perl and unix command

[lerameur]

Hello,

I am writting a perl scipt in unix and I will invoking some unix
commands in my script. If the first command takes a few minutes to
process, how do I make sure the second command do not start until the
first command is finished ?


thanks
ken

 

[Tony Curtis]

Hello,

I am writting a perl scipt in unix and I will invoking some unix
commands in my script. If the first command takes a few minutes to
process, how do I make sure the second command do not start until the
first command is finished ?

perldoc -f system

 

[lerameur]

perldoc -f system

...

/>perldoc -f system
ksh: perldoc: not found

 

[lerameur]

At 2007-09-20 09:39AM, "lerameur" wrote:




As you're using google already, you might want to use its search
function. I hear its pretty good...

google?
1,680,000 results, most of them refering to unix command in perl, in
the one I looked, have not seen any with execution time analysis
between commands.
maybe you have googled one

k

 

[Tony Curtis]

google?
1,680,000 results, most of them refering to unix command in perl, in
the one I looked, have not seen any with execution time analysis
between commands.
maybe you have googled one

You didn't ask about "execution time analysis".

Show us an example of what you're trying to do.

 

[lerameur]

You didn't ask about "execution time analysis".

Show us an example of what you're trying to do.

I though I did in the first message.
Example:

scan_log.pl
rm *.log

here are the two unix command I want to put in a perl script, The scan
log script can take 2 minutes to do the scan. I want to make sure the
rm *.log command to starts after the scan_log. I am scared that once
the scan_log.pl has been read, the script will go to the next line and
run the rm *.log command before the scan_log.pl has finished scanning.

ken

 

[Chris Davies]

/>perldoc -f system
ksh: perldoc: not found

Ask your System Administrator to install perl properly.

 

[Paul Lalli]

..

/>perldoc -f system
ksh: perldoc: not found

Your installation of Perl is broken. Have your local sysadmins fix
it.

In the meantime, perldoc on the web: http://perldoc.perl.org/functions/system.html

Paul Lalli

 

[Josef Moellers]

I though I did in the first message.
Example:



here are the two unix command I want to put in a perl script, The scan
log script can take 2 minutes to do the scan. I want to make sure the
rm *.log command to starts after the scan_log. I am scared that once
the scan_log.pl has been read, the script will go to the next line and
run the rm *.log command before the scan_log.pl has finished scanning.

The system() function will not return until the command within has
terminated. Beware that if you write something like
system("scan_log.pl&");
then "the command within" is a shell, which in turn starts scan_log.pl
without waiting for it and thus will terminate before scan_log.pl has
finished.

I.e.
system("scan_log.pl");
system("rm *.log");
will be what you want.

 

[lerameur]

The system() function will not return until the command within has
terminated. Beware that if you write something like
system("scan_log.pl&");
then "the command within" is a shell, which in turn starts scan_log.pl
without waiting for it and thus will terminate before scan_log.pl has
finished.

I.e.
system("scan_log.pl");
system("rm *.log");
will be what you want.
--
These are my personal views and not those of Fujitsu Siemens Computers!
Josef Möllers (Pinguinpfleger bei FSC)
If failure had no penalty success would not be a prize (T. Pratchett)
Company Details:http://www.fujitsu-siemens.com/imprint.html

ok thank you

k

 

[Ted Zlatanov]

l> I am writting a perl scipt in unix and I will invoking some unix
l> commands in my script. If the first command takes a few minutes to
l> process, how do I make sure the second command do not start until the
l> first command is finished ?

This is what will happen by default, unless the first command takes
special measures to detach itself and run in the background.

In Unix terms, the Perl process running the command is waiting for the
child process to exit every time it calls system(). There's more to the
picture (there are different ways to call system() for instance), but
this is the essential idea.

Ted

 

[xhoster]

..

/>perldoc -f system
ksh: perldoc: not found

Install Perl on your system.

Xho

--
-------------------- http://NewsReader.Com/ --------------------
The costs of publication of this article were defrayed in part by the
payment of page charges. This article must therefore be hereby marked
advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate
this fact.

 

[John W. Krahn]

Try "man system" - Perl docs are often installed as man pages also.

That will probably get you the system(3) man page instead of Perl's system
function (although they basicly do the same thing.)

"man perlfunc" will get you the listing for Perl's system function.

Also, check to see if your OS has a "perl-docs" or similar port|rpm|deb
or other package. Some vendors like to split Perl into multiple packages,
with separate developer and docs packages.

Kubuntu does this. I had to manually install a lot of stuff.




John

 

[lerameur]

That will probably get you the system(3) man page instead of Perl's system
function (although they basicly do the same thing.)

"man perlfunc" will get you the listing for Perl's system function.


Kubuntu does this. I had to manually install a lot of stuff.

John

I am running on sunOS 5.9 (solaris)
I do not know unix that much, so I do not know if it is a perl issue
with that specific OS.
"man perlfunc" do not work by the way
k

 

[Jim Cochrane]

google?
1,680,000 results, most of them refering to unix command in perl, in
the one I looked, have not seen any with execution time analysis
between commands.
maybe you have googled one

http://www.google.com/search?num=20...:official&hs=RW6&q=perldoc+system&btnG=Search

yields (2nd listing):

http://www.ayni.com/perldoc/perl5.8.0/pod/func/system.html

--

 

[Chris Davies]

I am running on sunOS 5.9 (solaris)
I do not know unix that much, so I do not know if it is a perl issue
with that specific OS.

It's a Solaris issue. Perl is installed into /usr/perl5/5.6.1 but only
perl itself is symlinked back into /usr/bin.

Two solutions, either of which will work:

(a) Add this statement to your ".profile" either near the top, or
immediately after the last line starting "PATH=" (if there is one):

PATH="/usr/perl5/5.6.1/bin:$PATH" export PATH

To make the change effective immediately, also type it directly at
the command prompt (just this once)

(b) Ask your System Administrator to complete Sun's botched installation
of perl, by adding its commands to /usr/bin, with a command such as
this:

cd /usr/bin && ln -s ../perl5/5.6.1/* .

This command will complain that perl already exists - don't worry
about that. Don't forget the trailing dot!!

Hope this helps,
Chris

 

[Tad McClellan]

Your installation of Perl is broken.

Or you don't have the right directories in your PATH.

 

[lerameur]

the command:
PATH="/usr/perl5/5.6.1/bin:$PATH" export PATH

works great. I have access to my perldoc pages.
thanks

ken