Wed Aug 15 01:24:21 2007

Asterisk developer's documentation


func_cut.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (c) 2003-2006 Tilghman Lesher.  All rights reserved.
00005  *
00006  * Tilghman Lesher <app_cut__v003@the-tilghman.com>
00007  *
00008  * This code is released by the author with no restrictions on usage.
00009  *
00010  * See http://www.asterisk.org for more information about
00011  * the Asterisk project. Please do not directly contact
00012  * any of the maintainers of this project for assistance;
00013  * the project provides a web site, mailing lists and IRC
00014  * channels for your use.
00015  *
00016  */
00017 
00018 /*! \file
00019  * 
00020  * \brief CUT function
00021  *
00022  * \author Tilghman Lesher <app_cut__v003@the-tilghman.com>
00023  *
00024  * \ingroup functions
00025  */
00026 
00027 #include "asterisk.h"
00028 
00029 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 40722 $")
00030 
00031 #include <stdio.h>
00032 #include <stdlib.h>
00033 #include <unistd.h>
00034 #include <string.h>
00035 
00036 #include "asterisk/file.h"
00037 #include "asterisk/logger.h"
00038 #include "asterisk/options.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/pbx.h"
00041 #include "asterisk/module.h"
00042 #include "asterisk/app.h"
00043 
00044 /* Maximum length of any variable */
00045 #define MAXRESULT 1024
00046 
00047 struct sortable_keys {
00048    char *key;
00049    float value;
00050 };
00051 
00052 static int sort_subroutine(const void *arg1, const void *arg2)
00053 {
00054    const struct sortable_keys *one=arg1, *two=arg2;
00055    if (one->value < two->value)
00056       return -1;
00057    else if (one->value == two->value)
00058       return 0;
00059    else
00060       return 1;
00061 }
00062 
00063 #define ERROR_NOARG  (-1)
00064 #define ERROR_NOMEM  (-2)
00065 #define ERROR_USAGE  (-3)
00066 
00067 static int sort_internal(struct ast_channel *chan, char *data, char *buffer, size_t buflen)
00068 {
00069    char *strings, *ptrkey, *ptrvalue;
00070    int count=1, count2, element_count=0;
00071    struct sortable_keys *sortable_keys;
00072 
00073    memset(buffer, 0, buflen);
00074 
00075    if (!data)
00076       return ERROR_NOARG;
00077 
00078    strings = ast_strdupa(data);
00079 
00080    for (ptrkey = strings; *ptrkey; ptrkey++) {
00081       if (*ptrkey == '|')
00082          count++;
00083    }
00084 
00085    sortable_keys = alloca(count * sizeof(struct sortable_keys));
00086 
00087    memset(sortable_keys, 0, count * sizeof(struct sortable_keys));
00088 
00089    /* Parse each into a struct */
00090    count2 = 0;
00091    while ((ptrkey = strsep(&strings, "|"))) {
00092       ptrvalue = index(ptrkey, ':');
00093       if (!ptrvalue) {
00094          count--;
00095          continue;
00096       }
00097       *ptrvalue++ = '\0';
00098       sortable_keys[count2].key = ptrkey;
00099       sscanf(ptrvalue, "%f", &sortable_keys[count2].value);
00100       count2++;
00101    }
00102 
00103    /* Sort the structs */
00104    qsort(sortable_keys, count, sizeof(struct sortable_keys), sort_subroutine);
00105 
00106    for (count2 = 0; count2 < count; count2++) {
00107       int blen = strlen(buffer);
00108       if (element_count++) {
00109          strncat(buffer + blen, ",", buflen - blen - 1);
00110          blen++;
00111       }
00112       strncat(buffer + blen, sortable_keys[count2].key, buflen - blen - 1);
00113    }
00114 
00115    return 0;
00116 }
00117 
00118 static int cut_internal(struct ast_channel *chan, char *data, char *buffer, size_t buflen)
00119 {
00120    char *parse;
00121    AST_DECLARE_APP_ARGS(args,
00122       AST_APP_ARG(varname);
00123       AST_APP_ARG(delimiter);
00124       AST_APP_ARG(field);
00125    );
00126 
00127    memset(buffer, 0, buflen); 
00128    
00129    parse = ast_strdupa(data);
00130 
00131    AST_STANDARD_APP_ARGS(args, parse);
00132 
00133    /* Check and parse arguments */
00134    if(args.argc < 3){
00135       return ERROR_NOARG;
00136    } else {
00137       char d, ds[2];
00138       char *tmp = alloca(strlen(args.varname) + 4);
00139       char varvalue[MAXRESULT], *tmp2=varvalue;
00140 
00141       if (tmp) {
00142          snprintf(tmp, strlen(args.varname) + 4, "${%s}", args.varname);
00143          memset(varvalue, 0, sizeof(varvalue));
00144       } else {
00145          return ERROR_NOMEM;
00146       }
00147 
00148       d = args.delimiter[0] ? args.delimiter[0] : '-';
00149 
00150       /* String form of the delimiter, for use with strsep(3) */
00151       snprintf(ds, sizeof(ds), "%c", d);
00152 
00153       pbx_substitute_variables_helper(chan, tmp, tmp2, MAXRESULT - 1);
00154 
00155       if (tmp2) {
00156          int curfieldnum = 1;
00157          while (tmp2 != NULL && args.field != NULL) {
00158             char *nextgroup = strsep(&(args.field), "&");
00159             int num1 = 0, num2 = MAXRESULT;
00160             char trashchar;
00161 
00162             if (sscanf(nextgroup, "%d-%d", &num1, &num2) == 2) {
00163                /* range with both start and end */
00164             } else if (sscanf(nextgroup, "-%d", &num2) == 1) {
00165                /* range with end */
00166                num1 = 0;
00167             } else if ((sscanf(nextgroup, "%d%c", &num1, &trashchar) == 2) && (trashchar == '-')) {
00168                /* range with start */
00169                num2 = MAXRESULT;
00170             } else if (sscanf(nextgroup, "%d", &num1) == 1) {
00171                /* single number */
00172                num2 = num1;
00173             } else {
00174                return ERROR_USAGE;
00175             }
00176 
00177             /* Get to start, if any */
00178             if (num1 > 0) {
00179                while (tmp2 != (char *)NULL + 1 && curfieldnum < num1) {
00180                   tmp2 = index(tmp2, d) + 1;
00181                   curfieldnum++;
00182                }
00183             }
00184 
00185             /* Most frequent problem is the expectation of reordering fields */
00186             if ((num1 > 0) && (curfieldnum > num1))
00187                ast_log(LOG_WARNING, "We're already past the field you wanted?\n");
00188 
00189             /* Re-null tmp2 if we added 1 to NULL */
00190             if (tmp2 == (char *)NULL + 1)
00191                tmp2 = NULL;
00192 
00193             /* Output fields until we either run out of fields or num2 is reached */
00194             while (tmp2 != NULL && curfieldnum <= num2) {
00195                char *tmp3 = strsep(&tmp2, ds);
00196                int curlen = strlen(buffer);
00197 
00198                if (curlen)
00199                   snprintf(buffer + curlen, buflen - curlen, "%c%s", d, tmp3);
00200                else
00201                   snprintf(buffer, buflen, "%s", tmp3);
00202 
00203                curfieldnum++;
00204             }
00205          }
00206       }
00207    }
00208    return 0;
00209 }
00210 
00211 static int acf_sort_exec(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len)
00212 {
00213    struct ast_module_user *u;
00214    int ret = -1;
00215 
00216    u = ast_module_user_add(chan);
00217 
00218    switch (sort_internal(chan, data, buf, len)) {
00219    case ERROR_NOARG:
00220       ast_log(LOG_ERROR, "SORT() requires an argument\n");
00221       break;
00222    case ERROR_NOMEM:
00223       ast_log(LOG_ERROR, "Out of memory\n");
00224       break;
00225    case 0:
00226       ret = 0;
00227       break;
00228    default:
00229       ast_log(LOG_ERROR, "Unknown internal error\n");
00230    }
00231 
00232    ast_module_user_remove(u);
00233 
00234    return ret;
00235 }
00236 
00237 static int acf_cut_exec(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len)
00238 {
00239    int ret = -1;
00240    struct ast_module_user *u;
00241 
00242    u = ast_module_user_add(chan);
00243 
00244    switch (cut_internal(chan, data, buf, len)) {
00245    case ERROR_NOARG:
00246       ast_log(LOG_ERROR, "Syntax: CUT(<varname>,<char-delim>,<range-spec>) - missing argument!\n");
00247       break;
00248    case ERROR_NOMEM:
00249       ast_log(LOG_ERROR, "Out of memory\n");
00250       break;
00251    case ERROR_USAGE:
00252       ast_log(LOG_ERROR, "Usage: CUT(<varname>,<char-delim>,<range-spec>)\n");
00253       break;
00254    case 0:
00255       ret = 0;
00256       break;
00257    default:
00258       ast_log(LOG_ERROR, "Unknown internal error\n");
00259    }
00260 
00261    ast_module_user_remove(u);
00262 
00263    return ret;
00264 }
00265 
00266 struct ast_custom_function acf_sort = {
00267    .name = "SORT",
00268    .synopsis = "Sorts a list of key/vals into a list of keys, based upon the vals",
00269    .syntax = "SORT(key1:val1[...][,keyN:valN])",
00270    .desc =
00271 "Takes a comma-separated list of keys and values, each separated by a colon, and returns a\n"
00272 "comma-separated list of the keys, sorted by their values.  Values will be evaluated as\n"
00273 "floating-point numbers.\n",
00274    .read = acf_sort_exec,
00275 };
00276 
00277 struct ast_custom_function acf_cut = {
00278    .name = "CUT",
00279    .synopsis = "Slices and dices strings, based upon a named delimiter.",
00280    .syntax = "CUT(<varname>,<char-delim>,<range-spec>)",
00281    .desc =
00282 "  varname    - variable you want cut\n"
00283 "  char-delim - defaults to '-'\n"
00284 "  range-spec - number of the field you want (1-based offset)\n"
00285 "             may also be specified as a range (with -)\n"
00286 "             or group of ranges and fields (with &)\n",
00287    .read = acf_cut_exec,
00288 };
00289 
00290 static int unload_module(void)
00291 {
00292    int res = 0;
00293 
00294    res |= ast_custom_function_unregister(&acf_cut);
00295    res |= ast_custom_function_unregister(&acf_sort);
00296 
00297    ast_module_user_hangup_all();
00298 
00299    return res;
00300 }
00301 
00302 static int load_module(void)
00303 {
00304    int res = 0;
00305 
00306    res |= ast_custom_function_register(&acf_cut);
00307    res |= ast_custom_function_register(&acf_sort);
00308 
00309    return res;
00310 }
00311 
00312 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Cut out information from a string");

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