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.
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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
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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
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26 * $FreeBSD: src/sys/kern/imgact_shell.c,v 1.21.2.2 2001/12/22 01:21:39 jwd Exp $
27 * $DragonFly: src/sys/kern/imgact_shell.c,v 1.2 2003/06/17 04:28:41 dillon Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/sysproto.h>
34 #include <sys/imgact.h>
35 #include <sys/kernel.h>
37 #if BYTE_ORDER == LITTLE_ENDIAN
38 #define SHELLMAGIC 0x2123 /* #! */
40 #define SHELLMAGIC 0x2321
44 * Shell interpreter image activator. A interpreter name beginning
45 * at imgp->stringbase is the minimal successful exit requirement.
48 exec_shell_imgact(imgp)
49 struct image_params *imgp;
51 const char *image_header = imgp->image_header;
52 const char *ihp, *line_endp;
56 if (((const short *) image_header)[0] != SHELLMAGIC)
60 * Don't allow a shell script to be the shell for a shell
63 if (imgp->interpreted)
66 imgp->interpreted = 1;
69 * Copy shell name and arguments from image_header into string
74 * Find end of line; return if the line > MAXSHELLCMDLEN long.
76 for (ihp = &image_header[2]; *ihp != '\n' && *ihp != '#'; ++ihp) {
77 if (ihp >= &image_header[MAXSHELLCMDLEN])
82 /* reset for another pass */
83 ihp = &image_header[2];
85 /* Skip over leading spaces - until the interpreter name */
86 while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
88 /* copy the interpreter name */
89 interp = imgp->interpreter_name;
90 while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
94 /* Disallow a null interpreter filename */
95 if (*imgp->interpreter_name == '\0')
98 /* reset for another pass */
99 ihp = &image_header[2];
101 /* copy the interpreter name and arguments */
102 while (ihp < line_endp) {
103 /* Skip over leading spaces */
104 while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
106 if (ihp < line_endp) {
108 * Copy to end of token. No need to watch stringspace
109 * because this is at the front of the string buffer
110 * and the maximum shell command length is tiny.
112 while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
113 *imgp->stringp++ = *ihp++;
117 *imgp->stringp++ = 0;
124 imgp->argv0 = imgp->uap->fname;
130 * Tell kern_execve.c about it, with a little help from the linker.
132 static struct execsw shell_execsw = { exec_shell_imgact, "#!" };
133 EXEC_SET(shell, shell_execsw);