Simple-shell-in-C

An interactive shell in C

Author

Man Yuet Ki Kimmy

Features

Interactive command

e.g.

ls -la

Excute valid program with absolute path or relative path

/home/word/a.out

./a.out

Interrupt signal depends on executed program

If a program is executed in this shell, the reaction after Ctrl-C depends on the feature set in this executed program.

Pipe command

cat a.txt | grep t | wc -l

Exit shell

This shell program ignore Ctrl-C. You can only terminate with

exit

It release all its resources and then terminate.

Showing executing details

Use timeX before the command to show the terminated process's ID, program name (without the path), user cpu time and system cpu time. e.g. Input

timeX cat a.txt | grep t | wc -l

Output

10
(PID)89  (CMD)cat  (user)0.001 s  (sys)0.000 s
(PID)90  (CMD)grep  (user)0.001 s  (sys)0.000 s
(PID)91  (CMD)wc  (user)0.001 s  (sys)0.000 s

Execute program in the background

Add & behind the command needed to be executed in the background.

vi &

Invalid input

If invalid input is inputted, error message is given.

Usage

gcc 3230shell.c -o 3230shell
./3230shell

Copyright 2022 Man Yuet Ki Kimmy