Simple SHELL

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Your shell should work like this in interactive mode:

$ ./hsh
($) /bin/ls
hsh main.c shell.c
($)
($) exit
$

But also in non-interactive mode:

$ echo "/bin/ls" | ./hsh
hsh main.c shell.c test_ls_2
$
$ cat test_ls_2
/bin/ls
/bin/ls
$
$ cat test_ls_2 | ./hsh
hsh main.c shell.c test_ls_2
hsh main.c shell.c test_ls_2
$

Our SHELL should:

->Display a prompt and wait for the user to type a command. A command line always ends with a new line.
->The prompt is displayed again each time a command has been executed.
->The command lines are simple, no semicolons, no pipes, no redirections or any other advanced features.
->The command lines are made only of one word. No arguments will be passed to programs.
->If an executable cannot be found, print an error message and display the prompt again. Handle errors.
->Handles the “end of file” condition (Ctrl+D)

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Functions and System Calls

• access (man 2 access)
  
• chdir (man 2 chdir)
  
• close (man 2 close)
  
• closedir (man 3 closedir)
  
• execve (man 2 execve)
  
• exit (man 3 exit)
  
• _exit (man 2 _exit)
  
• fflush (man 3 fflush)
  
• fork (man 2 fork)
  
• free (man 3 free)
  
• getcwd (man 3 getcwd)
  
• getline (man 3 getline)
  
• getpid (man 2 getpid)
  
• isatty (man 3 isatty)
  
• kill (man 2 kill)
  
• malloc (man 3 malloc)
  
• open (man 2 open)
  
• opendir (man 3 opendir)
  
• perror (man 3 perror)
  
• read (man 2 read)
  
• readdir (man 3 readdir)
  
• signal (man 2 signal)
  
• stat (__xstat) (man 2 stat)
  
• lstat (__lxstat) (man 2 lstat)
  
• fstat (__fxstat) (man 2 fstat)
  
• strtok (man 3 strtok)
  
• wait (man 2 wait)
  
• waitpid (man 2 waitpid)
  
• wait3 (man 2 wait3)
  
• wait4 (man 2 wait4)
  
• write (man 2 write)
  

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Tasks to be done:

• handle the PATH
• modified shell functions
• Handle getline function
• handle arguments for the built-in exit
• Handling memory leaks
• using valgrind to chec errors