xref: /freebsd/stand/common/interp.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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 /*
28  * Simple commandline interpreter, toplevel and misc.
29  *
30  * XXX may be obsoleted by BootFORTH or some other, better, interpreter.
31  */
32 
33 #include <stand.h>
34 #include <string.h>
35 #include "bootstrap.h"
36 
37 #ifdef LOADER_VERIEXEC
38 #include <verify_file.h>
39 #endif
40 
41 #define	MAXARGS	20			/* maximum number of arguments allowed */
42 
43 const char * volatile	interp_identifier;
44 
45 /*
46  * Interactive mode
47  */
48 void
49 interact(void)
50 {
51 	static char		input[256];		/* big enough? */
52 
53 	TSENTER();
54 
55 	/*
56 	 * Because interp_identifier is volatile, it cannot be optimized out by
57 	 * the compiler as it's considered an externally observable event.  This
58 	 * prevents the compiler from optimizing out our carefully placed
59 	 * $Interpreter:4th string that userboot may use to determine that
60 	 * we need to switch interpreters.
61 	 */
62 	interp_identifier = bootprog_interp;
63 	interp_init();
64 
65 	printf("\n");
66 
67 	/*
68 	 * Before interacting, we might want to autoboot.
69 	 */
70 	autoboot_maybe();
71 
72 	/*
73 	 * Not autobooting, go manual
74 	 */
75 	printf("\nType '?' for a list of commands, 'help' for more detailed help.\n");
76 	if (getenv("prompt") == NULL)
77 		setenv("prompt", "${interpret}", 1);
78 	if (getenv("interpret") == NULL)
79 		setenv("interpret", "OK", 1);
80 
81 	for (;;) {
82 		input[0] = '\0';
83 		interp_emit_prompt();
84 		ngets(input, sizeof(input));
85 #ifdef LOADER_VERIEXEC
86 		/* some settings should be restritcted */
87 		ve_status_set(-1, VE_UNVERIFIED_OK);
88 #endif
89 		interp_run(input);
90 	}
91 }
92 
93 /*
94  * Read commands from a file, then execute them.
95  *
96  * We store the commands in memory and close the source file so that the media
97  * holding it can safely go away while we are executing.
98  *
99  * Commands may be prefixed with '@' (so they aren't displayed) or '-' (so
100  * that the script won't stop if they fail).
101  */
102 COMMAND_SET(include, "include", "read commands from a file", command_include);
103 
104 static int
105 command_include(int argc, char *argv[])
106 {
107 	int		i;
108 	int		res;
109 	char		**argvbuf;
110 
111 	/*
112 	 * Since argv is static, we need to save it here.
113 	 */
114 	argvbuf = (char**) calloc((u_int)argc, sizeof(char*));
115 	for (i = 0; i < argc; i++)
116 		argvbuf[i] = strdup(argv[i]);
117 
118 	res=CMD_OK;
119 	for (i = 1; (i < argc) && (res == CMD_OK); i++)
120 		res = interp_include(argvbuf[i]);
121 
122 	for (i = 0; i < argc; i++)
123 		free(argvbuf[i]);
124 	free(argvbuf);
125 
126 	return(res);
127 }
128 
129 /*
130  * Emit the current prompt; use the same syntax as the parser
131  * for embedding environment variables. Does not accept input.
132  */
133 void
134 interp_emit_prompt(void)
135 {
136 	char		*pr, *p, *cp, *ev;
137 
138 	if ((cp = getenv("prompt")) == NULL)
139 		cp = ">";
140 	pr = p = strdup(cp);
141 
142 	while (*p != 0) {
143 		if ((*p == '$') && (*(p+1) == '{')) {
144 			for (cp = p + 2; (*cp != 0) && (*cp != '}'); cp++)
145 				;
146 			*cp = 0;
147 			ev = getenv(p + 2);
148 
149 			if (ev != NULL)
150 				printf("%s", ev);
151 			p = cp + 1;
152 			continue;
153 		}
154 		putchar(*p++);
155 	}
156 	putchar(' ');
157 	free(pr);
158 }
159 
160 static struct bootblk_command *
161 interp_lookup_cmd(const char *cmd)
162 {
163 	struct bootblk_command	**cmdp;
164 
165 	/* search the command set for the command */
166 	SET_FOREACH(cmdp, Xcommand_set) {
167 		if (((*cmdp)->c_name != NULL) && !strcmp(cmd, (*cmdp)->c_name))
168 			return (*cmdp);
169 	}
170 	return (NULL);
171 }
172 
173 /*
174  * Perform a builtin command
175  */
176 int
177 interp_builtin_cmd(int argc, char *argv[])
178 {
179 	int			result;
180 	struct bootblk_command	*cmd;
181 
182 	if (argc < 1)
183 		return (CMD_OK);
184 
185 	/* set return defaults; a successful command will override these */
186 	command_errmsg = command_errbuf;
187 	strcpy(command_errbuf, "no error message");
188 	result = CMD_ERROR;
189 
190 	cmd = interp_lookup_cmd(argv[0]);
191 	if (cmd != NULL && cmd->c_fn) {
192 		result = cmd->c_fn(argc, argv);
193 	} else {
194 		command_errmsg = "unknown command";
195 	}
196 	return (result);
197 }
198 
199 /*
200  * Return true if the builtin command exists
201  */
202 bool
203 interp_has_builtin_cmd(const char *cmd)
204 {
205 	return (interp_lookup_cmd(cmd) != NULL);
206 }
207