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 Anthony 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");