Irve: Uus lehekülg: 'This practice is about writing data in binary format. == Task == There are two tasks; the first one is simple fread() fwrite() to get the general idea accross, the second need...'

2018-11-02T09:29:17Z

Uus lehekülg: 'This practice is about writing data in binary format. == Task == There are two tasks; the first one is simple fread() fwrite() to get the general idea accross, the second need...'

Uus lehekülg

This practice is about writing data in binary format.

== Task ==

There are two tasks; the first one is simple fread() fwrite() to get the general idea accross, the second needs some thinking.

=== Runtimes ===

* Write a program which counts and prints how many times it has been run.
** Save the amount of runs into a file named runtimes.dat
** If the file is missing, write a binary 1 into the file, save and exit.
** If the file exists, read the count from the file, increment it, print it and write the new count into the file before exiting.

=== Array to file and from file ===

Here we could also learn using [http://linux.die.net/man/3/getopt getopt()] function, if task seems too simple.

* If the program starts without command line options, show help
* If program is run with
table -c filename.dat -n 10
: Create 10x10 element 2d array (okay to create just a multiplication table here) and write it into file named filename.dat (save size, then elements)
* If program is run with
table -r filename.dat
: Open the file, read the array dimensions if stored, show the array on the screen.
äidake tabel ekraanile.

== Hints ==

* It is advisable to store the table so that the first 4 bytes of the file hold the table dimensions, then the array elements would follow.
* If the numbers in file are human-readable you are doing the binary wrong.

Writing and Reading Binary Data (ITS8020) - Redigeerimiste ajalugu

Irve: Uus lehekülg: 'This practice is about writing data in binary format. == Task == There are two tasks; the first one is simple fread() fwrite() to get the general idea accross, the second need...'