The two files are. The first part of the loop:. At this point, both the index file struct and the data file string can be written to their respective files. Although these are binary files, they are written sequentially.
In theory, you could write records to a position beyond the current end of file, but it's not a good technique to use and probably not at all portable. The final part is to close both files. This ensures that the last part of the file is written to disk. During file writes, many of the writes don't go directly to disk but are held in fixed-sized buffers.
After a write fills the buffer, the entire contents of the buffer are written to disk. A file flush function forces flushing and you can also specify file flushing strategies, but those are intended for text files. To test that any specified record from the data file can be retrieved, you need to know two things: where it starts in the data file and how big it is.
This is what the index file does. There are two other constants defined for this. Having obtained the size and position of the data, it just remains to fetch it. Here, use fsetpos because of the type of index.
An alternative way is to use ftell instead of fgetpos and fsek instead of fgetpos. Don't forget it or you'll get a crash. As before, fclose is called on both files. Although you won't lose any data if you forget fclose unlike with writes , you will have a memory leak.
Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. If you elaborate on that, that would really help me adapt my code more accurately to your needs. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?
Collectives on Stack Overflow. Learn more. Asked 7 years, 11 months ago. Active 7 years, 11 months ago. Viewed 1k times. Entire question : Question 3 You are the owner of a hardware store and need to keep an inventory that can tell you what different tools you have, how many of each you have on hand and the cost of each one. Tool Name Quantity Cost 4 electric hammer 3 Thank you for your attention.
Casper Casper 3, 9 9 gold badges 40 40 silver badges 66 66 bronze badges. Can you explain your problem please? It helps a little. FYI You haven't created objects; you made 1 object and wrote to it times. Unless the tool name is a plain array with a fixed size, you can't write class instances like that.
When a match occurs i. Assume purchases are indicated by positive amounts on the transaction file and payments are indicated by negative amounts. When there is a master record for a particular account but no corresponding transaction record, merely write the master record to newmast. After writing the program of Exercise Use the following sample account data:.
Run the program of Exercise Check that the accounts have been updated correctly. It is possible actually common to have several transaction records with the same record key. This occurs because a particular customer might make several purchases and cash payments during a business period. Rewrite your accounts-receivable file-matching program of Exercise Modify the test data of Exercise Write a series of statements that accomplish each of the following.
Assume that we have defined class Person that contains private data members Also assume that any random-access files have been opened properly. Initialize the file nameage. Input 10 last names, first names and ages, and write them to the file. Update a record that already contains information.
If the record does not contain information, inform the user "No info". Delete a record that contains information by reinitializing that particular record. You are the owner of a hardware store and need to keep an inventory that can tell you what different tools you have, how many of each you have on hand and the cost of each one. Write a program that initializes the randomaccess file hardware.
The tool identification number should be the record number. Use the following information to start your file:. Telephone Number Word Generator Standard telephone keypads contain the digits 0 through 9. The numbers 2 through 9 each have three letters associated with them, as is indicated by the following table:Many people find it difficult to memorize phone numbers, so they use the correspondence between digits and letters to develop seven-letter words that correspond to their phone numbers.
If a business can advertise a simple word for its customers to dial, then no doubt the business will receive a few more calls. You are the owner of a hardware store and need to keep an inventory that can tell you what different tools you have, how many of each you have on hand, and the cost of each one.
Write a program that initializes the random access file "hardware. The tool identification number should be the record number. That the tool name field length does not exceed the maximum length of the tool name field in the record struct used to save this information in the direct access field. Load the data of the nodes of the linked list from an existing direct access data file in the constructor.
Create a direct access data file where one did not exist before. This code might or might not be well placed in a function where the first record of a new data base is created. Insert a new node that is read from the file. The user should now be able to specify a particular record by using the number of that record in the file.
One user friendly way to do this is to print a numbered list of all the records in the file and let the user press the number of the record to be added by pressing the number that corresponds to the desired record.
Add a new record to the direct access file. Modify the function insertNewNodeInOrder such that it inserts the new node in the linked list already done in previous version AND inserts it in the direct access file.
This may be tricky. Delete directly a record from the direct access file. Modify the deleteNode so that the same data is deleted from both the linked list and the direct access file. Do you have to physically delete the record from the file, or can you merely mark it as deleted? Marking it would save the time used to rewrite all of the records that come after the deleted record.
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