Training, Open Source computer languages
PerlPHPPythonMySQLApache / TomcatTclRubyJavaC and C++LinuxCSS 
Search for:
Home Accessibility Courses Diary The Mouth Forum Resources Site Map About Us Contact
For 2023 (and 2024 ...) - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
max array size

Posted by chuckster (chuckster), 24 March 2003
I am trying to find out what is the max array size to read in a directory. This is on a sun box.

Posted by admin (Graham Ellis), 25 March 2003
A list in Perl (used to be called an array) is limited in the number of elements it can contain only by the addressing range of the system, and be the amount of memory and swap space that's available to your process.   In other words, if you're looking to hold a list of all the file names in a directory in a list, you should have no problem at all.



for ($k=0; $k<$ARGV[0]; $k++) {
       $list[$k] = $k;

print "OK\n";

[localhost:~/mar03] graham% ./biglist 1000
[localhost:~/mar03] graham% ./biglist 10000
[localhost:~/mar03] graham% ./biglist 100000
[localhost:~/mar03] graham% ./biglist 1000000
[localhost:~/mar03] graham% ./biglist 10000000
[localhost:~/mar03] graham%

I could really here the disc swapping in the last example ...

Test program run on a laptop running OSX; I'm very familiar with Sun and Solaris - same rules / criteria apply.

Posted by admin (Graham Ellis), 25 March 2003
It's probably way beyond what the original questioner expected, but I thought I would run my test program asking for an even bigger list:

[localhost:~/mar03] graham% ./biglist 100000000
*** malloc[293]: error: Can't allocate region
Out of memory!
[localhost:~/mar03] graham%

To give you an idea, it ran for quite a while, occupied 211M of my 256M of physical memory and well over 3Gbytes of swap space before it crashed out.

Posted by chuckster (chuckster), 26 March 2003
Thank you for those answers. Much appreciated  

This page is a thread posted to the opentalk forum at and archived here for reference. To jump to the archive index please follow this link.

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2024: Well House Manor • 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01144 1225 708225 • FAX: 01144 1225 793803 • EMAIL: • WEB: • SKYPE: wellho