Esercizi file in c

Storing in a file will preserve your data even if the program terminates. If you have to enter a large number of data, it will take a lot of time to enter them all. However, if you have a file containing all the data, you can easily access the contents of the file using a few commands in C.

You can easily move your data from one computer to another without any changes. Types of Files When dealing with files, there are two types of files you should know about: Text files Binary files 1. Text files Text files are the normal. Binary files Binary files are mostly the.

Instead of storing data in plain text, they store it in the binary form 0's and 1's. File Operations In C, you can perform four major operations on files, either text or binary: Creating a new file Opening an existing file Closing a file Reading from and writing information to a file Working with files When working with files, you need to declare a pointer of type file.

The first function creates a new file named newprogram. The writing mode allows you to create and edit overwrite the contents of the file. Now let's suppose the second binary file oldprogram. The second function opens the existing file for reading in binary mode 'rb'. The reading mode only allows you to read the file, you cannot write into the file. If the file does not exist, fopen returns NULL. If the file exists, its contents are overwritten.

If the file does not exist, it will be created. Data is added to the end of the file. Closing a file is performed using the fclose function. Reading and writing to a text file For reading and writing to a text file, we use the functions fprintf and fscanf. Table of Contents Why files? Previous Tutorial:. Next Tutorial:. Share on:. Did you find this article helpful?

Sorry about that. How can we improve it? Leave this field blank. If it is not, then before proceeding, you must create this directory on your machine. When the above code is compiled and executed, it creates a new file test. Let us read this file in the next section. The fgetc function reads a character from the input file referenced by fp.

The return value is the character read, or in case of any error, it returns EOF. The functions fgets reads up to n-1 characters from the input stream referenced by fp. It copies the read string into the buffer buf , appending a null character to terminate the string. Let's see a little more in detail about what happened here. First, fscanf read just This because after that, it encountered a space, second call is for fgets which reads the remaining line till it encountered end of line.

Finally, the last call fgets reads the second line completely. Both of these functions should be used to read or write blocks of memories - usually arrays or structures. Previous Page.

Next Page. Strutture in C. Strutture complesse in C. Come sommare gli elementi della cornice esterna. Press ESC to close. Lezione precedente: file con vettori in C. Lezione successiva: funzione rewind in C. Show Comments. Share Article:.