2 * Copyright (c) 1993, David Greenman
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/sysproto.h>
33 #include <sys/imgact.h>
34 #include <sys/kernel.h>
36 #if BYTE_ORDER == LITTLE_ENDIAN
37 #define SHELLMAGIC 0x2123 /* #! */
39 #define SHELLMAGIC 0x2321
42 #define MAXSHELLCMDLEN 64
44 static int exec_shell_imgact __P((struct image_params *imgp));
47 * Shell interpreter image activator. A interpreter name beginning
48 * at imgp->stringbase is the minimal successful exit requirement.
51 exec_shell_imgact(imgp)
52 struct image_params *imgp;
54 const char *image_header = imgp->image_header;
55 const char *ihp, *line_endp;
59 if (((const short *) image_header)[0] != SHELLMAGIC)
63 * Don't allow a shell script to be the shell for a shell
66 if (imgp->interpreted)
69 imgp->interpreted = 1;
72 * Copy shell name and arguments from image_header into string
77 * Find end of line; return if the line > MAXSHELLCMDLEN long.
79 for (ihp = &image_header[2]; *ihp != '\n' && *ihp != '#'; ++ihp) {
80 if (ihp >= &image_header[MAXSHELLCMDLEN])
85 /* reset for another pass */
86 ihp = &image_header[2];
88 /* Skip over leading spaces - until the interpreter name */
89 while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
91 /* copy the interpreter name */
92 interp = imgp->interpreter_name;
93 while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
97 /* Disallow a null interpreter filename */
98 if (*imgp->interpreter_name == '\0')
101 /* reset for another pass */
102 ihp = &image_header[2];
104 /* copy the interpreter name and arguments */
105 while (ihp < line_endp) {
106 /* Skip over leading spaces */
107 while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
109 if (ihp < line_endp) {
111 * Copy to end of token. No need to watch stringspace
112 * because this is at the front of the string buffer
113 * and the maximum shell command length is tiny.
115 while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
116 *imgp->stringp++ = *ihp++;
120 *imgp->stringp++ = 0;
127 imgp->argv0 = imgp->uap->fname;
133 * Tell kern_execve.c about it, with a little help from the linker.
135 static struct execsw shell_execsw = { exec_shell_imgact, "#!" };
136 EXEC_SET(shell, shell_execsw);