break;
73 			}
74 			if (q == NULL && c != '$')
75 				continue;
76 		}
77 
78 		/*
79 		**  Interpolate q or output one character
80 		*/
81 
82 		if (skipping)
83 			continue;
84 		if (q != NULL)
85 			bp = expand(q, bp, buflim);
86 		else if (bp < buflim - 1)
87 			*bp++ = *s;
88 	}
89 	*bp = '\0';
90 
91 # ifdef DEBUG
92 	if (Debug > 3)
93 		printf("expand ==> '%s'\n", buf);
94 # endif DEBUG
95 
96 	return (bp);
97 }
98 /*
99 **  DEFINE -- define a macro.
100 **
101 **	this would be better done using a #define macro.
102 **
103 **	Parameters:
104 **		n -- the macro name.
105 **		v -- the macro value.
106 **
107 **	Returns:
108 **		none.
109 **
110 **	Side Effects:
111 **		Macro[n] is defined.
112 **
113 **	Notes:
114 **		There is one macro for each ASCII character,
115 **		although they are not all used.  The currently
116 **		defined macros are:
117 **
118 **		$a   date in ARPANET format (preferring the Date: line
119 **		     of the message)
120 **		$b   the current date (as opposed to the date as found
121 **		     the message) in ARPANET format
122 **		$c   hop count
123 **		$d   (current) date in UNIX (ctime) format
124 **		$f   raw from address
125 **		$g   translated from address
126 **		$h   to host
127 **		$l   UNIX-style from line+
128 **		$n   name of sendmail ("MAILER-DAEMON" on local
129 **		     net typically)+
130 **		$o   delimiters ("operators") for address tokens+
131 **		$p   my process id in decimal
132 **		$t   the current time in seconds since 1/1/1970
133 **		$u   to user
134 **		$v   version number of sendmail
135 **		$x   signature (full name) of from person
136 **		$y   the tty id of our terminal
137 **		$z   home directory of to person
138 **
139 **		Macros marked with + must be defined in the
140 **		configuration file and are used internally, but
141 **		are not set.
142 **
143 **		There are also some macros that can be used
144 **		arbitrarily to make the configuration file
145 **		cleaner.  In general all upper-case letters
146 **		are available.
147 */
148 
149 define(n, v)
150 	char n;
151 	char *v;
152 {
153 # ifdef DEBUG
154 	if (Debug > 3)
155 		printf("define(%c as %s)\n", n, v);
156 # endif DEBUG
157 	Macro[n & 0177] = v;
158 }
159