xref: /netbsd/lib/libc/gen/shquote.c (revision bf9ec67e)
1 /* $NetBSD: shquote.c,v 1.4 2001/03/12 03:20:10 simonb 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 <stdlib.h>
47 #include <string.h>
48 #ifdef SHQUOTE_USE_MULTIBYTE
49 #include <limits.h>
50 #include <stdio.h>
51 #include <wchar.h>
52 #endif
53 
54 /*
55  * shquote():
56  *
57  * Requotes arguments so that they'll be interpreted properly by the
58  * shell (/bin/sh).
59  *
60  * Wraps single quotes around the string, and replaces single quotes
61  * in the string with the sequence:
62  *	'\''
63  *
64  * Returns the number of characters required to hold the resulting quoted
65  * argument.
66  *
67  * The buffer supplied is filled in and NUL-terminated.  If 'bufsize'
68  * indicates that the buffer is too short to hold the output string, the
69  * first (bufsize - 1) bytes of quoted argument are filled in and the
70  * buffer is NUL-terminated.
71  *
72  * Changes could be made to optimize the length of strings output by this
73  * function:
74  *
75  *	* if there are no metacharacters or whitespace in the input,
76  *	  the output could be the input string.
77  */
78 
79 #ifdef SHQUOTE_USE_MULTIBYTE
80 
81 #define	XLATE_OUTCH(x)		wcrtomb(outch, (x), &mbso)
82 #define	XLATE_INCH()						\
83     do {							\
84 	n = mbrtowc(&c, arg, MB_CUR_MAX, &mbsi);		\
85     } while (/*LINTED const cond*/0)
86 
87 #else
88 
89 #define	XLATE_OUTCH(x)		(outch[0] = (x), 1)
90 #define	XLATE_INCH()						\
91     do {							\
92 	n = ((c = *arg) != '\0') ? 1 : 0;			\
93     } while (/*LINTED const cond*/0)
94 
95 #endif
96 
97 #define	PUT(x)							\
98     do {							\
99 	outchlen = XLATE_OUTCH(x);				\
100 	if (outchlen == (size_t)-1)				\
101 		goto bad;					\
102 	rv += outchlen;						\
103 	if (bufsize != 0) {					\
104 		if (bufsize < outchlen ||			\
105 		    (bufsize == outchlen &&			\
106 		     outch[outchlen - 1] != '\0')) {		\
107 			*buf = '\0';				\
108 			bufsize = 0;				\
109 		} else {					\
110 			memcpy(buf, outch, outchlen);		\
111 			buf += outchlen;			\
112 			bufsize -= outchlen;			\
113 		}						\
114 	}							\
115     } while (/*LINTED const cond*/0)
116 
117 size_t
118 shquote(const char *arg, char *buf, size_t bufsize)
119 {
120 #ifdef SHQUOTE_USE_MULTIBYTE
121 	char outch[MB_LEN_MAX];
122 	mbstate_t mbsi, mbso;
123 	wchar_t c, lastc;
124 	size_t outchlen;
125 #else
126 	char outch[1];
127 	char c, lastc;
128 	size_t outchlen;
129 #endif
130 	size_t rv;
131 	int n;
132 
133 	rv = 0;
134 	lastc = 0;
135 #ifdef SHQUOTE_USE_MULTIBYTE
136 	memset(&mbsi, 0, sizeof mbsi);
137 	memset(&mbso, 0, sizeof mbso);
138 #endif
139 
140 	if (*arg != '\'')
141 		PUT('\'');
142 	for (;;) {
143 		XLATE_INCH();
144 		if (n == (size_t)-1)
145 			goto bad;
146 		if (n <= 0)
147 			break;
148 		arg += n;
149 		lastc = c;
150 
151 		if (c == '\'') {
152 			if (rv != 0)
153 				PUT('\'');
154 			PUT('\\');
155 			PUT('\'');
156 			for (;;) {
157 				XLATE_INCH();
158 				if (n <= 0 || c != '\'')
159 					break;
160 				PUT('\\');
161 				PUT('\'');
162 				arg += n;
163 			}
164 			if (n > 0)
165 				PUT('\'');
166 		} else
167 			PUT(c);
168 	}
169 	if (lastc != '\'')
170 		PUT('\'');
171 
172 	/* Put multibyte or NUL terminator, but don't count the NUL. */
173 	PUT('\0');
174 	rv--;
175 
176 	return rv;
177 
178 bad:
179 	/* A multibyte character encoding or decoding error occurred. */
180 	return (size_t)-1;
181 }
182