14 Aug
2011
14 Aug
'11
7:12 p.m.
Sven Mascheck wrote:
see "Setting Up Unix" in the 7th ed man,
vol2b:
"The system as distributed has all of the binaries in /bin. Most of
them should be moved to /usr/bin, leaving only the ones required for
system maintenance (such as icheck, dcheck, cc, ed, restor, etc.)
and the most heavily used in /bin. This will speed things up a bit
if you have only one disk, and also free up space on the root file
system for temporary files."
- Some are certainly required in /bin because /usr/bin
might be on a separate disk. So this certainly includes
all important diagnostic and repair tools.
(And keep in mind that pwd, echo and test were not built
into the 7th ed Bourne shell, yet.)
But which binaries "could" be moved to /usr/bin then?
Out of curiosity I had a look for other (strict) criteria
apart from that you certainly always want to have the
diagnostic+repair tools available in case of problems.
- Some commands are strictly required in /bin because of
hardcoded exec() paths: getty(8) execs to /bin/login,
mv(1) requires /bin/cp,
while other commands interestingly try to exec in both
directories, rm(1) (-r) does so with "rmdir", tar(1) with
"mkdir", bc(1) with "dc", and refer(1) with "sort".
find(1) requires "pwd", but uses popen().
- the absolute minimum in /bin to boot is actually
sh
(because mount is in /etc),
For going multiuser you also need the hardcoded
login
And for getting all diagnostic messages (e.g. /etc/rc)
when going multiuser - with a separate /usr disk -
you need
echo, cat, rm, date
- If you don't want to mess around with temporary copies of
binaries, you need especially for mv :)
cp
- Searching the commands code for hardcoded paths also yields
newgrp, as, cc, ld, pwd,
BTW, the System III distribution had these in /bin, AFAIK,
acctcom chmod diff find ln nm rm strip touch
adb chown dirname grep ls nohup rmail stty true
ar cmp du kas mail od rmdir STTY tty
as cp echo kasb make passwd rsh su uname
basename cpio ed kill mesg pdp11 sed sum vax
bs crypt env kun mkdir pr sh sync wc
cat date expr kunb mv ps size tail who
cc dd false ld newgrp pwd sleep tee write
chgrp df file line nice red sort time
I agree they knew better than me anyway.
So I guess just the above,
minus the SysIII-only commands,
plus the 7thEd-only commands
might be just right for /bin, and that's
ar chgrp date echo icheck mkdir ps sh tail
as chmod dc ed kill mv pwd size test
at chown dcheck false ld ncheck restor sleep touch
bc clri dd file ln newgrp rm sort true
cat cmp df find login od rmdir stty tty
cc cp du grep ls passwd sed su