[TUHS] /bin/true (was basic tools / Universal Unix)

Ronald Natalie ron at ronnatalie.com
Fri Oct 20 12:05:15 AEST 2017


Of course, 4K is in the noise on a machine with 32 Gig or more of memory.

The old PDP-11 could put a 136 byte executable (assuming the standard UNIX V6 a.out header into two 64 byte chunks of memory.    Not too shabby even in those days.

> On Oct 19, 2017, at 9:31 PM, Lyndon Nerenberg <lyndon at orthanc.ca> wrote:
> 
> 
>> On Oct 19, 2017, at 6:27 PM, Dan Cross <crossd at gmail.com> wrote:
>> 
>> macOS requires you to have a data section aligned to 4K, even if you
>> don't use it. The resulting binary is a little over 8K; again, mostly
>> zeros.
>> 
>> There are parlor tricks people play to get binary sizes down to
>> incredibly small values, but I found the results interesting. Building
>> the obvious C program on a PDP-11 running 7th Edition yields a 136
>> byte executable, stripped. Still infinitely greater than /bin/true in
>> the limit, but still svelte by modern standards.
> 
> No matter how tiny you can make the a.out, the kernel's still going to have to map in at least one page to hold it, so you're eating a minimum of 4K on any modern machine, regardless.



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