ulimit behaves oddly for undefined limits

[Matthew Vernon]

Configuration Information [Automatically generated, do not change]:
Machine: powerpc
OS: darwin7.0
Compiler: gcc
Compilation CFLAGS: -arch i386 -arch ppc -g -Os -pipe -no-cpp-precomp -arch 
i386 -arch ppc -pipe  -DPROGRAM='bash' -DCONF_HOSTTYPE='powerpc' 
-DCONF_OSTYPE='darwin7.0' -DCONF_MACHTYPE='powerpc-apple-darwin7.0' 
-DCONF_VENDOR='apple' -DSHELL -DHAVE_CONFIG_H -DMACOSX   -I.  
-I/SourceCache/bash/bash-29/bash -I/SourceCache/bash/bash-29/bash/include 
-I/SourceCache/bash/bash-29/bash/lib -arch i386 -arch ppc -g -Os -pipe 
-no-cpp-precomp -arch i386 -arch ppc -pipe
uname output: Darwin genghis.vet.cam.ac.uk 7.3.0 Darwin Kernel Version 7.3.0: 
Fri Mar  5 14:22:55 PST 2004; root:xnu/xnu-517.3.15.obj~4/RELEASE_PPC  Power 
Macintosh powerpc
Machine Type: powerpc-apple-darwin7.0

Bash Version: 2.05b
Patch Level: 0
Release Status: release

Description:
Under an operating system where RLIMIT_AS is undefined, ulimit -v
appears to produce useful output. 

If you try and set ulimit -v, you get the exceedingly unhelpful:
-bash: ulimit: virtual memory: cannot modify limit: Invalid argument

What should happen is that bash should tell you that it can't modify
that limit on this platform. You might like to consider whether ulimit
-v should say something similar, too. Furthermore, should ulimit -a
really mention the "virtual memory" limit on such systems?

Repeat-By:

1) pick an appropriate OS. MacosX would do
2) run "ulimit -v":
genghis:~/phd/code matthew$ ulimit -v
14336
3) run "ulimit -v 100":
genghis:~/phd/code matthew$ ulimit -v 100
-bash: ulimit: virtual memory: cannot modify limit: Invalid argument
4) run "ulimit -a":
genghis:~/phd/code matthew$ ulimit -a
[uninteresting lines elided]
virtual memory        (kbytes, -v) 14336

Regards,

Matthew

-- 
Matthew Vernon MA VetMB LGSM MRCVS
Farm Animal Epidemiology and Informatics Unit
Department of Clinical Veterinary Medicine, University of Cambridge