xref: /freebsd/stand/common/interp.c (revision 7cd22ac43418da08448d0bab1009ff3cbda85120)
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 	TSENTER();
52 
53 	/*
54 	 * Because interp_identifier is volatile, it cannot be optimized out by
55 	 * the compiler as it's considered an externally observable event.  This
56 	 * prevents the compiler from optimizing out our carefully placed
57 	 * $Interpreter:4th string that userboot may use to determine that
58 	 * we need to switch interpreters.
59 	 */
60 	interp_identifier = bootprog_interp;
61 	interp_init();
62 
63 	printf("\n");
64 
65 	/*
66 	 * Before interacting, we might want to autoboot.
67 	 */
68 	autoboot_maybe();
69 
70 	/*
71 	 * Not autobooting, go manual
72 	 */
73 	printf("\nType '?' for a list of commands, 'help' for more detailed help.\n");
74 	if (getenv("prompt") == NULL)
75 		setenv("prompt", "${interpret}", 1);
76 	if (getenv("interpret") == NULL)
77 		setenv("interpret", "OK", 1);
78 
79 	for (;;) {
80 		input[0] = '\0';
81 		interp_emit_prompt();
82 		ngets(input, sizeof(input));
83 		interp_run(input);
84 	}
85 }
86 
87 /*
88  * Read commands from a file, then execute them.
89  *
90  * We store the commands in memory and close the source file so that the media
91  * holding it can safely go away while we are executing.
92  *
93  * Commands may be prefixed with '@' (so they aren't displayed) or '-' (so
94  * that the script won't stop if they fail).
95  */
96 COMMAND_SET(include, "include", "read commands from a file", command_include);
97 
98 static int
99 command_include(int argc, char *argv[])
100 {
101 	int		i;
102 	int		res;
103 	char		**argvbuf;
104 
105 	/*
106 	 * Since argv is static, we need to save it here.
107 	 */
108 	argvbuf = (char**) calloc((u_int)argc, sizeof(char*));
109 	for (i = 0; i < argc; i++)
110 		argvbuf[i] = strdup(argv[i]);
111 
112 	res=CMD_OK;
113 	for (i = 1; (i < argc) && (res == CMD_OK); i++)
114 		res = interp_include(argvbuf[i]);
115 
116 	for (i = 0; i < argc; i++)
117 		free(argvbuf[i]);
118 	free(argvbuf);
119 
120 	return(res);
121 }
122 
123 /*
124  * Emit the current prompt; use the same syntax as the parser
125  * for embedding environment variables. Does not accept input.
126  */
127 void
128 interp_emit_prompt(void)
129 {
130 	char		*pr, *p, *cp, *ev;
131 
132 	if ((cp = getenv("prompt")) == NULL)
133 		cp = ">";
134 	pr = p = strdup(cp);
135 
136 	while (*p != 0) {
137 		if ((*p == '$') && (*(p+1) == '{')) {
138 			for (cp = p + 2; (*cp != 0) && (*cp != '}'); cp++)
139 				;
140 			*cp = 0;
141 			ev = getenv(p + 2);
142 
143 			if (ev != NULL)
144 				printf("%s", ev);
145 			p = cp + 1;
146 			continue;
147 		}
148 		putchar(*p++);
149 	}
150 	putchar(' ');
151 	free(pr);
152 }
153 
154 /*
155  * Perform a builtin command
156  */
157 int
158 interp_builtin_cmd(int argc, char *argv[])
159 {
160 	int			result;
161 	struct bootblk_command	**cmdp;
162 	bootblk_cmd_t		*cmd;
163 
164 	if (argc < 1)
165 		return(CMD_OK);
166 
167 	/* set return defaults; a successful command will override these */
168 	command_errmsg = command_errbuf;
169 	strcpy(command_errbuf, "no error message");
170 	cmd = NULL;
171 	result = CMD_ERROR;
172 
173 	/* search the command set for the command */
174 	SET_FOREACH(cmdp, Xcommand_set) {
175 		if (((*cmdp)->c_name != NULL) && !strcmp(argv[0], (*cmdp)->c_name))
176 			cmd = (*cmdp)->c_fn;
177 	}
178 	if (cmd != NULL) {
179 		result = (cmd)(argc, argv);
180 	} else {
181 		command_errmsg = "unknown command";
182 	}
183 	return(result);
184 }
185