minsh: Mini Shell

A minimum shell developed for course CES-33 at ITA, SP, BR.

Code organization

• interactive: Functions related to reading input and displaying information
• internal: Define internal commands exit, jobs, fg and bg.
• parser: Parser and Lexer used to parse a command
• system: Interfaces with the OS - system calls to execute and manage jobs.
• types: Data structures program, job and stringarr.

Features

• Output redirecting (>)
• Input redirecting (<)
• Pipelining (|)
• Running in background (&)
• Signal handling (Ctrl+C, Ctrl+Z)

Obs: Only the first member of a pipeline can redirect input. Only the last member can redirect output.

Internal commands

• jobs: Lists running jobs
• bg [n]: Takes job n to background, defaults to 0
• fg [n]: Brings job n to foreground, defaults to 0

Preparing the environement

A docker container with the necessary dependencies can be run with docker compose run main. Docker server v20.10.14 was used during development.

Building and Running

Build with make debug or make release. Run with ./bin/minsh.

Example inputs

/bin/ls | /usr/bin/sort -r | /usr/bin/tail -n 3 > outtest
/bin/sleep 5 &

Testing

Running the script ./test/test-1.sh will run the minishell with a prepared input and compare the result generated to test-1.output.txt with the test-1.exepected.txt.

Empty script output means success (real output matches expected).