#rshell

This is a very, very basic unix-shell, like bash, but less functional for now. It can almost execute everything bash does, as long as it is already a /bin/ executable, along with built-in exit and cd commands.

Compound commands are supported, but only with the &&,||, and ; connectors. It is worth noting that when stringing commands together, there is no inherent "order of operations"; commands connected by && only rely on whether the previous argument succeeded or not, while || relies on its failure.

Input/output redirection and piping are supported to a limited extent as outlined in the Bugs & Other Documentation section below.

cd only takes a single argument, as in cd fakedir; anything more than this will give an error as to the number of arguments.

##Installation

git clone https://github.com/cbarb005/rshell.git
cd rshell
git checkout hw0
make
bin/rshell

##Bugs & Other Documentation

Sometimes, a phantom empty line appears after executing a command. So far, this only seems to happen with compound commands, and not consistently.

If not a valid command , such as lss || echo hello, perror will return a message, but will NOT echo. This only occurs with this specific connector.

A statement like pwd && && && && && && ls will no longer run. Commands may no longer start or end with a connector.

Currently, input/output redirection only supports a single operation per command, unless a connector is used. Occasionally, when running wc < somefile.txt, the space at the very beginning of the returned line is missing.

Piping and connectors are not simultaneously handled, so a command such as ls | ls && echo bye must be instead given as ls | ls and echo bye. Multiple pipes as of this moment are not supported, and is a major bug in this program.

cd has a bug in which after a nonexistent directory passed in. The program returns an error message as expected, but afterwards, attempts such as cd .. and cd dir also return the same error, until the command cd - is used, thus restoring all the previous commands.

After stopping a program with ^Z and resuming it with either fg or bg, or resuming and then ^C, it does not automatically return to the prompt; you must press enter. Sometimes, fg and bg break and the function hangs. This does not happen consistently. On its own, ^C works fine, but as mentioned above, may get stuck when used with fg or bg.

For ls, any combination of -l and -R does not work. They work fine on their own and each combined with -a, but -R doesn't play well with others. Errors for stat may appear even if everything is output correctly.

Occasionally, the colors on ls may mess up output. For this reason, colored output for ls is available by using the flag "-cc" to enable colors for a single execution of ls.