01-05-2010
How UNIX/AIX handles a file deep down, say it's being read while another one tries to rename it?
Hi Thinkers,
On AIX 5.3, we have a monitor program that reads the log file and searching for a certain string pattern that we define(say "transactionException"), if it sees it then it will raise an alert by sending an email.
Because the log file XXX.log is rolling into XXX.log.0, XXX.log.1, XXX.log.n...etc when a certain condition(size, time/date) meets, now my question is, is that possible that when the application generates the string "transactionException" and then it got rolled/renamed into XXX.log.0 before the monitor program sees it ? The monitor program is configured to monitor XXX.log file only ?
I am not sure how the monitor program is coded so I'd like to ask this way, if you are developing such monitor tooling, what you'd think to avoid the senario that I described above? I believe this may be to do with how Unix handle file deep down at the very low level ...
Your knowledge on this is much appreciated.
Thanks a ton.
Thegunman
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hi,
perhaps you can answer my question.....;)
How can I check, how many file handles are used and how can i increase the value for maximum file handles??? (3 Replies)
Discussion started by: sjaeger
3 Replies
2. Shell Programming and Scripting
Hi all
I try to execute SSH commands on several hosts in a while-loop.
There seems to be a problem with file-handle, first cycle works correct but no other one will follow due to the while condition is false even that there are many more host entries (lines) in all_hosts.dat.
... (3 Replies)
Discussion started by: DaveCutler
3 Replies
3. Shell Programming and Scripting
Hello,
I have a program which opens a pipe for communication using file handle and forks 5 child processes.
@waitlist = (1,2,3,4,5);
foreach $item (@waitlist) {
pipe *{$item},RETHAND;
unless ($pid = fork()) {
# Child process
print RETHAND... (1 Reply)
Discussion started by: the_learner
1 Replies
4. Shell Programming and Scripting
We have a process that is running out of file handles. Is there some command line way to determine this that we can include into a cron script?
Please let me know
JAK (3 Replies)
Discussion started by: jakSun8
3 Replies
5. Shell Programming and Scripting
Hello guys, thank God that I found this forum.
I hope that someone can help me because I don't have any idea on how to start it. I know that for some of you this is a very simple task but I'm not as advance on shell scripting like many people out there.
I got this file with a permanent... (10 Replies)
Discussion started by: Shark Tek
10 Replies
6. Shell Programming and Scripting
I need to be able to look for the last file in a dirctory in UNIX,
the file satrt with EFT
so this work file=$(ls -tr $EFT*.dat | tail -1) # Select the latest file
my last file is EFT1234.dat
then I need to be able to get a file that I just ftp and rename with this
name EFT1234.dat but... (5 Replies)
Discussion started by: rechever
5 Replies
7. UNIX for Advanced & Expert Users
I'm using Sendmail 8.13.8 on a CentOS 5.5 vServer (Virtuozzo).
I'm using a loop in PHP to send a lot of HTML-mails via sendmail. Each mail is a mail with individual statistics for our users, so its not mass mailing, bcc is not an option.
It all works fine, but when I take a closer look there... (2 Replies)
Discussion started by: ZX81
2 Replies
8. UNIX for Dummies Questions & Answers
Hi All,
I have a unix file which is ceated with variable name, for example:
FIRST_FILE_3456 and next time it will be FIRST_FILE_3457 and so on.
I need to rename this file like PREV_FIRST_FILE_XXXX where XXXX is the variable part of the file FOR Example 3456 or 3457, etc.
Please help to... (4 Replies)
Discussion started by: Mohammad T Khan
4 Replies
9. UNIX for Dummies Questions & Answers
This is a strange one.
We have an issue where our system is leaking SCTP file handles. There are people working on this and in the mean time we have a monitoring script that alarms when we need to perform actions to manually clear them. For testing purposes I want to write a script that... (0 Replies)
Discussion started by: RECrerar
0 Replies
10. Shell Programming and Scripting
Hello All,
Can you help me in writing a script for reading the specific position data in a file and if that data found in that file that particular file should be renamed.
Ex: Folder : C:\\test
and Filename : CLSACK_112214.txt,CLSACK_112314.txt,CLSACK_112414.txt
Contents in the file would... (3 Replies)
Discussion started by: nanduedi
3 Replies
LEARN ABOUT MOJAVE
perlos400
PERLOS400(1) Perl Programmers Reference Guide PERLOS400(1)
NAME
perlos400 - Perl version 5 on OS/400
DESCRIPTION
This document describes various features of IBM's OS/400 operating system that will affect how Perl version 5 (hereafter just Perl) is
compiled and/or runs.
By far the easiest way to build Perl for OS/400 is to use the PASE (Portable Application Solutions Environment), for more information see
<http://www.iseries.ibm.com/developer/factory/pase/index.html> This environment allows one to use AIX APIs while programming, and it
provides a runtime that allows AIX binaries to execute directly on the PowerPC iSeries.
Compiling Perl for OS/400 PASE
The recommended way to build Perl for the OS/400 PASE is to build the Perl 5 source code (release 5.8.1 or later) under AIX.
The trick is to give a special parameter to the Configure shell script when running it on AIX:
sh Configure -DPASE ...
The default installation directory of Perl under PASE is /QOpenSys/perl. This can be modified if needed with Configure parameter
-Dprefix=/some/dir.
Starting from OS/400 V5R2 the IBM Visual Age compiler is supported on OS/400 PASE, so it is possible to build Perl natively on OS/400. The
easier way, however, is to compile in AIX, as just described.
If you don't want to install the compiled Perl in AIX into /QOpenSys (for packaging it before copying it to PASE), you can use a Configure
parameter: -Dinstallprefix=/tmp/QOpenSys/perl. This will cause the "make install" to install everything into that directory, while the
installed files still think they are (will be) in /QOpenSys/perl.
If building natively on PASE, please do the build under the /QOpenSys directory, since Perl is happier when built on a case sensitive
filesystem.
Installing Perl in OS/400 PASE
If you are compiling on AIX, simply do a "make install" on the AIX box. Once the install finishes, tar up the /QOpenSys/perl directory.
Transfer the tarball to the OS/400 using FTP with the following commands:
> binary
> site namefmt 1
> put perl.tar /QOpenSys
Once you have it on, simply bring up a PASE shell and extract the tarball.
If you are compiling in PASE, then "make install" is the only thing you will need to do.
The default path for perl binary is /QOpenSys/perl/bin/perl. You'll want to symlink /QOpenSys/usr/bin/perl to this file so you don't have
to modify your path.
Using Perl in OS/400 PASE
Perl in PASE may be used in the same manner as you would use Perl on AIX.
Scripts starting with #!/usr/bin/perl should work if you have /QOpenSys/usr/bin/perl symlinked to your perl binary. This will not work if
you've done a setuid/setgid or have environment variable PASE_EXEC_QOPENSYS="N". If you have V5R1, you'll need to get the latest PTFs to
have this feature. Scripts starting with #!/QOpenSys/perl/bin/perl should always work.
Known Problems
When compiling in PASE, there is no "oslevel" command. Therefore, you may want to create a script called "oslevel" that echoes the level
of AIX that your version of PASE runtime supports. If you're unsure, consult your documentation or use "4.3.3.0".
If you have test cases that fail, check for the existence of spool files. The test case may be trying to use a syscall that is not
implemented in PASE. To avoid the SIGILL, try setting the PASE_SYSCALL_NOSIGILL environment variable or have a handler for the SIGILL. If
you can compile programs for PASE, run the config script and edit config.sh when it gives you the option. If you want to remove fchdir(),
which isn't implement in V5R1, simply change the line that says:
d_fchdir='define'
to
d_fchdir='undef'
and then compile Perl. The places where fchdir() is used have alternatives for systems that do not have fchdir() available.
Perl on ILE
There exists a port of Perl to the ILE environment. This port, however, is based quite an old release of Perl, Perl 5.00502 (August 1998).
(As of July 2002 the latest release of Perl is 5.8.0, and even 5.6.1 has been out since April 2001.) If you need to run Perl on ILE,
though, you may need this older port: <http://www.cpan.org/ports/#os400> Note that any Perl release later than 5.00502 has not been ported
to ILE.
If you need to use Perl in the ILE environment, you may want to consider using Qp2RunPase() to call the PASE version of Perl.
AUTHORS
Jarkko Hietaniemi <jhi@iki.fi> Bryan Logan <bryanlog@us.ibm.com> David Larson <larson1@us.ibm.com>
perl v5.18.2 2013-11-04 PERLOS400(1)