C segmentation fault, can anybody help me identify why? -

i using following code split char array in c:

    char line[100]; int number_of_gga_parsed = 0; int gga_blocks_allocated;     gga_sentence *ggas_parsed;     gsa_sentence gsa;     gsv_sentence gsv;       ggas_parsed = malloc(10*sizeof(gga_sentence));     gga_blocks_allocated = 10;      if(ggas_parsed == null){          printf("error allocating memory, system exiting.\n");         exit(exit_failure);     }      while(fscanf(stream, "%s", line)!= eof){      strcpy((ggas_parsed + number_of_gga_parsed)->untouched_sentence, line);      initiate_gga_values((ggas_parsed + number_of_gga_parsed),(ggas_parsed + number_of_gga_parsed)->untouched_sentence); 

}

initiate_gga_values function:

void initiate_gga_values(gga_sentence* gga_ptr, const char* sentence){      char *temp_sentence;     char *token;     int token_no = 0;      /*copy gga_sentence temp_sentence char array*/     strcpy(temp_sentence, sentence);       token = strsep (temp_sentence,",");      while (token != null) {         switch(token_no){         case 0:             gga_ptr->sentence_id = token;             break;         case 1:             /*atoi converts string int, c string anyways char* */             gga_ptr->time_stamp = atoi(token);             break;         case 2:             /*strtod coverts string double, c string anyways char* */             gga_ptr->latitude = strtod(token, null);             break;         case 3:             gga_ptr->north_south_id = (char)token;             break;         case 4:             gga_ptr->longitude = strtod(token, null);             break;         case 5:             gga_ptr->east_west_id = (char)token;             break;         case 6:             gga_ptr->quality = atoi(token);             break;         case 7:             gga_ptr->no_of_satellites = atoi(token);             break;         case 8:             gga_ptr->horizontal_dillution = strtod(token, null);             break;         case 9:             gga_ptr->altitude = strtod(token, null);             break;         case 10:             gga_ptr->altitude_units = (char)token;             break;         case 11:             gga_ptr->geodial_seperation = strtod(token, null);             break;         case 12:             gga_ptr->geodial_seperation_units = (char)token;             break;         case 13:             gga_ptr->age_of_data_in_seconds = strtod(token, null);             break;         case 14:             gga_ptr->checksum = token;             break;         }         token_no++;         token = strsep (temp_sentence, ",");           } } 

the char array consists of information:

$gpgga,151019.000,5225.9627,n,00401.1624,w,1,09,1.0,38.9,m,51.1,m,,0000*72 

but when code in run on above, segmentation fault:

segmentation fault (core dumped) 

gga struct:

typedef struct gga_sentence{      char untouched_sentence[100];     gsa_sentence gsa;     char *sentence_id;     int time_stamp;     double latitude;     char north_south_id;     double longitude;     char east_west_id;     int quality;     int no_of_satellites;     double horizontal_dillution;     double altitude;     char altitude_units;     double geodial_seperation;     char geodial_seperation_units;     double age_of_data_in_seconds;     char *checksum;  }gga_sentence; 

the segmentation fault happens before function initiate_gga_values function completes, or starts really. means assume there problem mallocing of gga_sentences cannot see where!

this first time using strsep, no doubt doing wrong.

gdb error message:

program received signal sigsegv, segmentation fault. 0x00007ffff7de4103 in _dl_lookup_symbol_x (undef_name=0x4004d8 "strlen", undef_map=0x7ffff7ffe268,      ref=ref@entry=0x7fffffffdbb8, symbol_scope=0x302e312c362e312c, version=0x7ffff7ff9a08,      type_class=type_class@entry=1, flags=1, skip_map=skip_map@entry=0x0) @ dl-lookup.c:733 733 dl-lookup.c: no such file or directory. 

cheers, chris.

char *temp_sentence; char *token; int token_no = 0;  /*copy gga_sentence temp_sentence char array*/ strcpy(temp_sentence, sentence); 

you aren't allocating memory temp_sentence hold copied string