Tiny Shell

Description

• A simple Unix shell that supports jobs control.
• The shell works through three main task: (1): parse the command to extract the executable name and the command-line options. (2): execute the command by creating a child process then run it. (3): reap the processes after terminating.
• It's the 5th lab of 15-213: Introduction to Computer Systems.
• You can read the specifications with this writeup.

How to use it?

First use the following commands to run the shell:

• git clone https://github.com/Zaher1307/tiny-shell
• make
• ./tsh

Tiny-shell supports mainly four built-in commands as follows:

• quit: terminate the shell.
• jobs: list all running background jobs.
• bg <job>: continue the <job> in background. The arguemnt <job> can be either a PID or JID.
• fg <job>: continue the <job> in forground. The arguemnt <job> can be either a PID or JID.

The shell can be used to run any other command by typing the absolute path of its executable, for instance, the following example runs the echo command:

• tsh> /bin/echo "hello, world!"

note: tiny-shell doesn't support pagers.

How to test it?

• traces contain trace files provided with lab-handouts.
• tests contain executable files used in the test provided with lab-handouts.
• Run each trace on tshref and tsh then compare the outputs.

For example, you can run trace trace14 on tsh by using the following command:

make test14

You can run trace14 also on tshref by using the following command:

make rtest14

Source:

• job.c: contains the data structure that keeps track of the created jobs and store its data.
• signal_handlers.c: contains the implementation of the customized signal handlers.
• helper_wrapper_functions.c: contains wrappers and helpers for the used system calls.
• shell_command_line.c: contains the functions that parse and evaluate the commands.
• sdriver.pl: program used to run the traces on my shell.
• tshref: reference tsh program provided with lab-hanouts to compare tsh outputs with.