The TRagically Awesome SHell-- tRash --is a command-line interpreter based off the sh shell.
It reads and executes commands from the standard input or the terminal by default,
or from a file specified as a command line argument to the shell.
tRash is capable of running any valid executable with options within a machine.
If the absolute path to a particular file with execute permission(s) is not specified,
tRash searches all directories in the $PATH available to it to find a valid
absolute path to the command, except in the case where the command is a built-in,
then it is handled immediately and execve is not called.
It can be built and run on any computer with C compiler, and accessed via a terminal.
Dependencies include make, gcc, gzip, mandb. Ensure you have them installed.
- Clone this repository and navigate into the local
tRash/build/directory
git clone https://github.com/OvyEvbodi/tRash/ tRash ;
cd tRash/build/ ;- To build
tRashand run it in the current directory, use the following command:
make- For the complete installation, and to add
tRashto a standard location and install the manpage, run:
make install- To uninstall the
tRashbinary, run:
make uninstall- For a complete clean of the
tRashbinary as well as all object files, run:
make clean- For help, checkout the manpage:
man tRashtRash can be invoked interactively or non-interactively.
In interactive mode, it is invoked by calling its name in the current directory:
./tRashIf the executable has been added to a directory present in $PATH, you could run:
tRashA prompt is displayed and the user enters in commands from the terminal, ending with a new line or an EOF.
In non-interactive mode, another shell could read and execute commands, and the output
is piped into the input stream of the TRagically Awesome SHell.
The shell exits after all the commands piped into it have been executed.
Commands could also be contained in a file with read permission, provided as a command line argument to the program.
If more than one argument is provided, the first one is assumed to be the file
with the commands to be executed, separated by a new line or semi-colon, and ending with an EOF.
The semi-colon ; is used to seperate commands on the command-line.
Each command is ended with a semi-colon, and the succeeding command(s) follows.
Comments are started with a hash symbol #. Any data that follows the # is ignored
only if the hash symbol follows a non-printable character, otherwise the symbol loses its special meaning.
All data that succeed a valid # are treated as command-line comments and therefore are not processed.
These provide some extra flexibilty.
| Built-in | Details |
|---|---|
cd [directory] |
Changes the users current working directory and updates $PWD and $OLDPWD. |
exit [status] |
Exits the current instance of the shell process. |
env |
Prints a list of the currently set environment variables available to the shell. |
setenv NAME VALUE |
Sets a new environment variable for the current shell process and sub processes, with NAME and VALUE in the format NAME=VALUE. |
unsetenv NAME |
Removes an environment variable whose name matches NAME from the list of environment variables available to the shell. |
| Code | Meaning |
|---|---|
| 0 | For success. |
| 1 | Usage, syntax, or processing errors. |
To report bugs and make contributions or feature requests, click here
The original version of tRash was made for educational purposes and resticted function use to the following.
Every other function was created from scratch.
- List of allowed functions and system calls
access (man 2 access) chdir (man 2 chdir) close (man 2 close) closedir (man 3 closedir) execve (man 2 execve) exit (man 3 exit) _exit (man 2 _exit) fflush (man 3 fflush) fork (man 2 fork) free (man 3 free) getcwd (man 3 getcwd) getline (man 3 getline) getpid (man 2 getpid) isatty (man 3 isatty) kill (man 2 kill) malloc (man 3 malloc) open (man 2 open) opendir (man 3 opendir) perror (man 3 perror) read (man 2 read) readdir (man 3 readdir) signal (man 2 signal) stat (__xstat) (man 2 stat) lstat (__lxstat) (man 2 lstat) fstat (__fxstat) (man 2 fstat) strtok (man 3 strtok) wait (man 2 wait) waitpid (man 2 waitpid) wait3 (man 2 wait3) wait4 (man 2 wait4) write (man 2 write)