apps/app_cut.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Cut application
   5  *
   6  * Copyright (c) 2003 Tilghman Lesher.  All rights reserved.
   7  *
   8  * Tilghman Lesher <app_cut__v002@the-tilghman.com>
   9  *
  10  * $Id$
  11  *
  12  * This code is released by the author with no restrictions on usage.
  13  *
  14  */
  15
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #include <string.h>
  20 #include <asterisk/file.h>
  21 #include <asterisk/logger.h>
  22 #include <asterisk/options.h>
  23 #include <asterisk/channel.h>
  24 #include <asterisk/pbx.h>
  25 #include <asterisk/module.h>
  26
  27 /* Maximum length of any variable */
  28 #define MAXRESULT       1024
  29
  30 static char *tdesc = "Cuts up variables";
  31
  32 static char *app_cut = "Cut";
  33
  34 static char *cut_synopsis = "Cut(newvar=varname|delimiter|fieldspec)";
  35
  36 static char *cut_descrip =
  37 "Cut(varname=varname,delimiter,field)\n"
  38 "  newvar    - result string is set to this variable\n"
  39 "  varname   - variable you want cut\n"
  40 "  delimiter - defaults to -\n"
  41 "  fieldspec - number of the field you want (1-based offset)\n"
  42 "            may also be specified as a range (with -)\n"
  43 "            or group of ranges and fields (with &)\n"
  44 "  Returns 0 or -1 on hangup or error.\n";
  45
  46 STANDARD_LOCAL_USER;
  47
  48 LOCAL_USER_DECL;
  49
  50 static int cut_exec(struct ast_channel *chan, void *data)
  51 {
  52         int res=0;
  53         struct localuser *u;
  54         char *s, *newvar=NULL, *varname=NULL, *delimiter=NULL, *field=NULL;
  55         int args_okay = 0;
  56
  57         LOCAL_USER_ADD(u);
  58
  59         /* Check and parse arguments */
  60         if (data) {
  61                 s = ast_strdupa((char *)data);
  62                 if (s) {
  63                         newvar = strsep(&s, "=");
  64                         if (newvar && (newvar[0] != '\0')) {
  65                                 varname = strsep(&s, "|");
  66                                 if (varname && (varname[0] != '\0')) {
  67                                         delimiter = strsep(&s, "|");
  68                                         if (delimiter) {
  69                                                 field = strsep(&s, "|");
  70                                                 if (field) {
  71                                                         args_okay = 1;
  72                                                 }
  73                                         }
  74                                 }
  75                         }
  76                 } else {
  77                         ast_log(LOG_ERROR, "Out of memory\n");
  78                         res = -1;
  79                 }
  80         }
  81
  82         if (args_okay) {
  83                 char d, ds[2];
  84                 char *tmp = alloca(strlen(varname) + 4);
  85                 char *tmp2 = alloca(MAXRESULT);
  86                 char retstring[MAXRESULT];
  87
  88                 memset(retstring, 0, MAXRESULT);
  89
  90                 if (tmp && tmp2) {
  91                         snprintf(tmp, strlen(varname) + 4, "${%s}", varname);
  92                         memset(tmp2, 0, sizeof(tmp2));
  93                 } else {
  94                         ast_log(LOG_ERROR, "Out of memory");
  95                         return -1;
  96                 }
  97
  98                 if (delimiter[0])
  99                         d = delimiter[0];
 100                 else
 101                         d = '-';
 102
 103                 /* String form of the delimiter, for use with strsep(3) */
 104                 sprintf(ds,"%c",d);
 105
 106                 pbx_substitute_variables_helper(chan, tmp, tmp2, MAXRESULT - 1);
 107
 108                 if (tmp2) {
 109                         int curfieldnum = 1;
 110                         while ((tmp2 != NULL) && (field != NULL)) {
 111                                 char *nextgroup = strsep(&field, "&");
 112                                 int num1 = 0, num2 = MAXRESULT;
 113                                 char trashchar;
 114
 115                                 if (sscanf(nextgroup, "%d-%d", &num1, &num2) == 2) {
 116                                         /* range with both start and end */
 117                                 } else if (sscanf(nextgroup, "-%d", &num2) == 1) {
 118                                         /* range with end */
 119                                         num1 = 0;
 120                                 } else if ((sscanf(nextgroup, "%d%c", &num1, &trashchar) == 2) && (trashchar == '-')) {
 121                                         /* range with start */
 122                                         num2 = MAXRESULT;
 123                                 } else if (sscanf(nextgroup, "%d", &num1) == 1) {
 124                                         /* single number */
 125                                         num2 = num1;
 126                                 } else {
 127                                         ast_log(LOG_ERROR, "Cut(): Illegal range '%s'\n", nextgroup);
 128                                         ast_log(LOG_ERROR, "Usage: %s\n", cut_synopsis);
 129                                         return -1;
 130                                 }
 131
 132                                 /* Get to start, if any */
 133                                 if (num1 > 0) {
 134                                         while ((tmp2 != (char *)NULL + 1) && (curfieldnum < num1)) {
 135                                                 tmp2 = index(tmp2, d) + 1;
 136                                                 curfieldnum++;
 137                                         }
 138                                 }
 139
 140                                 /* Most frequent problem is the expectation of reordering fields */
 141                                 if ((num1 > 0) && (curfieldnum > num1)) {
 142                                         ast_log(LOG_WARNING, "Cut(): we're already past the field you wanted?\n");
 143                                 }
 144
 145                                 /* Re-null tmp2 if we added 1 to NULL */
 146                                 if (tmp2 == (char *)NULL + 1)
 147                                         tmp2 = NULL;
 148
 149                                 /* Output fields until we either run out of fields or num2 is reached */
 150                                 while ((tmp2 != NULL) && (curfieldnum <= num2)) {
 151                                         char *tmp3 = strsep(&tmp2, ds);
 152                                         int curlen = strlen(retstring);
 153
 154                                         if (strlen(retstring)) {
 155                                                 snprintf(retstring + curlen, MAXRESULT - curlen, "%c%s", d, tmp3);
 156                                         } else {
 157                                                 snprintf(retstring, MAXRESULT, "%s", tmp3);
 158                                         }
 159
 160                                         curfieldnum++;
 161                                 }
 162                         }
 163                 }
 164
 165                 pbx_builtin_setvar_helper(chan, newvar, retstring);
 166         }
 167
 168         LOCAL_USER_REMOVE(u);
 169         return res;
 170 }
 171
 172 int unload_module(void)
 173 {
 174         STANDARD_HANGUP_LOCALUSERS;
 175         return ast_unregister_application(app_cut);
 176 }
 177
 178 int load_module(void)
 179 {
 180         return ast_register_application(app_cut, cut_exec, cut_synopsis, cut_descrip);
 181 }
 182
 183 char *description(void)
 184 {
 185         return tdesc;
 186 }
 187
 188 int usecount(void)
 189 {
 190         int res;
 191         STANDARD_USECOUNT(res);
 192         return res;
 193 }
 194
 195 char *key()
 196 {
 197         return ASTERISK_GPL_KEY;
 198 }