func_sprintf.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005-2006, Digium, Inc.
 * Portions Copyright (C) 2005, Tilghman Lesher. All rights reserved.
 * Portions Copyright (C) 2005, Anthony Minessale II
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief String manipulation dialplan functions
 *
 * \author Tilghman Lesher
 * \author Anothony Minessale II
 * \ingroup functions
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <ctype.h>

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"

AST_THREADSTORAGE(result_buf);

/*** DOCUMENTATION
 <function name="SPRINTF" language="en_US">
 <synopsis>
 Format a variable according to a format string.
 </synopsis>
 <syntax>
 <parameter name="format" required="true" />
 <parameter name="arg1" required="true" />
 <parameter name="arg2" multiple="true" />
 <parameter name="argN" />
 </syntax>
 <description>
 <para>Parses the format string specified and returns a string matching
 that format. Supports most options found in <emphasis>sprintf(3)</emphasis>.
 Returns a shortened string if a format specifier is not recognized.</para>
 </description>
 <see-also>
 <ref type="manpage">sprintf(3)</ref>
 </see-also>
 </function>
 ***/
static int acf_sprintf(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
#define SPRINTF_FLAG 0
#define SPRINTF_WIDTH 1
#define SPRINTF_PRECISION 2
#define SPRINTF_LENGTH 3
#define SPRINTF_CONVERSION 4
 int i, state = -1, argcount = 0;
 char *formatstart = NULL, *bufptr = buf;
 char formatbuf[256] = "";
 int tmpi;
 double tmpd;
 AST_DECLARE_APP_ARGS(arg,
 AST_APP_ARG(format);
 AST_APP_ARG(var)[100];
 );

 AST_STANDARD_APP_ARGS(arg, data);

 /* Scan the format, converting each argument into the requisite format type. */
 for (i = 0; arg.format[i]; i++) {
 switch (state) {
 case SPRINTF_FLAG:
 if (strchr("#0- +'I", arg.format[i]))
 break;
 state = SPRINTF_WIDTH;
 case SPRINTF_WIDTH:
 if (arg.format[i] >= '0' && arg.format[i] <= '9')
 break;

 /* Next character must be a period to go into a precision */
 if (arg.format[i] == '.') {
 state = SPRINTF_PRECISION;
 } else {
 state = SPRINTF_LENGTH;
 i--;
 }
 break;
 case SPRINTF_PRECISION:
 if (arg.format[i] >= '0' && arg.format[i] <= '9')
 break;
 state = SPRINTF_LENGTH;
 case SPRINTF_LENGTH:
 if (strchr("hl", arg.format[i])) {
 if (arg.format[i + 1] == arg.format[i])
 i++;
 state = SPRINTF_CONVERSION;
 break;
 } else if (strchr("Lqjzt", arg.format[i])) {
 state = SPRINTF_CONVERSION;
 break;
 }
 state = SPRINTF_CONVERSION;
 case SPRINTF_CONVERSION:
 if (strchr("diouxXc", arg.format[i])) {
 /* Integer */

 /* Isolate this format alone */
 ast_copy_string(formatbuf, formatstart, sizeof(formatbuf));
 formatbuf[&arg.format[i] - formatstart + 1] = '\0';

 /* Convert the argument into the required type */
 if (arg.var[argcount]) {
 if (sscanf(arg.var[argcount++], "%30d", &tmpi) != 1) {
 ast_log(LOG_ERROR, "Argument '%s' is not an integer number for format '%s'\n", arg.var[argcount - 1], formatbuf);
 goto sprintf_fail;
 }
 } else {
 ast_log(LOG_ERROR, "SPRINTF() has more format specifiers than arguments!\n");
 goto sprintf_fail;
 }

 /* Format the argument */
 snprintf(bufptr, buf + len - bufptr, formatbuf, tmpi);

 /* Update the position of the next parameter to print */
 bufptr = strchr(buf, '\0');
 } else if (strchr("eEfFgGaA", arg.format[i])) {
 /* Double */

 /* Isolate this format alone */
 ast_copy_string(formatbuf, formatstart, sizeof(formatbuf));
 formatbuf[&arg.format[i] - formatstart + 1] = '\0';

 /* Convert the argument into the required type */
 if (arg.var[argcount]) {
 if (sscanf(arg.var[argcount++], "%30lf", &tmpd) != 1) {
 ast_log(LOG_ERROR, "Argument '%s' is not a floating point number for format '%s'\n", arg.var[argcount - 1], formatbuf);
 goto sprintf_fail;
 }
 } else {
 ast_log(LOG_ERROR, "SPRINTF() has more format specifiers than arguments!\n");
 goto sprintf_fail;
 }

 /* Format the argument */
 snprintf(bufptr, buf + len - bufptr, formatbuf, tmpd);

 /* Update the position of the next parameter to print */
 bufptr = strchr(buf, '\0');
 } else if (arg.format[i] == 's') {
 /* String */

 /* Isolate this format alone */
 ast_copy_string(formatbuf, formatstart, sizeof(formatbuf));
 formatbuf[&arg.format[i] - formatstart + 1] = '\0';

 /* Format the argument */
 snprintf(bufptr, buf + len - bufptr, formatbuf, arg.var[argcount++]);

 /* Update the position of the next parameter to print */
 bufptr = strchr(buf, '\0');
 } else if (arg.format[i] == '%') {
 /* Literal data to copy */
 *bufptr++ = arg.format[i];
 } else {
 /* Not supported */

 /* Isolate this format alone */
 ast_copy_string(formatbuf, formatstart, sizeof(formatbuf));
 formatbuf[&arg.format[i] - formatstart + 1] = '\0';

 ast_log(LOG_ERROR, "Format type not supported: '%s' with argument '%s'\n", formatbuf, arg.var[argcount++]);
 goto sprintf_fail;
 }
 state = -1;
 break;
 default:
 if (arg.format[i] == '%') {
 state = SPRINTF_FLAG;
 formatstart = &arg.format[i];
 break;
 } else {
 /* Literal data to copy */
 *bufptr++ = arg.format[i];
 }
 }
 }
 *bufptr = '\0';
 return 0;
sprintf_fail:
 return -1;
}

static struct ast_custom_function sprintf_function = {
 .name = "SPRINTF",
 .read = acf_sprintf,
};

static int unload_module(void)
{
 int res = 0;

 res |= ast_custom_function_unregister(&sprintf_function);

 return res;
}

static int load_module(void)
{
 int res = 0;

 res |= ast_custom_function_register(&sprintf_function);

 return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "SPRINTF dialplan function");