can someone help me write a c shell implemented in a unix based platform, that supports the following internal commands: cd- change the current default directory to. If theargument is not present,...

can someone help me write a c shell implemented in a unix based platform, that supports the following internal commands:

• cd- change the current default directory to. If theargument is not present, report the current directory. If the directory does not exist an appropriate error should be reported. This command should also change the PWD environment variable.


• clr - clear the screen.


• dir- list the contents of directory


• environ - list all the environment strings


• echo - display on the display followed by a new line (multiple spaces/tabs may be reduced to a single space)


• help - display the user manual using the more filter


• pause - pause operation of the shell until 'Enter' is pressed


• quit - quit the shell


• The shell environment should contain shell=/myshell where/myshell is the full path for the shell executable (not a hardwired path back to your directory, but the one from which it was executed)

All other command line input is interpreted as program invocation which should be done by the shell
forking and execing
the programs as its own child processes. The programs should be executed with an environment that contains the entry: parent=/myshell where/myshell

The shell should alos support bash mode, i/o redirections, background execution and miscellaneo, along with a user manual

Thank you