sushi is a small, public domain shell for *nix systems written in POSIX C89,
intended for interactive use.

so far, sushi supports:
- executing commands and pipelines of arbitrary length
- redirection to/from any files/file descriptors and closing file descriptors
via redirection
- tilde and pathname expansion
- builtins
- pledge(2) support on OpenBSD

sushi is still in early development and is NOT compliant with any POSIX
standard.

sushi has been tested to run on the following platforms:
- Void GNU/Linux (musl variant), x86_64
- Void GNU/Linux (musl variant), x86_64, linked against dietlibc
- OpenBSD, 64-bit RISC-V

sushi has been tested to compile and run successfully with:

- GCC (https://gcc.gnu.org)
- Clang (https://clang.llvm.org)
- TCC (https://bellard.org/tcc)
- PCC (http://pcc.ludd.ltu.se)
- cproc (https://git.sr.ht/~mcf/cproc)

------------------------------------------------------------------------------
building

most commonly, a simple:

$ make

will suffice. if your system doesn't have 'cc' as an alias to a C compiler,
you'll have to specify it manually:

$ make CC=gcc

to link against dietlibc, you'll need to link it against dietlibc's libcompat.a:

$ make CC='diet gcc' SRC='sushi.c <path-to-libcompat.a>'

for example:

$ make CC='diet gcc' SRC='sushi.c /opt/diet/lib-x86_64/libcompat.a'

this is because dietlibc only provides the (now standardized by POSIX) getline()
in its libcompat sub-library.

------------------------------------------------------------------------------
configuration

sushi has some compile-time options that you can tweak by
commenting/uncommenting the macro definitions at the top of sushi.c.

as an example, to build with pledge(2) support for OpenBSD, edit the line
with the ENABLE_PLEDGE definition:

-/* #define ENABLE_PLEDGE */  /* enable usage of OpenBSD's pledge(2). */
+#define ENABLE_PLEDGE        /* enable usage of OpenBSD's pledge(2). */

and rebuild the program.