Due: Monday 11/08 8:00 am

  • Here You will find a csv file of NYC census population values.
    • The header of the file is this: Year,Manhattan,Brooklyn,Queens,Bronx,Staten Island
    • An example line of data is this: 1790,33131,4549,6159,1781,3827
  • Your goal: write a program that will perform the following actions based on a command line argument:
    • -read_csv
      • Read the contents of the file (this is text).

      • Store each piece of data using the following struct:

        struct pop_entry {
  int year;
  int population;
  char boro[15];
};
      • Create & write a new file containing the population data using struct pop_entry. This file should contain byte data.
        • If the file already exists, overwrite the existing one.
    • -read_data
      • Read the contents of the data file into an array of struct pop_entry values. This array should be dynamically allocated based on the file size.
      • Display the data in human-readable format, provide a number for each data entry when displaying.
    • -add_data
      • Ask the user for new data to put into a struct pop_entry value.
      • Append that data to the end of the data file (not the csv).
    • -update_data
      • Start like -read_data.
      • Then prompt the user to enter the corresponding number of an entry to modify.
      • Then prompt the user for new data.
      • Update the entry in the data file (not the csv).

Sample output:

  • read_csv 
    $ ./structrw -read_csv
reading nyc_pop.csv
wrote 2760 bytes to nyc_pop.data
  • -read_data
    • This is only the fist 11 entries, there should be 115 at the start. 
      $ ./structrw -read_data
0: year: 1790	boro: Manhattan	pop: 33131
1: year: 1790	boro: Brooklyn	pop: 4549
2: year: 1790	boro: Queens	pop: 6159
3: year: 1790	boro: Bronx	pop: 1781
4: year: 1790	boro: Staten Island	pop: 3827
5: year: 1800	boro: Manhattan	pop: 60515
6: year: 1800	boro: Brooklyn	pop: 5740
7: year: 1800	boro: Queens	pop: 6642
8: year: 1800	boro: Bronx	pop: 1755
9: year: 1800	boro: Staten Island	pop: 4563
10: year: 1810	boro: Manhattan	pop: 96373
  • -add_data
    • 2020 Bronx 1390450 Was entered manually at the time of the program running. 
      $ ./structrw -add_data
Enter year boro pop: 2020 Bronx 1390450
Appended data to file: year: 2020	boro: Bronx	pop: 1390450
  • -update_data
    • Only showing the last ffeew lines of output, but all the data should be displayed.
    • 108 and 9999 Stuy 4000 where entered manually. 
      $ ./structrw -update_data
107: year: 2000	boro: Queens	pop: 2229379
108: year: 2000	boro: Bronx	pop: 1332650
109: year: 2000	boro: Staten Island	pop: 443728
110: year: 2010	boro: Manhattan	pop: 1585873
111: year: 2010	boro: Brooklyn	pop: 2504700
112: year: 2010	boro: Queens	pop: 2230722
113: year: 2010	boro: Bronx	pop: 1385108
114: year: 2010	boro: Staten Island	pop: 468730
115: year: 2020	boro: Bronx	pop: 1390450
entry to update: 108
Enter year boro pop: 9999 Stuy 4000
File updated.