C Programming Language

Hardware Store Database hashing to disk (next pages). Review the following two examples. You are expected to write similar code.

Reuse as much code as possible.

Example 5-2: (e_5_2_hash.c)

- Create an empty hash table of "struct record"

- Prompt the user to enter data, hash the key, and insert the data at the index

given by the hash function, and repeat, to populate the hash table

- Write the hash table to a binary file: we are "cheating" here because we

write the hashed table to the file and then pretend that it does not exist so

we could demonstrate how to use hash search in a binary file

- Collisions are not solved in this example

Example 5-7: (e_5_7_hash.c)

- A record in the binary file is a "bucket" of 4 structs

- This provides room for synonyms

- When a bucket becomes full, the records are added at the end of the file in

File names

Create empty binary file 10

Insert from the keyboard 15

Insert from text file 10

Find and display 15

Delete 10

Error checking

(advanced string manipulation) Self-Assessment Report: 5Points

5

10

Write a short report (26B_H3Report.docx), briefly explaining your code and containing an assessment of your implementation based on the above grading criteria.

CIS 26B Advanced C Programming Assignments

Hardware Store Database hashing to disk

Write a program that allows additions to, deletions from, or displays of database records in a hardware store database. The records in the database will consists of the following fields: id string length is exactly 4 characters (digits only) // key field

name string length up to 20 characters (letters, spaces, and ( )). This string represents the name of a product that could be found at a hardware store.

qty an integer. The number represents the quantity available for that product. Assume this program deals with a large number of records, therefore hashing to memory

is not an option. Assume that an empty hashed tables capacity is 10 three-struct buckets.

Use hardware.dat as a default file name. If the user passes a file name to the program as an argv parameter, use that name.

Open the file for writing to/reading from (in binary). If the file is not found, create an empty hash table of 10 three-struct buckets and use it to create an empty binary file to be used for hashing and searching. The empty hashed file will hold 30 three-struct buckets and no overflow area (i.e. write the empty hash table to the file 3 times).

Report and reject record additions that overflow the 3-record bucket for each hash location.

The hash key is the id and you should sum the cube of the ASCII values of the characters making up the id before dividing by 30 to find the bucket to put the record.

Put names in the file in upper case. For instance, Bolt will be stored as BOLT.

Present the user with a menu to:

S - Search (by the unique key, id)

D - Delete (by the unique key, id)

I - Insert one record from the keyboard.

B - Allow more data to be added from a specified input text file to your data base.

For testing use the following two text files: jan_hw.txt and new_hw.txt

E-Exit

Do complete error checking for keyboard added records: the user should enter id, name, and quantity on one line with any amount of whitespace around the three tokens.

Examples of valid input:

 9162,Flash Light:25 

 9162 , FLaSH LIghT : 25 

CIS 26B Advanced C Programming Assignments

It is a major task to parse, case, and space the requested input so that it agrees with your format in the hashed file. A valid name should consist of letters, spaces, and (). You must follow all the rules for good token parsing.

Examples of invalid input:

9162 Flash Light:25 // missing , after ID 9162,Flash Light 25 // missing : after name 91A2 Flash Light:25 // invalid ID digits only 91-2 Flash Light:25 // invalid ID digits only 5392,BOLT [REGULAR]:1311 // invalid name [ ] not allowed 5392,BOLT (REGU1AR):1311 // invalid name digits not allowed 9162,Flash Light:2A // invalid quantity

9162,Flash Light: // incomplete input line This challenging project involves more than 400 lines of code and uses everything from

this chapter. It uses strtok() and strtod() and possibly other string.h functions.

Run the program at least twice (one session is for error testing). Duplicate id not allowed.

When reading data from a file, we assume data have been validated, therefore we may consider that the file is valid and correctly formatted.

jan_hw.txt

6745,MOLLY BOLT:57 5675,SCREW DRIVER:199 1235,WIDGET:28 2341,WING NUT:89 8624,SLEDGE HAMMER:27 9162,FLASH LIGHT:25 7146,CEMENT BAGS:113 2358,VISE:44 1622,HAMMER:15 1832,THERMOSTAT:78 3271,NAIL:2345 4717,BRACE:234 

new_hw.txt

9524,CLAMP:523 1524,SANDER:99 5219,SAW:211 6275,SAW BLADE:675 5392,BOLT (REGULAR):1311 5192,SCREW DRIVER:789