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1 /* ----------------------------------------------------------------------- *
2  *
3  *   Copyright 2004-2009 H. Peter Anvin - All Rights Reserved
4  *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
5  *
6  *   Permission is hereby granted, free of charge, to any person
7  *   obtaining a copy of this software and associated documentation
8  *   files (the "Software"), to deal in the Software without
9  *   restriction, including without limitation the rights to use,
10  *   copy, modify, merge, publish, distribute, sublicense, and/or
11  *   sell copies of the Software, and to permit persons to whom
12  *   the Software is furnished to do so, subject to the following
13  *   conditions:
14  *
15  *   The above copyright notice and this permission notice shall
16  *   be included in all copies or substantial portions of the Software.
17  *
18  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
20  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
22  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
23  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25  *   OTHER DEALINGS IN THE SOFTWARE.
26  *
27  * ----------------------------------------------------------------------- */
28 
29 /*
30  * argv.c
31  *
32  * Parse a single C string into argc and argv (argc is return value.)
33  * memptr points to available memory.
34  */
35 
36 #include <inttypes.h>
37 #include <stddef.h>
38 #include <stdio.h>
39 #include <syslinux/align.h>
40 #include <com32.h>
41 
42 extern char _end[];		/* Symbol created by linker */
43 void *__mem_end = &_end;	/* Global variable for use by malloc() */
44 
__parse_argv(char *** argv,const char * str)45 int __parse_argv(char ***argv, const char *str)
46 {
47     char dummy_argv0[] = "";
48     char *mem = __mem_end;
49     const char *p = str;
50     char *q = mem;
51     char *r;
52     char **arg;
53     int wasspace = 1;
54     int argc = 1;
55 
56     /* First copy the string, turning whitespace runs into nulls */
57     for (p = str;; p++) {
58 	if (*p <= ' ') {
59 	    if (!wasspace) {
60 		wasspace = 1;
61 		*q++ = '\0';
62 	    }
63 	} else {
64 	    if (wasspace) {
65 		argc++;
66 		wasspace = 0;
67 	    }
68 	    *q++ = *p;
69 	}
70 
71 	/* This test is AFTER we have processed the null byte;
72 	   we treat it as a whitespace character so it terminates
73 	   the last argument */
74 	if (!*p)
75 	    break;
76     }
77 
78     /* Now create argv */
79     arg = (char **)ALIGN_UP_FOR(q, char *);
80     *argv = arg;
81     *arg++ = __com32.cs_name ? (char *)__com32.cs_name : dummy_argv0; /* argv[0] */
82 
83     q--;			/* Point q to final null */
84     if (mem < q)
85 	*arg++ = mem;		/* argv[1] */
86 
87     for (r = mem; r < q; r++) {
88 	if (*r == '\0') {
89 	    *arg++ = r + 1;
90 	}
91     }
92 
93     *arg++ = NULL;		/* Null pointer at the end */
94     __mem_end = arg;		/* End of memory we used */
95 
96     return argc;
97 }
98