February 2011 – Program Creek

Java: get a set of random numbers from a specified range

October 27, 2015February 20, 2011 by ProgramCreek

This is a method that accepts a range (max) and a number (n), returns an array of n random numbers. n: size of random number array max: largest available number (exclusive) For example: Input: n=5, max=100 Output: an array containing 5 random numbers whose range is from 0 to 99. public static HashSet<Integer> getNRandom(int n, … Read more

Double star after type and before variable

February 14, 2011February 14, 2011 by ProgramCreek

What does ** mean in the following code?

char **argv;

It declares argv as a pointer that points to a char pointer. It is equivalent to the following code.

char *argv[];

Linux Pipe for Communication Between Java and C++ program

July 26, 2014February 12, 2011 by ProgramCreek

Pipe is neat. A pipe is a way to connect the output of one program to the input of another program without any temporary file. This simple test contains a Java program and a C++ program. The output of Java program is used as input for “wc” command, and the output is then used by … Read more

Linux Shelling Programming Warm-up Example â€“ $?

December 14, 2014February 12, 2011 by ProgramCreek

This shell program mainly demonstrate how to use $? to find out the exit status of command.

After a command executes, if you input to terminal: echo $?, you will get 0 or 1 to indicate the status of execution.

The following is a simple program with comments.

Linux Process Programming – fork()

February 12, 2011 by ProgramCreek

What is a process?

In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently.

How Compiler Works?

December 31, 2012February 11, 2011 by ProgramCreek

How compiler works is not easy to explain in one sentence. The best way is to use an example. A compiler is a computer program that transforms source code written in a high-level programming language into a lower level language. Basically, a compiler consists the following phases: Lexical Analysis, Syntax Analysis, Semantic Analysis, IR Generation, … Read more