Unix 5.4 and ulimit

[Dave McCracken]

guy at auspex.auspex.com (Guy Harris) writes:

>As S5R4's resource-limiting code is derived from 4.3BSD's to a large
>degree, and as the ulimit is, I think, the same as the RLIMIT_FSIZE
>limit, if you wish can you just say "ulimits suck" and set the ulimit to
>RLIMIT_INFINITY, i.e. 0x7fffffff (at least in 4.3BSD and many
>derivatives), and not have a ulimit *at all*?

Yes, you can.  There is even a special syntax in the shells' 
ulimit commands that you can say 'unlimited' instead of a number,
and it will set the appropriate resource limit to 0x7fffffff.
Note that you can not generate that value with a numeric argument
to ulimit since you have to specify it in blocks, and the shell
will multiply it out to bytes.

There is also a gotcha with this feature.  If you set ulimit to
'unlimited', invoking ulimit with no arguments will print 'unlimited',
which may break some shell scripts which assume the output is a
number and try to do numeric things to it.


--
Dave McCracken      dcm at dell.dell.com      (512) 343-3720
Dell Computer       9505 Arboretum Blvd    Austin, TX 78759-7299