xref: /freebsd/stand/common/interp.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
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 const char * volatile	interp_identifier;
43 
44 /*
45  * Interactive mode
46  */
47 void
48 interact(void)
49 {
50 	static char		input[256];		/* big enough? */
51 
52 	TSENTER();
53 
54 	/*
55 	 * Because interp_identifier is volatile, it cannot be optimized out by
56 	 * the compiler as it's considered an externally observable event.  This
57 	 * prevents the compiler from optimizing out our carefully placed
58 	 * $Interpreter:4th string that userboot may use to determine that
59 	 * we need to switch interpreters.
60 	 */
61 	interp_identifier = bootprog_interp;
62 	interp_init();
63 
64 	printf("\n");
65 
66 	/*
67 	 * Before interacting, we might want to autoboot.
68 	 */
69 	autoboot_maybe();
70 
71 	/*
72 	 * Not autobooting, go manual
73 	 */
74 	printf("\nType '?' for a list of commands, 'help' for more detailed help.\n");
75 	if (getenv("prompt") == NULL)
76 		setenv("prompt", "${interpret}", 1);
77 	if (getenv("interpret") == NULL)
78 		setenv("interpret", "OK", 1);
79 
80 	for (;;) {
81 		input[0] = '\0';
82 		interp_emit_prompt();
83 		ngets(input, sizeof(input));
84 		interp_run(input);
85 	}
86 }
87 
88 /*
89  * Read commands from a file, then execute them.
90  *
91  * We store the commands in memory and close the source file so that the media
92  * holding it can safely go away while we are executing.
93  *
94  * Commands may be prefixed with '@' (so they aren't displayed) or '-' (so
95  * that the script won't stop if they fail).
96  */
97 COMMAND_SET(include, "include", "read commands from a file", command_include);
98 
99 static int
100 command_include(int argc, char *argv[])
101 {
102 	int		i;
103 	int		res;
104 	char		**argvbuf;
105 
106 	/*
107 	 * Since argv is static, we need to save it here.
108 	 */
109 	argvbuf = (char**) calloc((u_int)argc, sizeof(char*));
110 	for (i = 0; i < argc; i++)
111 		argvbuf[i] = strdup(argv[i]);
112 
113 	res=CMD_OK;
114 	for (i = 1; (i < argc) && (res == CMD_OK); i++)
115 		res = interp_include(argvbuf[i]);
116 
117 	for (i = 0; i < argc; i++)
118 		free(argvbuf[i]);
119 	free(argvbuf);
120 
121 	return(res);
122 }
123 
124 /*
125  * Emit the current prompt; use the same syntax as the parser
126  * for embedding environment variables. Does not accept input.
127  */
128 void
129 interp_emit_prompt(void)
130 {
131 	char		*pr, *p, *cp, *ev;
132 
133 	if ((cp = getenv("prompt")) == NULL)
134 		cp = ">";
135 	pr = p = strdup(cp);
136 
137 	while (*p != 0) {
138 		if ((*p == '$') && (*(p+1) == '{')) {
139 			for (cp = p + 2; (*cp != 0) && (*cp != '}'); cp++)
140 				;
141 			*cp = 0;
142 			ev = getenv(p + 2);
143 
144 			if (ev != NULL)
145 				printf("%s", ev);
146 			p = cp + 1;
147 			continue;
148 		}
149 		putchar(*p++);
150 	}
151 	putchar(' ');
152 	free(pr);
153 }
154 
155 static struct bootblk_command *
156 interp_lookup_cmd(const char *cmd)
157 {
158 	struct bootblk_command	**cmdp;
159 
160 	/* search the command set for the command */
161 	SET_FOREACH(cmdp, Xcommand_set) {
162 		if (((*cmdp)->c_name != NULL) && !strcmp(cmd, (*cmdp)->c_name))
163 			return (*cmdp);
164 	}
165 	return (NULL);
166 }
167 
168 /*
169  * Perform a builtin command
170  */
171 int
172 interp_builtin_cmd(int argc, char *argv[])
173 {
174 	int			result;
175 	struct bootblk_command	*cmd;
176 
177 	if (argc < 1)
178 		return (CMD_OK);
179 
180 	/* set return defaults; a successful command will override these */
181 	command_errmsg = command_errbuf;
182 	strcpy(command_errbuf, "no error message");
183 	result = CMD_ERROR;
184 
185 	cmd = interp_lookup_cmd(argv[0]);
186 	if (cmd != NULL && cmd->c_fn) {
187 		result = cmd->c_fn(argc, argv);
188 	} else {
189 		command_errmsg = "unknown command";
190 	}
191 	return (result);
192 }
193 
194 /*
195  * Return true if the builtin command exists
196  */
197 bool
198 interp_has_builtin_cmd(const char *cmd)
199 {
200 	return (interp_lookup_cmd(cmd) != NULL);
201 }
202