Tag Archives: shells

Variable sizes in KSH

15/02/2011 – 09:51

It looks like the POSIX shell doesn’t support variable sizes greater than 2 Gigabytes. In the following example, the LIMIT variable is of 1 Gbyte, and the VALUE is 4 GBytes. # LIMIT=1073741824 # VALUE=4294967296 # if [ $LIMIT -lt $VALUE ] > then > echo “exceeds limit” > else > echo “passed” > fi [...]

By Viktor Balogh | Posted in Languages and Scripting, System Internals, Workstations | Also tagged , , , , , , , | Comments (0)

UNIX95 variable influences to the ps command

20/01/2011 – 15:32

Setting UNIX95 to some value (it doesn’t matter what it is) changes the behavior of the ps command to use the XPG4 environment instead of the HPUX environment. You can see all the different command line options and the XPG4 behaviors by looking at the man pages (e.g. man ps). Several options like ps -o [...]

By Viktor Balogh | Posted in HP-UX system administration, Languages and Scripting, Monitoring, Resource management | Also tagged , , , , , , , | Comments (5)

Correct usage of ulimit

29/04/2010 – 09:07

The “ulimit” and “limit” commands are often built into the shell, but there may exist some binaries with the same name. For example: # /usr/local/bin/bash bash> type ulimit ulimit is a shell builtin bash> which ulimit /usr/bin/ulimit

By Viktor Balogh | Posted in HP-UX general | Also tagged , , , , , , | Comments (1)

Advanced scripting – changing the UID of a user

25/11/2009 – 15:29

At one of our customer we will have an monstre’ UID-consolidation projekt in the near future. For this purpose I’ve written a script to enlighten our task. Most of you thinks at it a an over-complicated (usermod && find …. chown …) job, but my script has undergone some performance optimisation too: it starts parallel [...]

By Viktor Balogh | Posted in Languages and Scripting | Also tagged , , , , , | Comments (3)

Differences between shells

16/07/2009 – 23:33

Here is a comparison matrix I’ve found on www.faqs.org: sh csh ksh bash tcsh zsh rc es Job control N Y Y Y Y Y N N Aliases N Y Y Y Y Y N N Shell functions Y(1) N Y Y N Y Y Y “Sensible” Input/Output redirection Y N Y Y N Y [...]

By Viktor Balogh | Posted in HP-UX general, Languages and Scripting | Also tagged , , , , , | Comments (3)