Thanks a lot. Your guess was right. The second part was what I needed. I am
still not a little confused about the first, though. They do not teach
this in the institution where I study. :)
Could you give a good reference to this things, IPC, pipes, fifo, sockets,
etc? I could not make much headway, from what I read in the man pages, and
perldoc.
Thanks lot,
-tir
On Fri, 12 Apr 2002, Nikola Janceski wrote:
> no... Open2 opens 2 filehandles for a command.
>
> this:
> open2(*READ, *ZIPIT, "/apps/bin/zip $FORM{'zipfile'} -@ 2>&1");
> opens a filehandle READ that the command reads from AND
> opens a filehandle ZIPIT that the command outputs from
>
> at a command prompt this is what it means:
>
> cat | /apps/bin/zip somefile.zip -@ 2>&1 | more;
> ^ ^
> READ ZIPIT
>
> That's where the file handles are.
> Don't know what your command is for or what exactly you are trying to pass
> but here is my guess:
>
> You really just want to pipe the open to output only:
>
> open(OUTFILE, ">output.file") || die "Can't open for write: $!";
> open(COMMAND, "bunzip2 -c $ParseFile | discretise $delta $BOD $EOD |") or
> die "Cann't execute: $!";
> while(<COMMAND>){
> print OUTPUT;
> }
> close COMMAND;
> close OUTFILE;
>
>
>
> > -----Original Message-----
> > From: Tirthankar C. Patnaik [mailto:[EMAIL PROTECTED]]
> > Sent: Friday, April 12, 2002 2:00 PM
> > To: Nikola Janceski
> > Cc: [EMAIL PROTECTED]
> > Subject: RE: Input | Program | Output : help
> >
> >
> >
> >
> > > did you try reading the docs? You didn't even try to use my example.
> >
> > I did try. I could not understand your example. Let me explain:
> >
> >
> > > > > open2(*READ, *ZIPIT, "/apps/bin/zip $FORM{'zipfile'} -@ 2>&1");
> > > > > READ is the input pipe
> > > > > ZIPIT is the output pipe
> >
> > Here, are *READ, and *ZIPIT, already open, using open statements?
> >
> > e.g.,
> > open(*READ,"<$ParseFile") || die "$!";
> > open(*ZIPIT,"| discretise 15 35700 55800 > ${OutFile}")
> > || die "$!";
> >
> > open2(\*READ,\*ZIPIT);
> >
> > I tried this, and it didn't work. I am confused. Sorry, but please
> > explain. A working complete example would be great.
> >
> > TIA,
> >
> > -tir
> >
> >
> >
> > >
> > > perldoc IPC::Open2
> > >
> > > > -----Original Message-----
> > > > From: Tirthankar C. Patnaik [mailto:[EMAIL PROTECTED]]
> > > > Sent: Friday, April 12, 2002 1:52 PM
> > > > To: Nikola Janceski
> > > > Cc: [EMAIL PROTECTED]
> > > > Subject: RE: Input | Program | Output : help
> > > >
> > > >
> > > >
> > > > I'm afraid I couldn't succeed in using the IPC::Open2 module.
> > > > Where am I
> > > > going wrong?
> > > >
> > > > # }
> > > > my($IN,$OUT);
> > > > open(OUT,"| discretise ${delta} ${BOD} ${EOD}") || die
> > > > "Sorry out: $!";
> > > >
> > > > if($suffix eq ".par"){
> > > > open(IN,"<$ParseFile") || die "Sorry: $!";
> > > > open2('IN','OUT');
> > > > }
> > > >
> > > > Could you please explain the code, in more detail?
> > > >
> > > > TIA,
> > > > -tir
> > > >
> > > >
> > > > }
> > > >
> > > >
> > > > On Fri, 12 Apr 2002, Nikola Janceski wrote:
> > > >
> > > > > You might want to look at IPC::Open2
> > > > >
> > > > > You can open a system command with an INPUT pipe and
> > OUTPUT pipe.
> > > > >
> > > > > Here is how I used it.
> > > > >
> > > > > open2(*READ, *ZIPIT, "/apps/bin/zip $FORM{'zipfile'} -@ 2>&1");
> > > > > READ is the input pipe
> > > > > ZIPIT is the output pipe
> > > > >
> > > > > Perl Gurus, Yeah I should have used the ZIP module.. I am
> > > > too lazy to change
> > > > > it now.
> > > > >
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Tirthankar C. Patnaik [mailto:[EMAIL PROTECTED]]
> > > > > > Sent: Friday, April 12, 2002 1:04 PM
> > > > > > To: [EMAIL PROTECTED]
> > > > > > Subject: Input | Program | Output : help
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Folks,
> > > > > > Consider this code snippet:
> > > > > >
> > > > > > Here $ParseFile is a plain-text file, which could be gzipped,
> > > > > > bzipped, or
> > > > > > not compressed at all. I'd like my program to determine
> > > > this, open the
> > > > > > file, and cat it to another program called discretise.
> > > > > >
> > > > > > In the code below,
> > > > > >
> > > > > > my(@PARSELIST) = @ARGV; # This would be the
> > .par files.
> > > > > > my($ParseFile);
> > > > > > for $ParseFile (@PARSELIST){
> > > > > > chomp $ParseFile;
> > > > > > my($date,$name,$suffix) = &FileTest($ParseFile); # uses
> > > > > > File::Basename
> > > > > > if($suffix eq ".bz2"){
> > > > > > system("bunzip2 -c $ParseFile | discretise $delta
> > > > > > $BOD $EOD > ${OUTFILE}");
> > > > > > }elsif($suffix eq ".gz"){
> > > > > > system("gunzip -c $ParseFile | discretise $delta $BOD
> > > > > > $EOD > ${OUTFILE}");
> > > > > > }elsif($suffix eq ".par"){
> > > > > > system("cat $ParseFile | discretise $delta $BOD $EOD
> > > > > > > ${OUTFILE}");
> > > > > > }
> > > > > >
> > > > > >
> > > > > > As you can see, I've got three system commands to run on
> > > > $ParseFile,
> > > > > > depending on it's extn (.par/.gz/.bz2).
> > > > > >
> > > > > > I don't know how I should ask this, but can I
> > > > > >
> > > > > > 1. open $ParseFile and assign a filehandle to it
> > (IN), say.
> > > > > > 2. open $Outfile and assign a filehandle to it (OUT),
> > > > > > 3. determine the extension of the input file,
> > > > > >
> > > > > > And this is the important part:
> > > > > > 4. Depending on the extension, cat, gunzip -c, or bunzip
> > > > > > -c the input
> > > > > > file to the output file, using the _filehandle_,
> > > > > > without a system
> > > > > > command.
> > > > > >
> > > > > > Is this possible in Perl, if so how to do it? And is it
> > > > > > necessary?
> > > > > >
> > > > > > For instance, I could have,
> > > > > >
> > > > > > if($suffix eq ".bz2"){
> > > > > > open(IN, "bunzip2 -c $ParseFile|")
> > > > > > ||die "Could not open $ParseFile: $!";
> > > > > > }elsif($suffix eq ".gz"){
> > > > > > open(IN, "gunzip -c $ParseFile|")
> > > > > > ||die "Could not open $ParseFile: $!";
> > > > > > }elsif($suffix eq ".par"){
> > > > > > open(IN, "<$ParseFile")
> > > > > > || die "Could not open $ParseFile: $!";
> > > > > > }
> > > > > >
> > > > > > And then I open an output file:
> > > > > >
> > > > > >
> > > > > > open(OUT, "| discretise delta BOD EOD > $OutFile") || die
> > > > > > "Sorry :$!";
> > > > > >
> > > > > > Problem: How do I channel the input from $ParseFile to the
> > > > > > OUT filehandle?
> > > > > >
> > > > > > Please explain in --verbose mode! I do not know these
> > things. :)
> > > > > >
> > > > > > -tir
> > > > > >
> > > > > >
> > > > > > TIA,
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Tirthankar, IGIDR.
> > > > > > +91-22-8400919 x275 (r), x593(o), x542(CFL).
> > > > > > http://www.igidr.ac.in/~tir
> > > > > >
> > > > > > ACKNOWLEDGE, v.t. To confess. Acknowledgement of
> > one another's
> > > > > > faults is the highest duty imposed by our love of truth.
> > > > > >
> > > > > >
> > > > > > --
> > > > > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > > > >
> > > > >
> > > > >
> > > > --------------------------------------------------------------
> > > > --------------
> > > > > --------------------
> > > > > The views and opinions expressed in this email message are
> > > > the sender's
> > > > > own, and do not necessarily represent the views and
> > > > opinions of Summit
> > > > > Systems Inc.
> > > > >
> > > > >
> > > > > --
> > > > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > Tirthankar, IGIDR.
> > > > +91-22-8400919 x275 (r), x593(o), x542(CFL).
> > > > http://www.igidr.ac.in/~tir
> > > >
> > > > SUCCESS, n. The one unpardonable sin against one's fellows. In
> > > > literature, and particularly in poetry, the elements of
> > success are
> > > > exceedingly simple, and are admirably set forth in the
> > > > following lines
> > > > by the reverend Father Gassalasca Jape, entitled, for some
> > > > mysterious
> > > > reason, "John A. Joyce."
> > > >
> > > > The bard who would prosper must carry a book,
> > > > Do his thinking in prose and wear
> > > > A crimson cravat, a far-away look
> > > > And a head of hexameter hair.
> > > > Be thin in your thought and your body'll be fat;
> > > > If you wear your hair long you needn't your hat.
> > > >
> > > >
> > > >
> > > > --
> > > > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > >
> > >
> > >
> > --------------------------------------------------------------
> > --------------
> > > --------------------
> > > The views and opinions expressed in this email message are
> > the sender's
> > > own, and do not necessarily represent the views and
> > opinions of Summit
> > > Systems Inc.
> > >
> > >
> >
> >
> > --
> > Tirthankar, IGIDR.
> > +91-22-8400919 x275 (r), x593(o), x542(CFL).
> > http://www.igidr.ac.in/~tir
> >
> > MONDAY, n. In Christian countries, the day after the baseball game.
> >
>
> ----------------------------------------------------------------------------
> --------------------
> The views and opinions expressed in this email message are the sender's
> own, and do not necessarily represent the views and opinions of Summit
> Systems Inc.
>
>
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>
--
Tirthankar, IGIDR.
+91-22-8400919 x275 (r), x593(o), x542(CFL).
http://www.igidr.ac.in/~tir
ACCORDION, n. An instrument in harmony with the sentiments of an
assassin.
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