[11459] in Perl-Users-Digest
Perl-Users Digest, Issue: 5058 Volume: 8
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Thu Mar 4 20:07:33 1999
Date: Thu, 4 Mar 99 17:00:23 -0800
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Thu, 4 Mar 1999 Volume: 8 Number: 5058
Today's topics:
Re: <STDIN> Question (Larry Rosler)
Re: <STDIN> Question <emschwar@mail.uccs.edu>
Re: <STDIN> Question <uri@ibnets.com>
Re: <STDIN> Question (Sean McAfee)
Re: <STDIN> Question <emschwar@mail.uccs.edu>
Case of missing cc and re -- a repost asking the correc <m-fuerst@cecer.army.mil>
Re: Cross Platform DBMs <jeromeo@atrieva.com>
Special: Digest Administrivia (Last modified: 12 Dec 98 (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Thu, 4 Mar 1999 15:38:35 -0800
From: lr@hpl.hp.com (Larry Rosler)
Subject: Re: <STDIN> Question
Message-Id: <MPG.1148b959b5fb75c29896e1@nntp.hpl.hp.com>
In article <_vDD2.147$I51.15386@news.shore.net> on Thu, 04 Mar 1999
22:08:58 GMT, Scratchie <upsetter@ziplink.net> says...
...
> I have a program that, in a certain situation, reads a file from STDIN (in
> other words, it's called as 'myscript < myfile').
>
> Is there a way, once STDIN has been read and stored in an array, to
> "reset" STDIN so I can interact with the user? (a la 'chomp ($response =
> <STDIN>);').
Trivial on Windows/DOS, because I know the name of the 'console'.
#!/usr/local/bin/perl -w
use strict;
print while <STDIN>; # prints the redirected input file
open STDIN, 'CON' or die "Couldn't open STDIN. $!\n";
print while <STDIN>; # echoes the terminal
__END__
I'm having trouble on Unix, though, because there are many pseudo-files
named "/dev/tty...". This C program:
#include <stdio.h>
#include <unistd.h>
main()
{
char *tty = ttyname(0);
printf("|%s|\n", tty);
}
prints the name of the attached STDIN tty pseudo-file, *unless* STDIN
has been redirected, in which case the function returns the null string.
Any other thoughts???
--
Larry Rosler
Hewlett-Packard Company
http://www.hpl.hp.com/personal/Larry_Rosler/
lr@hpl.hp.com
------------------------------
Date: 04 Mar 1999 16:56:59 -0700
From: Eric The Read <emschwar@mail.uccs.edu>
Subject: Re: <STDIN> Question
Message-Id: <xkfww0whkqc.fsf@valdemar.col.hp.com>
Scratchie <upsetter@ziplink.net> writes:
> I have a program that, in a certain situation, reads a file from STDIN (in
> other words, it's called as 'myscript < myfile').
>
> Is there a way, once STDIN has been read and stored in an array, to
> "reset" STDIN so I can interact with the user? (a la 'chomp ($response =
> <STDIN>);').
Nope. By redirecting, myfile *is* stdin. If you want to interact with
the user, provide a command-line argument, like 'myscript -f myfile', and
then you can use STDIN to get responses from the user to your heart's
content.
-=Eric
------------------------------
Date: 04 Mar 1999 19:12:07 -0500
From: Uri Guttman <uri@ibnets.com>
To: lr@hpl.hp.com (Larry Rosler)
Subject: Re: <STDIN> Question
Message-Id: <39pv6ohk14.fsf@ibnets.com>
>>>>> "LR" == Larry Rosler <lr@hpl.hp.com> writes:
LR> In article <_vDD2.147$I51.15386@news.shore.net> on Thu, 04 Mar 1999
LR> 22:08:58 GMT, Scratchie <upsetter@ziplink.net> says...
LR> ...
>> I have a program that, in a certain situation, reads a file from STDIN (in
>> other words, it's called as 'myscript < myfile').
>>
>> Is there a way, once STDIN has been read and stored in an array, to
>> "reset" STDIN so I can interact with the user? (a la 'chomp ($response =
>> <STDIN>);').
LR> I'm having trouble on Unix, though, because there are many pseudo-files
LR> named "/dev/tty...". This C program:
on (most) unix the device /dev/tty should always be the terminal you are
running on.
LR> Any other thoughts???
but perl is smarter than you are. this seems to work just fine:
perl -e '@a=<>; print @a; open( STDIN, q(-) ); $l=<>; print "[$l]\n"'
uri
--
Uri Guttman Hacking Perl for Ironbridge Networks
uri@sysarch.com uri@ironbridgenetworks.com
------------------------------
Date: Fri, 05 Mar 1999 00:22:35 GMT
From: mcafee@waits.facilities.med.umich.edu (Sean McAfee)
Subject: Re: <STDIN> Question
Message-Id: <ftFD2.10070$Ge3.39450846@news.itd.umich.edu>
In article <_vDD2.147$I51.15386@news.shore.net>,
Scratchie <upsetter@ziplink.net> wrote:
>I have a program that, in a certain situation, reads a file from STDIN (in
>other words, it's called as 'myscript < myfile').
>Is there a way, once STDIN has been read and stored in an array, to
>"reset" STDIN so I can interact with the user? (a la 'chomp ($response =
><STDIN>);').
I don't think you can "reset" STDIN, but if you're on a Unix system you can
reopen it using /dev/tty:
while (<STDIN>) { print }
open(STDIN, "< /dev/tty");
print "Did you like what you saw? ";
chomp($reply = <STDIN>);
--
Sean McAfee mcafee@umich.edu
print eval eval eval eval eval eval eval eval eval eval eval eval eval eval
q!q@q#q$q%q^q&q*q-q=q+q|q~q:q? Just Another Perl Hacker ?:~|+=-*&^%$#@!
------------------------------
Date: 04 Mar 1999 17:57:50 -0700
From: Eric The Read <emschwar@mail.uccs.edu>
Subject: Re: <STDIN> Question
Message-Id: <xkfemn4hhwx.fsf@valdemar.col.hp.com>
mcafee@waits.facilities.med.umich.edu (Sean McAfee) writes:
> I don't think you can "reset" STDIN, but if you're on a Unix system you can
> reopen it using /dev/tty:
>
> while (<STDIN>) { print }
> open(STDIN, "< /dev/tty");
> print "Did you like what you saw? ";
> chomp($reply = <STDIN>);
Note that Bad Things(tm)-- well, the Wrong Thing, anyway-- will happen
if this code is executed in the middle of a program that's being run
without a tty associated with it. cron is only one example, but I'd
imagine just about anything that works on the same principle would do the
same.
-=Eric
------------------------------
Date: Thu, 04 Mar 1999 16:58:01 -0600
From: Michael Fuerst <m-fuerst@cecer.army.mil>
Subject: Case of missing cc and re -- a repost asking the correct question.
Message-Id: <36DF0FF8.272D31D3@cecer.army.mil>
*******Question 1
Can someone show me (a new PERL convert)
HOW to RECOGNIZE a a string of comma separated words
with intervening
spaces, tabs and new lines, form w/i a longer string
(eg a function call or variable declaration)
and put the resulting words into an array?
My interest is learning the intracies of regular expressions.
My attempt below doesn't quite work--and would
like to know where I went wrong.
I obviously am overlooking one or two important principles.
Thanks for any insights you can give me.
# A word must start with a letter or _ and may be surrrounded by
optional white space
$word = '\s*[a-zA-Z_]\w*\s*';
# A word list can be a comma separated list of words or just a word.
# The ?:'s are intended to group w/o filling the array
$wordlist = "(?:(?:(?:($word),)+($word))|($word))";
# The following puts a zero length string in each of
# $oo[0] and $oo[1], and aa into $oo[2]
# I had hoped just to see aa in $oo[0]
@oo = 'aa' =~ m"$wordlist"smg;
print @oo[0] . " " . length(@oo[0]) . "\n";
print @oo[1] . " " . length(@oo[1]) . "\n";
print @oo[2] . " " . length(@oo[2]) . "\n";
# The following puts aa and bb string in each of
# $pp[0] and $pp[1] (as I expected) ,
# and a zero length string into $pp[2] (I expected
# pp to have only 2 elements!!)
@pp = 'aa, bb' =~ m"$wordlist"smg;
print @pp[0] . " " . length(@pp[0]) . "\n";
print @pp[1] . " " . length(@pp[1]) . "\n";
print @pp[2] . " " . length(@pp[2]) . "\n";
# The following puts bb into $qq[0],
# a space and cc into $qq[1] (both as expected
# and a zero length string into $qq[2]
# (I expected aa, bb and space cc to be in the the 3 elements of qq
@qq = 'aa,bb, cc' =~ m"$wordlist"smg;
print @qq[0] . " " . length(@qq[0]) . "\n";
print @qq[1] . " " . length(@qq[1]) . "\n";
print @qq[2] . " " . length(@qq[2]) . "\n";
--
(If this message was posted to a newsgroup,
please reply to both me and the newsgroup.)
Michael Fuerst
Work: Construction Engineering Research Lab
Box 9005
Champaign IL 62826 217-373-7273
Home: 802 N Broadway
Urbana IL 61801 217-239-5844
------------------------------
Date: Thu, 04 Mar 1999 16:05:35 -0800
From: Jerome O'Neil <jeromeo@atrieva.com>
To: Simeon McAleer <mcaleer@jlab.org>
Subject: Re: Cross Platform DBMs
Message-Id: <36DF1FCF.383F572E@atrieva.com>
Debug::Psychic prognosticates that you are using Any_DBM. I looks like
it is using sdbm on the Sun and some other dbm (gdmb) on the linux box.
You need to ensure that they are using the same library.
Even then, I don't think dbm files are portable between platforms. I
have problems moving gdbm files from Solaris to SCO and back.
Good Luck!
Simeon McAleer wrote:
>
> I am trying to use a internal PERL DBM database to record the output of
> some programs I am running. On Sun machines perl database files are
> created in pairs with the file extensions .dir and .pag. On Linux there
> is only one file created with a .db extension. The files created on one
> platform can not be accessed by PERL on the other platform. Does any one
> know how to get around this problem? Thanks in advance.
--
Jerome O'Neil, Operations and Information Services
Atrieva Corporation, 600 University St., Ste. 911, Seattle, WA 98101
jeromeo@atrieva.com - Voice:206/749-2947
The Atrieva Service: Safe and Easy Online Backup http://www.atrieva.com
------------------------------
Date: 12 Dec 98 21:33:47 GMT (Last modified)
From: Perl-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Special: Digest Administrivia (Last modified: 12 Dec 98)
Message-Id: <null>
Administrivia:
Well, after 6 months, here's the answer to the quiz: what do we do about
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]From: Russ Allbery <rra@stanford.edu>
]Date: 21 Sep 1998 19:53:43 -0700
]Subject: comp.lang.perl.moderated available via e-mail
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------------------------------
End of Perl-Users Digest V8 Issue 5058
**************************************
