topic Re: HISTSIZE Shell Variable in Operating System - HP-UX

HISTSIZE Shell Variable

Raymond Ford — Thu, 06 Feb 2003 13:09:49 GMT

On both HP-UX 11 and 11i systems the root's .profile reflects SHELL=sh, HISTFILE=(the correct path & filename), HISTSIZE=800, HISTSAVE=400. (Other parameters in this file are omitted.) The root user enters the "history" command and output yields only 16 previous commands. When the same parameters are run from etc/profile, 26 commands are recalled. Can anyone explain? Thank-You.

Re: HISTSIZE Shell Variable

Jose Mosquera — Thu, 06 Feb 2003 13:17:59 GMT

Hi,

Try these sintax into the root .profile:

EDITOR=vi; export EDITOR

HISTFILE=/.sh_history; export HISTFILE
HISTSIZE=800; export HISTSIZE

Rgds.

Re: HISTSIZE Shell Variable

harry d brown jr — Thu, 06 Feb 2003 13:18:17 GMT

What does HISTSAVE do?

You might have a corrupted history file, try "mv"'ing it and starting over?

Also, after the root user log's in, echo $HISTFILE, $HISTSIZE

live free or die
harry

Re: HISTSIZE Shell Variable

James R. Ferguson — Thu, 06 Feb 2003 13:21:12 GMT

Hi:

Make sure that 'EDITOR=vi' and that you have exported your variables. Verify this with 'env'.

Regards!

...JRF...

Re: HISTSIZE Shell Variable

Raymond Ford — Thu, 06 Feb 2003 14:02:31 GMT

The 3 suggestions above are appreciated and were tested, though they were already in effect in .profile. Could another env variable or the type of shell we use be a factor? I'm told that "sh" is not Bourne but more of a POSIX shell. The operating systems were recently upgraded from 10.20. Could an error have occurred at that stage? Could a kernel setting interfere? We are still researching to see if problem persists using Korn shell. Thanks again.

Re: HISTSIZE Shell Variable

Bill Hassell — Thu, 06 Feb 2003 14:08:21 GMT

It's important to note that HISTSIZE, HISTFILE (and the meaningless variable HISTSAVE) are not part of a standard HP-UX /etc/profile or .profile so some sysadmin has added these values. To get command history working, you need HISTFILE defined (and EDITOR to make sure the expected history shortcuts work as expected).

The man page for sh-posix (and ksh) define the rules about HISTSIZE and the maximum number of displayed commands. Note that multiple shells run by the same user (using the same $HISTFILE) will see a certain amount of conflicts as each shell tries to manage the same history file. If you remove the definition for HISTFILE, you'll get a default history of 128 lines.

Re: HISTSIZE Shell Variable

Pete Randall — Thu, 06 Feb 2003 14:08:30 GMT

Terrence,

Serious consequences can result from changing root's shell - if that's what you were implying, don't do it!

Pete

Re: HISTSIZE Shell Variable

Bill Hassell — Thu, 06 Feb 2003 14:11:49 GMT

In HP-UX, the sh shell is a POSIX shell (just like ksh and bash and relatives). To locate the (deprecated) Bourne shell, use /usr/old/bin/sh) but do not change root's shell from /sbin/sh. Standard users get /usr/bin/sh which is the standard POSIX shell in HP-UX. Most Korn shell users cannot tell the difference between the HP-UX POSIX shell (man sh-posix) and ksh except sh-posix has more features (like ulimit -a).

Re: HISTSIZE Shell Variable

Raymond Ford — Thu, 06 Feb 2003 14:26:48 GMT

To answer Harry, I searched "HISTSAVE" on this site and found "history is not a command but a predefined alias to: fc -l and the man page for sh-posix says that this defaults to -16 (the most recent 16 lines). If you specify a larger history value (ie, history -150) than $HISTSIZE, only the most recent $HISTSIZE lines will be displayed.

I think our problem was not adding the dash before the # of commands we wanted to display! Will check to see. Thank-you everyone.

Thanks to all.

Re: HISTSIZE Shell Variable

harry d brown jr — Thu, 06 Feb 2003 15:13:28 GMT

I use HISTSIZE=50000. Yeah, it can consume some space, but a meg is less than 5 cents anyways so I don't worry about.

Re: HISTSIZE Shell Variable

Bill Hassell — Thu, 06 Feb 2003 15:58:41 GMT

Correct. history is indeed an alias for fc. A really good tool to remember is the 'type' command. So for history:

type history
history is an exported alias for fc -l

type (and the base command whence) totally obsolete which and whereis because only type and whence will tell you what the shell is going to do with a particular string. For example:

type ls
ls is an alias for /usr/bin/ls -aF

Hummmm, so if I unalias ls then:

unalias ls
type ls
ls is /usr/bin/ls

A lot of Trojan horses will masquerade as a normal command but type will show you is really going to happen.

I get tired of typing 'history' so I do this:

alias h="fc -l"

and then I can type:

h

or

h -50

and see the history quickly.