How to change a specific entity of a specific record stored in a file in c++ -

hi friends want modify specific entity of specific record stored in file. have stored record in file as

roll no: 35

name: adnan irshad

status: not admitted

roll no: 40

name: adeel ahmed

status: not admitted

roll no: 30

name: arish

adnan: not admitted

roll no: 35

name: shan

status: not admitted

here want search record via roll no , change status of record admitted input 30 roll no search record , program search record , change status admitted. have done code change 1 record when record nothing happen. code here

    char stat[13];      cout<<"enter registration no";      cin>>reg_no;      fstream out("intermediate.txt",ios::in|ios::out|ios::ate|ios::app);      out.seekg(0,ios::beg);      out.read((char*)&std,sizeof(std));      while(!out.eof())       {            record_no++;          if(strcmp(std.get_reg_no(),reg_no)==0)          {              found=1;              break;          }       }      location=(record_no-1)*sizeof(std);      out.seekp(location,ios::beg);      char new_status[]="addmitted"; // initialized replace status      strcpy(std.status,new_status);      out.write((char*)&std,sizeof(std));      out.close(); 

to modify text file:

1. load file memory (such std::vector<my_data_struct>)
2. modify data in memory
3. write memory file

you making significant mistakes costing you:

• don't use goto; there better way (subfunctions)
• don't loop on eof
• use std::string instead of char*
• modularize, modularize, modularize

that last point needs additional help: 1 thing @ time. main code should like:

get user input (filename, item modify, etc)  std::vector<items> items = load_file( filename ); auto item = std::find( items.begin(), items.end(), my_search_criterion_predicate ); if (item != items.end()) {   modify item; } write_file( items );  user output 

all of these require little learning on part, worth effort.