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shquote.c revision 1.5
      1 /* $NetBSD: shquote.c,v 1.5 2003/07/26 19:24:44 salo 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