xref: /freebsd/stand/common/interp.c (revision a64729f5077d77e13b9497cb33ecb3c82e606ee8)
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 	 * $Interpreter:4th string that userboot may use to determine that
60 	 * we need to switch interpreters.
61 	 */
62 	interp_identifier = bootprog_interp;
63 	interp_preinit();
64 	interp_init();
65 
66 	printf("\n");
67 
68 	/*
69 	 * Before interacting, we might want to autoboot.
70 	 */
71 	autoboot_maybe();
72 
73 	/*
74 	 * Not autobooting, go manual
75 	 */
76 	printf("\nType '?' for a list of commands, 'help' for more detailed help.\n");
77 	if (getenv("prompt") == NULL)
78 		setenv("prompt", "${interpret}", 1);
79 	if (getenv("interpret") == NULL)
80 		setenv("interpret", "OK", 1);
81 
82 	for (;;) {
83 		input[0] = '\0';
84 		interp_emit_prompt();
85 		ngets(input, sizeof(input));
86 #ifdef LOADER_VERIEXEC
87 		/* some settings should be restritcted */
88 		ve_status_set(-1, VE_UNVERIFIED_OK);
89 #endif
90 		interp_run(input);
91 	}
92 }
93 
94 /*
95  * Read commands from a file, then execute them.
96  *
97  * We store the commands in memory and close the source file so that the media
98  * holding it can safely go away while we are executing.
99  *
100  * Commands may be prefixed with '@' (so they aren't displayed) or '-' (so
101  * that the script won't stop if they fail).
102  */
103 COMMAND_SET(include, "include", "read commands from a file", command_include);
104 
105 static int
106 command_include(int argc, char *argv[])
107 {
108 	int		i;
109 	int		res;
110 	char		**argvbuf;
111 
112 	/*
113 	 * Since argv is static, we need to save it here.
114 	 */
115 	argvbuf = (char**) calloc((u_int)argc, sizeof(char*));
116 	for (i = 0; i < argc; i++)
117 		argvbuf[i] = strdup(argv[i]);
118 
119 	res=CMD_OK;
120 	for (i = 1; (i < argc) && (res == CMD_OK); i++)
121 		res = interp_include(argvbuf[i]);
122 
123 	for (i = 0; i < argc; i++)
124 		free(argvbuf[i]);
125 	free(argvbuf);
126 
127 	return(res);
128 }
129 
130 /*
131  * Emit the current prompt; use the same syntax as the parser
132  * for embedding environment variables. Does not accept input.
133  */
134 void
135 interp_emit_prompt(void)
136 {
137 	char		*pr, *p, *cp, *ev;
138 
139 	if ((cp = getenv("prompt")) == NULL)
140 		cp = ">";
141 	pr = p = strdup(cp);
142 
143 	while (*p != 0) {
144 		if ((*p == '$') && (*(p+1) == '{')) {
145 			for (cp = p + 2; (*cp != 0) && (*cp != '}'); cp++)
146 				;
147 			*cp = 0;
148 			ev = getenv(p + 2);
149 
150 			if (ev != NULL)
151 				printf("%s", ev);
152 			p = cp + 1;
153 			continue;
154 		}
155 		putchar(*p++);
156 	}
157 	putchar(' ');
158 	free(pr);
159 }
160 
161 static struct bootblk_command *
162 interp_lookup_cmd(const char *cmd)
163 {
164 	struct bootblk_command	**cmdp;
165 
166 	/* search the command set for the command */
167 	SET_FOREACH(cmdp, Xcommand_set) {
168 		if (((*cmdp)->c_name != NULL) && !strcmp(cmd, (*cmdp)->c_name))
169 			return (*cmdp);
170 	}
171 	return (NULL);
172 }
173 
174 /*
175  * Perform a builtin command
176  */
177 int
178 interp_builtin_cmd(int argc, char *argv[])
179 {
180 	int			result;
181 	struct bootblk_command	*cmd;
182 
183 	if (argc < 1)
184 		return (CMD_OK);
185 
186 	/* set return defaults; a successful command will override these */
187 	command_errmsg = command_errbuf;
188 	strcpy(command_errbuf, "no error message");
189 	result = CMD_ERROR;
190 
191 	cmd = interp_lookup_cmd(argv[0]);
192 	if (cmd != NULL && cmd->c_fn) {
193 		TSENTER2(argv[0]);
194 		result = cmd->c_fn(argc, argv);
195 		TSEXIT();
196 	} else {
197 		command_errmsg = "unknown command";
198 	}
199 	return (result);
200 }
201 
202 /*
203  * Return true if the builtin command exists
204  */
205 bool
206 interp_has_builtin_cmd(const char *cmd)
207 {
208 	return (interp_lookup_cmd(cmd) != NULL);
209 }
210