xref: /titanic_41/usr/src/cmd/sgs/libconv/common/c_literal.c (revision 9a0e82381c494d655823a54fc713a8c2a571131c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 
28 /*
29  * Translate a string into C literal string constant notation.
30  */
31 
32 #include	<stdio.h>
33 #include	<ctype.h>
34 #include	<_conv.h>
35 #include	<c_literal_msg.h>
36 
37 
38 /*
39  * Convert characters to the form used by the C language to represent
40  * literal strings:
41  *	- Printable characters are shown as themselves
42  *	- Convert special characters to their 2-character escaped forms:
43  *		alert (bell)	\a
44  *		backspace	\b
45  *		formfeed	\f
46  *		newline		\n
47  *		return		\r
48  *		horizontal tab	\t
49  *		vertical tab	\v
50  *		backspace	\\
51  *		single quote	\'
52  *		double quote	\"
53  *	- Display other non-printable characters as 4-character escaped
54  *		octal constants.
55  *
56  * entry:
57  *	buf - Buffer of characters to be processed
58  *	n # of characters in buf to be processed
59  *	outfunc - Function to be called to move output characters.
60  *	uvalue - User value. This argument is passed to outfunc without
61  *		examination. The caller can use it to pass additional
62  *		information required by the callback.
63  *
64  * exit:
65  *	The string has been processed, with the resulting data passed
66  *	to outfunc for processing.
67  */
68 void
69 conv_str_to_c_literal(const char *buf, size_t n,
70     Conv_str_to_c_literal_func_t *outfunc, void *uvalue)
71 {
72 	char	bs_buf[2];	/* For two-character backslash codes */
73 	char	octal_buf[10];	/* For \000 style octal constants */
74 
75 	bs_buf[0] = '\\';
76 	while (n > 0) {
77 		switch (*buf) {
78 		case '\0':
79 			bs_buf[1] = '0';
80 			break;
81 		case '\a':
82 			bs_buf[1] = 'a';
83 			break;
84 		case '\b':
85 			bs_buf[1] = 'b';
86 			break;
87 		case '\f':
88 			bs_buf[1] = 'f';
89 			break;
90 		case '\n':
91 			bs_buf[1] = 'n';
92 			break;
93 		case '\r':
94 			bs_buf[1] = 'r';
95 			break;
96 		case '\t':
97 			bs_buf[1] = 't';
98 			break;
99 		case '\v':
100 			bs_buf[1] = 'v';
101 			break;
102 		case '\\':
103 			bs_buf[1] = '\\';
104 			break;
105 		case '\'':
106 			bs_buf[1] = '\'';
107 			break;
108 		case '"':
109 			bs_buf[1] = '"';
110 			break;
111 		default:
112 			bs_buf[1] = '\0';
113 		}
114 
115 		if (bs_buf[1] != '\0') {
116 			(*outfunc)(bs_buf, 2, uvalue);
117 			buf++;
118 			n--;
119 		} else if (isprint(*buf)) {
120 			/*
121 			 * Output the entire sequence of printable
122 			 * characters in a single shot.
123 			 */
124 			const char	*start = buf;
125 			size_t		outlen = 0;
126 
127 			for (start = buf; (n > 0) && isprint(*buf); buf++, n--)
128 				outlen++;
129 			(*outfunc)(start, outlen, uvalue);
130 		} else {
131 			/* Generic unprintable character: Use octal notation */
132 			(void) snprintf(octal_buf, sizeof (octal_buf),
133 			    MSG_ORIG(MSG_FMT_OCTCONST), (uchar_t)*buf);
134 			(*outfunc)(octal_buf, strlen(octal_buf), uvalue);
135 			buf++;
136 			n--;
137 		}
138 	}
139 }
140