Instructions Write a mini shell program (in C/C++) called cwushell under Linux/MacOS. The shell reconnizes the following internal commands: 1. exit [n] -- terminates the shell, either by calling the exit() standard library routine or causing a return from the shell's main(). If an argument (n) is given, it should be the exit value of the shell's execution. Otherwise, the exit value should be the value returned by the last executed command (or O if no commands were executed.) 2. prompt [new_prompt] will change the current shell prompt to the new_prompt. The default prompt should be cwushell. Typing prompt should restore the default shell prompt. 3. cpuinfo -switch will print on the screen different cpu related information based on the switch. The different switches to be implemented are: 1)-c- will print the cpu clock (e.g. 3.2 GHz), 2) -t-will print the cpu type (e.g. Intel) and 3) -n- will print the number of cores (e.g. 8). 4. meminfo -switch will print on the screen different memory related information based on the switch. The different switches to be implemented are: 1)-t-will print the total RAM memory available in the system in bytes, 2) -u -will print the used RAM memory and 3) --- will print the size of the L2 cache/core in bytes. 5. all other existing shell commands (internal and external Linux commands e.g. Is, cat, pwd, etc.) should also be executed by the cwushell. Notes Error handling should be considered (see erroneous commands, non-existing switches, etc.). For the cwushell a help file (containing all the commands, their syntax and their outcome) should be provided, which should be invoked from the shell using the manual command. For each command a specific help should be invoked if called without a parameter or using -help or -h switches. This will help the user to see how to use the different commands in the cwushell. See for details the Unix/Linux manual pages. The help should be structured/formatted in the same way as used by the man pages. The shell has to receive commands until explicitly the exit is invoked. Please study the behavior or current shells such as bash/tcsh/ksh. It is not required to implement the commands using fork()! For 1-4 the system() function can not be used