xref: /netbsd-src/lib/libc/gen/shquote.c (revision 1c9b56c830954ccf3b57004ac65562e3d6afacf6)
1 /* $NetBSD: shquote.c,v 1.6 2005/02/09 21:35:46 kleink Exp $ */
2 
3 /*
4  * Copyright (c) 2001 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *          This product includes software developed for the
18  *          NetBSD Project.  See http://www.NetBSD.org/ for
19  *          information about NetBSD.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
35  */
36 
37 /*
38  * Define SHQUOTE_USE_MULTIBYTE if you want shquote() to handle multibyte
39  * characters using mbrtowc().
40  *
41  * Please DO NOT rip this #ifdef out of the code.  It's also here to help
42  * portability.
43  */
44 #undef	SHQUOTE_USE_MULTIBYTE
45 
46 #include "namespace.h"
47 #include <stdlib.h>
48 #include <string.h>
49 #ifdef SHQUOTE_USE_MULTIBYTE
50 #include <limits.h>
51 #include <stdio.h>
52 #include <wchar.h>
53 #endif
54 
55 #ifdef __weak_alias
56 __weak_alias(shquote,_shquote)
57 #endif
58 
59 /*
60  * shquote():
61  *
62  * Requotes arguments so that they'll be interpreted properly by the
63  * shell (/bin/sh).
64  *
65  * Wraps single quotes around the string, and replaces single quotes
66  * in the string with the sequence:
67  *	'\''
68  *
69  * Returns the number of characters required to hold the resulting quoted
70  * argument.
71  *
72  * The buffer supplied is filled in and NUL-terminated.  If 'bufsize'
73  * indicates that the buffer is too short to hold the output string, the
74  * first (bufsize - 1) bytes of quoted argument are filled in and the
75  * buffer is NUL-terminated.
76  *
77  * Changes could be made to optimize the length of strings output by this
78  * function:
79  *
80  *	* if there are no metacharacters or whitespace in the input,
81  *	  the output could be the input string.
82  */
83 
84 #ifdef SHQUOTE_USE_MULTIBYTE
85 
86 #define	XLATE_OUTCH(x)		wcrtomb(outch, (x), &mbso)
87 #define	XLATE_INCH()						\
88     do {							\
89 	n = mbrtowc(&c, arg, MB_CUR_MAX, &mbsi);		\
90     } while (/*LINTED const cond*/0)
91 
92 #else
93 
94 #define	XLATE_OUTCH(x)		(outch[0] = (x), 1)
95 #define	XLATE_INCH()						\
96     do {							\
97 	n = ((c = *arg) != '\0') ? 1 : 0;			\
98     } while (/*LINTED const cond*/0)
99 
100 #endif
101 
102 #define	PUT(x)							\
103     do {							\
104 	outchlen = XLATE_OUTCH(x);				\
105 	if (outchlen == (size_t)-1)				\
106 		goto bad;					\
107 	rv += outchlen;						\
108 	if (bufsize != 0) {					\
109 		if (bufsize < outchlen ||			\
110 		    (bufsize == outchlen &&			\
111 		     outch[outchlen - 1] != '\0')) {		\
112 			*buf = '\0';				\
113 			bufsize = 0;				\
114 		} else {					\
115 			memcpy(buf, outch, outchlen);		\
116 			buf += outchlen;			\
117 			bufsize -= outchlen;			\
118 		}						\
119 	}							\
120     } while (/*LINTED const cond*/0)
121 
122 size_t
123 shquote(const char *arg, char *buf, size_t bufsize)
124 {
125 #ifdef SHQUOTE_USE_MULTIBYTE
126 	char outch[MB_LEN_MAX];
127 	mbstate_t mbsi, mbso;
128 	wchar_t c, lastc;
129 	size_t outchlen;
130 #else
131 	char outch[1];
132 	char c, lastc;
133 	size_t outchlen;
134 #endif
135 	size_t rv;
136 	int n;
137 
138 	rv = 0;
139 	lastc = 0;
140 #ifdef SHQUOTE_USE_MULTIBYTE
141 	memset(&mbsi, 0, sizeof mbsi);
142 	memset(&mbso, 0, sizeof mbso);
143 #endif
144 
145 	if (*arg != '\'')
146 		PUT('\'');
147 	for (;;) {
148 		XLATE_INCH();
149 		if (n == (size_t)-1)
150 			goto bad;
151 		if (n <= 0)
152 			break;
153 		arg += n;
154 		lastc = c;
155 
156 		if (c == '\'') {
157 			if (rv != 0)
158 				PUT('\'');
159 			PUT('\\');
160 			PUT('\'');
161 			for (;;) {
162 				XLATE_INCH();
163 				if (n <= 0 || c != '\'')
164 					break;
165 				PUT('\\');
166 				PUT('\'');
167 				arg += n;
168 			}
169 			if (n > 0)
170 				PUT('\'');
171 		} else
172 			PUT(c);
173 	}
174 	if (lastc != '\'')
175 		PUT('\'');
176 
177 	/* Put multibyte or NUL terminator, but don't count the NUL. */
178 	PUT('\0');
179 	rv--;
180 
181 	return rv;
182 
183 bad:
184 	/* A multibyte character encoding or decoding error occurred. */
185 	return (size_t)-1;
186 }
187