Question

you are to create a simple “shell” for Linux systems. A shell is a
command interpreter whose main function is to get and execute the next user-specified command.

Required Tasks
You must write the shell in C/C++ for Linux systems, and the shell must have the following
functionalities (or features):

1. can use command chdir to change to a given directory.

Answer 1

First lets create a shell in Linux. Follow the below steps.

$ vi simpleshell.sh (Note: here vi is an editor to create a file, simpleshell.sh is shell name)

now write the C program in the shell as shown below

#include<stdio.h>
#include<unistd.h>
int main()
{
char s[100];
  
// printing current working directory
printf("%s\n", getcwd(s, 100));
  
// using the command
chdir("..");
  
// printing current working directory
printf("%s\n", getcwd(s, 100));
  
// after chdir is executed
return 0;
}

Now press Esc and type :wq to save the file.

So now, the shellscript simpleshell.sh is ready.

Now to run the shell script, use the command below

$ ./simpleshell.sh ( This runs the shell script and the chdir() changes the dir)