xref: /freebsd/stand/common/interp.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * Simple commandline interpreter, toplevel and misc.
32  *
33  * XXX may be obsoleted by BootFORTH or some other, better, interpreter.
34  */
35 
36 #include <stand.h>
37 #include <string.h>
38 #include "bootstrap.h"
39 
40 #define	MAXARGS	20			/* maximum number of arguments allowed */
41 
42 /*
43  * Interactive mode
44  */
45 void
46 interact(void)
47 {
48 	static char		input[256];		/* big enough? */
49 	const char * volatile	interp_identifier;
50 
51 	/*
52 	 * Because interp_identifier is volatile, it cannot be optimized out by
53 	 * the compiler as it's considered an externally observable event.  This
54 	 * prevents the compiler from optimizing out our carefully placed
55 	 * $Interpreter:4th string that userboot may use to determine that
56 	 * we need to switch interpreters.
57 	 */
58 	interp_identifier = bootprog_interp;
59 	interp_init();
60 
61 	printf("\n");
62 
63 	/*
64 	 * Before interacting, we might want to autoboot.
65 	 */
66 	autoboot_maybe();
67 
68 	/*
69 	 * Not autobooting, go manual
70 	 */
71 	printf("\nType '?' for a list of commands, 'help' for more detailed help.\n");
72 	if (getenv("prompt") == NULL)
73 		setenv("prompt", "${interpret}", 1);
74 	if (getenv("interpret") == NULL)
75 		setenv("interpret", "OK", 1);
76 
77 	for (;;) {
78 		input[0] = '\0';
79 		interp_emit_prompt();
80 		ngets(input, sizeof(input));
81 		interp_run(input);
82 	}
83 }
84 
85 /*
86  * Read commands from a file, then execute them.
87  *
88  * We store the commands in memory and close the source file so that the media
89  * holding it can safely go away while we are executing.
90  *
91  * Commands may be prefixed with '@' (so they aren't displayed) or '-' (so
92  * that the script won't stop if they fail).
93  */
94 COMMAND_SET(include, "include", "read commands from a file", command_include);
95 
96 static int
97 command_include(int argc, char *argv[])
98 {
99 	int		i;
100 	int		res;
101 	char		**argvbuf;
102 
103 	/*
104 	 * Since argv is static, we need to save it here.
105 	 */
106 	argvbuf = (char**) calloc((u_int)argc, sizeof(char*));
107 	for (i = 0; i < argc; i++)
108 		argvbuf[i] = strdup(argv[i]);
109 
110 	res=CMD_OK;
111 	for (i = 1; (i < argc) && (res == CMD_OK); i++)
112 		res = interp_include(argvbuf[i]);
113 
114 	for (i = 0; i < argc; i++)
115 		free(argvbuf[i]);
116 	free(argvbuf);
117 
118 	return(res);
119 }
120 
121 /*
122  * Emit the current prompt; use the same syntax as the parser
123  * for embedding environment variables. Does not accept input.
124  */
125 void
126 interp_emit_prompt(void)
127 {
128 	char		*pr, *p, *cp, *ev;
129 
130 	if ((cp = getenv("prompt")) == NULL)
131 		cp = ">";
132 	pr = p = strdup(cp);
133 
134 	while (*p != 0) {
135 		if ((*p == '$') && (*(p+1) == '{')) {
136 			for (cp = p + 2; (*cp != 0) && (*cp != '}'); cp++)
137 				;
138 			*cp = 0;
139 			ev = getenv(p + 2);
140 
141 			if (ev != NULL)
142 				printf("%s", ev);
143 			p = cp + 1;
144 			continue;
145 		}
146 		putchar(*p++);
147 	}
148 	putchar(' ');
149 	free(pr);
150 }
151 
152 /*
153  * Perform a builtin command
154  */
155 int
156 interp_builtin_cmd(int argc, char *argv[])
157 {
158 	int			result;
159 	struct bootblk_command	**cmdp;
160 	bootblk_cmd_t		*cmd;
161 
162 	if (argc < 1)
163 		return(CMD_OK);
164 
165 	/* set return defaults; a successful command will override these */
166 	command_errmsg = command_errbuf;
167 	strcpy(command_errbuf, "no error message");
168 	cmd = NULL;
169 	result = CMD_ERROR;
170 
171 	/* search the command set for the command */
172 	SET_FOREACH(cmdp, Xcommand_set) {
173 		if (((*cmdp)->c_name != NULL) && !strcmp(argv[0], (*cmdp)->c_name))
174 			cmd = (*cmdp)->c_fn;
175 	}
176 	if (cmd != NULL) {
177 		result = (cmd)(argc, argv);
178 	} else {
179 		command_errmsg = "unknown command";
180 	}
181 	return(result);
182 }
183