A shell completely written in C. Supports bg/fg jobs, ';' separated list of commands, io redirection, pipes, escaping quotes and more.

Features

The following shell builtins were implemented:

• cd (supports absolute / relative paths)
• pwd
• echo
• history (stored last 20 commands, accessible with the up arrow)
• exit
• pinfo (gives detailed info about any process given it's pid)
• ls (yes, it was implemented again, supported '-a' and '-l' flags)
• {un}setenv (allowed removal and creation of environment variables)
• jobs (like ps)
• kjob (sends a signal to a process)
• fg / bg (moves a process to foreground or background)
• overkill (stops all background processes)
• ... (and some more)

Any external command was executed using the exec syscall

The following features were implemented:

• semicolon(;) seperated list of commands can be passed, whitespace is ignored
• Execution of system commands with or without arguments, in background or foreground
• Notifying when and how the background process terminated
• Input and output redirection, including appending to a file
• Piping of commands
• Handling SIGINT [C-c] and SIGTSTP [C-z] signals
• Command recall using up arrow key
• echo supports printing environment variables
• Spaces are escaped within quotes. i.e., vim "bad name.txt" will work as expected

Image(s)

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Code

The code, along with instructions to build and use it can be found on github, at yoogottamk/ysh.