1. Review & Lab assignments
Lab guide # 10
C File Processing
Review & Lab assignments

2. Key points Data hierarchy File & Stream
Create, read, write and update:
Sequential access file
Random access file

3. Data hierarchy
Bit, bytes, characters, records, files database

4. File & Stream File: Stream: Read/Write function
A sequence of bytes, ends with end-of-file marker
Structure
File descriptor
File control block
Stream:
Provide communication channel between files and programs
File pointer: to be returned when open a file
stdin, stdout, stderr
Read/Write function
fgets, fputc, fgets, fputs, fscanf, fprintf

5. Create, read, write and update
FILE *cfPtr;
cfPtr = fopen(“clients.dat", “w”);
Opening modes
Character mode: r,w,a,r+,w+,a+,
Binary mode: rb,wb,ab,rb+,wb+,ab+
Functions
Random
Sequential
Read
fread
fscanf
Write
fwrite
fprintf
Pointer position
fseek
rewind
Others
feof, fclose

6. Sequential vs. Random access file
Properties
Random
Sequential
Length of records
Fixed
Dynamic
Access individual records without searching through other records
Yes
No, should be searched through other records
Instant access to records No
Data can be inserted without destroying other data
No, Other data can be destroyed
Data previously stored can be updated or deleted without overwriting
Storage memory
High
Low
Human readable

7. Lab Assignment
Fig. 11.8
Fig 11.12
Fig 11.15

8. 4. Lab Assignmentstion 11
Hardware Store You are the owner of a hardware store and need to keep an inventory.
Tool Record
Record #
Tool name
Quantity
Cost
The tool identification number should be the record number.

9. Program
Initialize the random-access file “hardware.dat” to 100 empty records. (ONLY if it was empty)
Menu
Input a tool data.
List all tools.
Delete a tool record.
Update a tool record.

10. Use this information to start your file.
Record number
Tool name
Quantity
Cost 3
Sander 18
35.99 19
Hammer
128
10.00 26
Jigsaw 16
14.25 36
Mower 10
79.50 56
Saw 8
89.99 76
Screwdriver
236
4.99 81
Sledgehammer 32
19.75 88
Wrench 65
6.48