/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"


/*
 * Translate a string into C literal string constant notation.
 */

#include	<stdio.h>
#include	<ctype.h>
#include	<_conv.h>
#include	<c_literal_msg.h>


/*
 * Convert characters to the form used by the C language to represent
 * literal strings:
 *	- Printable characters are shown as themselves
 *	- Convert special characters to their 2-character escaped forms:
 *		alert (bell)	\a
 *		backspace	\b
 *		formfeed	\f
 *		newline		\n
 *		return		\r
 *		horizontal tab	\t
 *		vertical tab	\v
 *		backspace	\\
 *		single quote	\'
 *		double quote	\"
 *	- Display other non-printable characters as 4-character escaped
 *		octal constants.
 *
 * entry:
 *	buf - Buffer of characters to be processed
 *	n # of characters in buf to be processed
 *	outfunc - Function to be called to move output characters.
 *	uvalue - User value. This argument is passed to outfunc without
 *		examination. The caller can use it to pass additional
 *		information required by the callback.
 *
 * exit:
 *	The string has been processed, with the resulting data passed
 *	to outfunc for processing.
 */
void
conv_str_to_c_literal(const char *buf, size_t n,
    Conv_str_to_c_literal_func_t *outfunc, void *uvalue)
{
	char	bs_buf[2];	/* For two-character backslash codes */
	char	octal_buf[10];	/* For \000 style octal constants */

	bs_buf[0] = '\\';
	while (n > 0) {
		switch (*buf) {
		case '\0':
			bs_buf[1] = '0';
			break;
		case '\a':
			bs_buf[1] = 'a';
			break;
		case '\b':
			bs_buf[1] = 'b';
			break;
		case '\f':
			bs_buf[1] = 'f';
			break;
		case '\n':
			bs_buf[1] = 'n';
			break;
		case '\r':
			bs_buf[1] = 'r';
			break;
		case '\t':
			bs_buf[1] = 't';
			break;
		case '\v':
			bs_buf[1] = 'v';
			break;
		case '\\':
			bs_buf[1] = '\\';
			break;
		case '\'':
			bs_buf[1] = '\'';
			break;
		case '"':
			bs_buf[1] = '"';
			break;
		default:
			bs_buf[1] = '\0';
		}

		if (bs_buf[1] != '\0') {
			(*outfunc)(bs_buf, 2, uvalue);
			buf++;
			n--;
		} else if (isprint(*buf)) {
			/*
			 * Output the entire sequence of printable
			 * characters in a single shot.
			 */
			const char	*start = buf;
			size_t		outlen = 0;

			for (start = buf; (n > 0) && isprint(*buf); buf++, n--)
				outlen++;
			(*outfunc)(start, outlen, uvalue);
		} else {
			/* Generic unprintable character: Use octal notation */
			(void) snprintf(octal_buf, sizeof (octal_buf),
			    MSG_ORIG(MSG_FMT_OCTCONST), *buf);
			(*outfunc)(octal_buf, strlen(octal_buf), uvalue);
			buf++;
			n--;
		}
	}
}