interp.c revision 38465 
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	$Id$
27 */
28/*
29 * Simple commandline interpreter.
30 *
31 * XXX may be obsoleted by BootFORTH
32 */
33
34#include <stand.h>
35#include <string.h>
36#include "bootstrap.h"
37
38#define	MAXARGS	20			/* maximum number of arguments allowed */
39
40static int	parse(char *buf, int *argcp, char **argvp[]);
41static void	prompt(void);
42/*
43 * Parse the supplied text into argv/argc form.
44 * XXX should perhaps learn about quotes, etc?
45 * XXX can also do alias expansion, variable substitution, etc. here
46 */
47static int
48parse(char *buf, int *argcp, char **argvp[])
49{
50    static int		argc;
51    static char		*argv[MAXARGS], *cp;
52
53    argc = 0;
54    cp = buf;
55    while ((*cp != 0) && (argc < MAXARGS)) {
56	if (isspace(*cp)) {
57	    *(cp++) = 0;
58	} else {
59	    argv[argc++] = cp++;
60	    while ((*cp != 0) && !isspace(*cp))
61		cp++;
62	}
63    }
64    argv[argc] = NULL;
65    /* command too complex */
66    if (argc >= MAXARGS) {
67	printf("too many arguments\n");
68	return(1);
69    }
70    *argcp = argc;
71    *argvp = argv;
72    return(0);
73}
74
75/*
76 * Perform the command
77 */
78static int
79perform(int argc, char *argv[])
80{
81    int				i, result;
82    struct bootblk_command	**cmdp;
83    bootblk_cmd_t		*cmd;
84
85    if (argc < 1)
86	return(CMD_OK);
87
88    /* set return defaults; a successful command will override these */
89    command_errmsg = command_errbuf;
90    strcpy(command_errbuf, "no error message");
91    cmd = NULL;
92    result = CMD_ERROR;
93
94    cmdp = (struct bootblk_command **)Xcommand_set.ls_items;
95    for (i = 0; i < Xcommand_set.ls_length; i++) {
96	if ((cmdp[i]->c_name != NULL) && !strcmp(argv[0], cmdp[i]->c_name))
97	    cmd = cmdp[i]->c_fn;
98    }
99    if (cmd != NULL) {
100	result = (cmd)(argc, argv);
101    } else {
102	command_errmsg = "unknown command";
103    }
104    return(result);
105}
106
107/*
108 * Interactive mode
109 */
110void
111interact(void)
112{
113    char	input[256];			/* big enough? */
114    int		argc;
115    char	**argv;
116
117    for (;;) {
118	input[0] = '\0';
119	prompt();
120	ngets(input, sizeof(input));
121	if (!parse(input, &argc, &argv) &&
122	    (perform(argc, argv) != 0))
123		printf("%s: %s\n", argv[0], command_errmsg);
124    }
125}
126
127/*
128 * Read command from a file
129 */
130COMMAND_SET(source, "source", "read commands from a file", command_source);
131
132static int
133command_source(int argc, char *argv[])
134{
135    int		i;
136
137    for (i = 1; i < argc; i++)
138	source(argv[i]);
139    return(CMD_OK);
140}
141
142void
143source(char *filename)
144{
145    char	input[256];			/* big enough? */
146    int		argc;
147    char	**argv, *cp;
148    int		fd;
149
150    if (((fd = open(filename, O_RDONLY)) == -1)) {
151	printf("can't open '%s': %s\n", filename, strerror(errno));
152    } else {
153	while (fgetstr(input, sizeof(input), fd) > 0) {
154
155	    /* Discard comments */
156	    if (input[0] == '#')
157		continue;
158	    cp = input;
159	    /* Echo? */
160	    if (input[0] == '@') {
161		cp++;
162	    } else {
163		prompt();
164		printf("%s\n", input);
165	    }
166
167	    if (!parse(cp, &argc, &argv) &&
168		(argc > 0) &&
169		(perform(argc, argv) != 0))
170		    printf("%s: %s\n", argv[0], command_errmsg);
171	}
172	close(fd);
173    }
174}
175
176/*
177 * Emit the current prompt; support primitive embedding of
178 * environment variables.
179 * We're a little rude here, modifying the return from getenv().
180 */
181static void
182prompt(void)
183{
184    char	*p, *cp, *ev, c;
185
186    if ((p = getenv("prompt")) == NULL)
187	p = ">";
188
189    while (*p != 0) {
190	if (*p == '$') {
191	    for (cp = p + 1; (*cp != 0) && isalpha(*cp); cp++)
192		;
193	    c = *cp;
194	    *cp = 0;
195	    ev = getenv(p + 1);
196	    *cp = c;
197
198	    if (ev != NULL) {
199		printf(ev);
200		p = cp;
201		continue;
202	    }
203	}
204	putchar(*p++);
205    }
206    putchar(' ');
207}
208