Text File Modes in C

During programming text file can be opened for different purposes i.e. reading, writing or both. This is specified by using file modes. Different text file modes in C programming are tabulated below:

Modes Purpose
r Open text file for reading only. The file must already exist.
w Open text file for writing only. If the file specified already exists, its contents will be destroyed. If it does not exist it will be created.
a Open text file for appending (i.e. adding data to the end of existing file). If it does not exist it will be created.
r+ Open text file for both reading and writing. The file must already exist.
w+ Open text file for both reading and writing. If the file exists, its content will be overwritten. If it does not exist it will be created.
a+ Open text file for both reading and appending. If a file does not exist it will be created.