Intermediate C Programming, 2nd Edition

Chapter 9Reading and Writing Files

DOI: 10.1201/9781003257981-9

We have already taken advantage of redirection to use files as inputs and outputs. This chapter explains how to use C functions to read from or write to files.

9.1 Read from Files

A program has many ways to obtain input data, for example:

1. Use scanf to get data from a user through the keyboard.

2. Use scanf and redirection to get data from a file.

3. Use argc and argv to get data from the command line.

4. Use argv[1] as the name of an input file and read the data stored on a disk.

The first three methods have been explained in earlier chapters. This chapter explains the fourth method. After getting the file's name from argv[1], we need to open the file for reading. This is accomplished ...