Programming for Problem Solving (3110003)

BE | Semester-1   Winter-2019 | 07-01-2020

Q4) (b)

Describe file management. And List the various file management functions.

  • In real life, we want to store data permanently so that later on we can retrieve it and reuse it.
  • A file is a collection of bytes stored on a secondary storage device like hard disk, pen drive, and tape.
  • There are two kinds of files that programmers deal with text files and binary files.
  • Text files are human readable and it is a stream of plain English characters.
  • Binary files are not human readable. It is a stream of processed characters and Ascii symbols.

File Opening Modes

  • We want to open files for some purpose like, read files, create new files, append files, read and write files, etc.
  • When we open any file for processing, at that time we have to give file opening mode.
  • We can do limited operations only based on the mode in which the file is opened.
    e.g. fp = fopen(“demo.txt”, ”r”); //Here file is opened in read only mode.
C has 6 different file opening modes for text files
Mode Description
r open for reading only
w open for writing (If file exists then it is overwritten)
a open for appending (If file does not exist then it creates new file)
r+ open for reading and writing, start at beginning
w+ open for reading and writing (overwrite file)
a+ open for reading and writing, at the end (append if file exists)


Same modes are also supported for binary files by just adding b, e.g. rb, wb, ab, r+b, w+b, a+b.