Warning: Do not use this code in production environments or as a drop-in replacement for your other Unix utilities.

On Sunday, I thought about making an assembly program to learn assembly by doing. I thought of the cat program because I thought it wouldn't be too difficult. It took until the next day that I got it to work.

Then I thought: What if I try to make other Unix programs?
So far, I have made cat and mkdir, but the mkdir source is similar enough that I also got it to assemble to touch, rm, and rmdir. They don't have any command-line arguments, so you can't execute something like

Code:

or

Code:


The repository is located on the Github repo, so suggestions and feedback are welcome! All you need to install is NASM, GNU ld, and Make.

Minor update:
Add the -f command to suppress errors on rm, rmdir, touch, and mkdir.
Made it so mkrndirfile/ doesn't need one assembly file for each binary.

I plan to get back to work on this, as my work was halted due to school and waning willpower.

Kind of major update:
I got the idea of removing the section headers in the executables because they take up over 100 bytes! I made strip-secthead, which does this for me. Here is the size difference I achieved:

Code:

DO NOT use this on non-executable files, because they will be corrupted, and there are almost no safeguards.

Update:
I deprecated strip-secthead and the beta of head. Instead, I made my own ELF header and embedded the exit code in the header. This is the current size listings:

Code:

I am planning to make another program soon, but that is TBD because I want to think of one that will challenge me.

Yet another update:
I made yes, and I reduced the program sizes even further.

Code:

No, yes didn't challenge me, but I thought it would be quick and painless to do. As always, my changes are welcome on Github (listed above) so you can use the code if you want.

Update:
I made clear. It may or may not work on your terminal, so you should run this command and edit clear.asm appropriately. With the default configuration, it takes up 137 bytes.

Code:


I also made an "experimental" port of the current programs to the Linux X32 ABI. Here is a comparison of the sizes of the programs.

Code:

Note: You will probably need to edit your GRUB configuration for these to work.