xref: /netbsd/sys/arch/i386/stand/lib/crt/dos/doscommain.c (revision 6550d01e)
1 /*	$NetBSD: doscommain.c,v 1.6 2008/12/14 18:46:33 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1996
5  *	Matthias Drochner.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  */
28 
29 /* argument line processing for DOS .COM programs */
30 
31 #include <lib/libsa/stand.h>
32 
33 /* The Program Segment Prefix */
34 
35 static struct psp{
36 	char mist1[0x2c];
37 	short envseg;
38 	char mist2[0x80-2-0x2c];
39 	char cmdlen;
40 	char cmd[127];
41 } *PSP = (struct psp*)0;
42 
43 static char* argv[64]; /* theor max */
44 
45 static int whitespace(char);
46 
47 static int
48 whitespace(char c)
49 {
50 	if ((c == '\0') || (c == ' ') || (c == '\t')
51 	    || (c == '\r') || (c == '\n'))
52 		return (1);
53 	return 0;
54 }
55 
56 enum state {skipping, doing_arg, doing_long_arg};
57 
58 /* build argv/argc, start real main() */
59 int doscommain(void);
60 extern int main(int, char**);
61 
62 int
63 doscommain(void)
64 {
65 	int argc, i;
66 	enum state s;
67 
68 	argv[0] = "???"; /* we don't know */
69 	argc = 1;
70 	s = skipping;
71 
72 	for (i = 0; i < PSP->cmdlen; i++){
73 
74 		if (whitespace(PSP->cmd[i])) {
75 			if (s == doing_arg) {
76 				/* end of argument word */
77 				PSP->cmd[i] = '\0';
78 				s = skipping;
79 			}
80 			continue;
81 		}
82 
83 		if (PSP->cmd[i] == '"') {
84 			/* start or end long arg
85 			 * (end only if next char is whitespace)
86 			 *  XXX but '" ' cannot be in argument
87 			 */
88 			switch (s) {
89 			case skipping:
90 				/* next char begins new argument word */
91 				argv[argc++] = &PSP->cmd[i + 1];
92 				s = doing_long_arg;
93 				break;
94 			case doing_long_arg:
95 				if (whitespace(PSP->cmd[i + 1])) {
96 					PSP->cmd[i] = '\0';
97 					s = skipping;
98 				}
99 			case doing_arg:
100 				/* ignore in the middle of arguments */
101 			default:
102 				break;
103 			}
104 			continue;
105 		}
106 
107 		/* all other characters */
108 		if (s == skipping) {
109 			/* begin new argument word */
110 			argv[argc++] = &PSP->cmd[i];
111 			s = doing_arg;
112 		}
113 	}
114 	if (s != skipping)
115 		PSP->cmd[i] = '\0'; /* to be sure */
116 
117 	/* start real main() */
118 	return main(argc, argv);
119 }
120