func_sprintf.c

Go to the documentation of this file.

/*
 * 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");