Sat Aug 6 00:39:29 2011

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: 211528 $")
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 = strchr(ptrkey, ':');
00093       if (!ptrvalue) {
00094          count--;
00095          continue;
00096       }
00097       *ptrvalue++ = '\0';
00098       sortable_keys[count2].key = ptrkey;
00099       sscanf(ptrvalue, "%30f", &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       if (args.delimiter[0] == '\\') {
00149          if (args.delimiter[1] == 'n')
00150             d = '\n';
00151          else if (args.delimiter[1] == 't')
00152             d = '\t';
00153          else if (args.delimiter[1] == 'r')
00154             d = '\r';
00155          else if (args.delimiter[1])
00156             d = args.delimiter[1];
00157          else
00158             d = '-';
00159       } else if (args.delimiter[0])
00160          d = args.delimiter[0];
00161       else
00162          d = '-';
00163 
00164       /* String form of the delimiter, for use with strsep(3) */
00165       snprintf(ds, sizeof(ds), "%c", d);
00166 
00167       pbx_substitute_variables_helper(chan, tmp, tmp2, MAXRESULT - 1);
00168 
00169       if (tmp2) {
00170          int curfieldnum = 1, firstfield = 1;
00171          while (tmp2 != NULL && args.field != NULL) {
00172             char *nextgroup = strsep(&(args.field), "&");
00173             int num1 = 0, num2 = MAXRESULT;
00174             char trashchar;
00175 
00176             if (sscanf(nextgroup, "%30d-%30d", &num1, &num2) == 2) {
00177                /* range with both start and end */
00178             } else if (sscanf(nextgroup, "-%30d", &num2) == 1) {
00179                /* range with end */
00180                num1 = 0;
00181             } else if ((sscanf(nextgroup, "%30d%1c", &num1, &trashchar) == 2) && (trashchar == '-')) {
00182                /* range with start */
00183                num2 = MAXRESULT;
00184             } else if (sscanf(nextgroup, "%30d", &num1) == 1) {
00185                /* single number */
00186                num2 = num1;
00187             } else {
00188                return ERROR_USAGE;
00189             }
00190 
00191             /* Get to start, if any */
00192             if (num1 > 0) {
00193                while (tmp2 != (char *)NULL + 1 && curfieldnum < num1) {
00194                   tmp2 = strchr(tmp2, d) + 1;
00195                   curfieldnum++;
00196                }
00197             }
00198 
00199             /* Most frequent problem is the expectation of reordering fields */
00200             if ((num1 > 0) && (curfieldnum > num1))
00201                ast_log(LOG_WARNING, "We're already past the field you wanted?\n");
00202 
00203             /* Re-null tmp2 if we added 1 to NULL */
00204             if (tmp2 == (char *)NULL + 1)
00205                tmp2 = NULL;
00206 
00207             /* Output fields until we either run out of fields or num2 is reached */
00208             while (tmp2 != NULL && curfieldnum <= num2) {
00209                char *tmp3 = strsep(&tmp2, ds);
00210                int curlen = strlen(buffer);
00211 
00212                if (firstfield) {
00213                   snprintf(buffer, buflen, "%s", tmp3);
00214                   firstfield = 0;
00215                } else {
00216                   snprintf(buffer + curlen, buflen - curlen, "%c%s", d, tmp3);
00217                }
00218                curfieldnum++;
00219             }
00220          }
00221       }
00222    }
00223    return 0;
00224 }
00225 
00226 static int acf_sort_exec(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len)
00227 {
00228    struct ast_module_user *u;
00229    int ret = -1;
00230 
00231    u = ast_module_user_add(chan);
00232 
00233    switch (sort_internal(chan, data, buf, len)) {
00234    case ERROR_NOARG:
00235       ast_log(LOG_ERROR, "SORT() requires an argument\n");
00236       break;
00237    case ERROR_NOMEM:
00238       ast_log(LOG_ERROR, "Out of memory\n");
00239       break;
00240    case 0:
00241       ret = 0;
00242       break;
00243    default:
00244       ast_log(LOG_ERROR, "Unknown internal error\n");
00245    }
00246 
00247    ast_module_user_remove(u);
00248 
00249    return ret;
00250 }
00251 
00252 static int acf_cut_exec(struct ast_channel *chan, char *cmd, char *data, char *buf, size_t len)
00253 {
00254    int ret = -1;
00255    struct ast_module_user *u = NULL;
00256 
00257    if (chan) {
00258       u = ast_module_user_add(chan);
00259    }
00260 
00261    switch (cut_internal(chan, data, buf, len)) {
00262    case ERROR_NOARG:
00263       ast_log(LOG_ERROR, "Syntax: CUT(<varname>,<char-delim>,<range-spec>) - missing argument!\n");
00264       break;
00265    case ERROR_NOMEM:
00266       ast_log(LOG_ERROR, "Out of memory\n");
00267       break;
00268    case ERROR_USAGE:
00269       ast_log(LOG_ERROR, "Usage: CUT(<varname>,<char-delim>,<range-spec>)\n");
00270       break;
00271    case 0:
00272       ret = 0;
00273       break;
00274    default:
00275       ast_log(LOG_ERROR, "Unknown internal error\n");
00276    }
00277 
00278    if (chan) {
00279       ast_module_user_remove(u);
00280    }
00281 
00282    return ret;
00283 }
00284 
00285 struct ast_custom_function acf_sort = {
00286    .name = "SORT",
00287    .synopsis = "Sorts a list of key/vals into a list of keys, based upon the vals",
00288    .syntax = "SORT(key1:val1[...][,keyN:valN])",
00289    .desc =
00290 "Takes a comma-separated list of keys and values, each separated by a colon, and returns a\n"
00291 "comma-separated list of the keys, sorted by their values.  Values will be evaluated as\n"
00292 "floating-point numbers.\n",
00293    .read = acf_sort_exec,
00294 };
00295 
00296 struct ast_custom_function acf_cut = {
00297    .name = "CUT",
00298    .synopsis = "Slices and dices strings, based upon a named delimiter.",
00299    .syntax = "CUT(<varname>,<char-delim>,<range-spec>)",
00300    .desc =
00301 "  varname    - variable you want cut\n"
00302 "  char-delim - defaults to '-'\n"
00303 "  range-spec - number of the field you want (1-based offset)\n"
00304 "             may also be specified as a range (with -)\n"
00305 "             or group of ranges and fields (with &)\n",
00306    .read = acf_cut_exec,
00307 };
00308 
00309 static int unload_module(void)
00310 {
00311    int res = 0;
00312 
00313    res |= ast_custom_function_unregister(&acf_cut);
00314    res |= ast_custom_function_unregister(&acf_sort);
00315 
00316    ast_module_user_hangup_all();
00317 
00318    return res;
00319 }
00320 
00321 static int load_module(void)
00322 {
00323    int res = 0;
00324 
00325    res |= ast_custom_function_register(&acf_cut);
00326    res |= ast_custom_function_register(&acf_sort);
00327 
00328    return res;
00329 }
00330 
00331 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Cut out information from a string");

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