Module to handle substitution in error messages?

[Henry Law]

I've googled and CPAN'd for the answer to this one but all my queries
return either zero or a zillion irrelevant entries. Maybe someone here
will know the place to look, or alternatively confirm my suspicion that
what I'm looking for doesn't exist.

In previous programming projects, using languages other than Perl, I
created a set of routines which managed the issuing of error messages.
In summary my program would issue a call (speaking Perl now)

write_error_message(203,"foo","zurb failed",$zurb_rc);

In some file stored separately the error messages would be defined, with
placeholders for the bits that would vary from one invocation to
another; perhaps (I used XML but that's not essential)

<msg id="203" severity="5">
<text>Module %s encountered a '%s' error, rc=%s</text>
<explanation>Some text to guide interpretation</explanation>
</msg>

Then on executing the call an error message would appear thus:

203-5 Module foo encountered a 'zurb failed' error, rc= ... etc

Is there a Message:arameterise module, or something?

 

[John Bokma]

I've googled and CPAN'd for the answer to this one but all my queries
return either zero or a zillion irrelevant entries. Maybe someone here
will know the place to look, or alternatively confirm my suspicion that
what I'm looking for doesn't exist.

In previous programming projects, using languages other than Perl, I
created a set of routines which managed the issuing of error messages.
In summary my program would issue a call (speaking Perl now)

write_error_message(203,"foo","zurb failed",$zurb_rc);

In some file stored separately the error messages would be defined, with
placeholders for the bits that would vary from one invocation to
another; perhaps (I used XML but that's not essential)

<msg id="203" severity="5">
<text>Module %s encountered a '%s' error, rc=%s</text>
<explanation>Some text to guide interpretation</explanation>
</msg>

Then on executing the call an error message would appear thus:

203-5 Module foo encountered a 'zurb failed' error, rc= ... etc

Is there a Message:arameterise module, or something?

Yes, it's called sprintf / printf :-D.

sub write_error_message {

my ( $id, @params ) = @_;

my ( $text, $explanation ) = look_up( $id );

printf STDERR "$text\n", @params;
printf STDERR "$explanation\n";
}


of course you could wrap in nicely up in a nice module :-D.

 

[usenet]

In previous programming projects, using languages other than Perl, I
created a set of routines which managed the issuing of error messages...

In Perl (as you suspected but were unable to find) all these routines
have been written for you. I recommend Log:ispatch (which has
extensions for XML, databases, Apache error logs, etc). This procedure
will be familar to Java programmers.

In any "serious" (non-trivial) program that I write, I use
Log:ispatch for ALL message output (including output to the terminal
- I don't use "print"). It can send you e-mails, or do all sorts of
other things based on the severity of the log message.

Here is my "skeleton" code that I use to set up several dispatchers
(but not an XML dispatcher) and log the first status message. As you
see, I create one logging object and then add several dispatcher
methods to it. These will "fire" anytime I log a message of the
appropriate severity level. For example, debug messages go to the TTY
and a logfile, but only log messages at "error" or higher would also
kick off the e-mail dispatcher.

## Create some log dispatchers

use Mail::Sendmail;
use Log:ispatch;
use Log:ispatch::Screen;
use Log:ispatch::File;
use Log:ispatch::Email::MailSendmail;

my $log; #or maybe 'our log' for some conveniences
do{ #use 'do' to lexically isolate variables
my $logdir = $cfg{'dir'}{'log'} || "/var/tmp";

my @admin_email = @{$cfg{'email'}{'admin'}} ||
sprintf('%s@%s', scalar getpwuid($<), hostname);

unshift @{$Mail::Sendmail::mailcfg{'smtp'}},
$cfg{'email'}{'smtp'} || 'localhost';

my $add_lf = sub { my %p = @_; "$p{'message'}\n"};

my $add_timestamp = sub { my %p = @_;
sprintf "%s - %s", scalar(localtime),
$p{'message'}; };

$log = Log:ispatch->new ( callbacks => $add_lf );

$log ->add( Log:ispatch::Screen ->new(
name => 'screen',
min_level => 'debug',
stderr => 0, )
);

$log ->add( Log:ispatch::File ->new(
name => 'file',
min_level => 'debug',
filename => sprintf ( "%s/%s.log",
$logdir,
$FindBin::Script ),
mode => 'append',
callbacks => $add_timestamp ),
);

$log ->add( Log:ispatch::Email::MailSendmail ->new(
name => 'email',
min_level => 'error',
to => \@admin_email,
subject => "ERROR in $PROGRAM_NAME",
from => sprintf ("SERVER<%s\@%s>",
(hostname =~ /^([^\.]*)/)[0],
'do_not_reply.com' ) ),
);
}; #do

#dispatch our very first message - print all the runtime info
$log -> debug(sprintf
"[%s] Begin %s\n\tVersion %s on %s as %s\n"
."\tConfigFile: %s\n\tKillfile(s):\n%s",
__LINE__, __FILE__,
$main::VERSION,
hostname(),
"$REAL_USER_ID ($ENV{'USER'})",
$cfg{'inifile'},
map {"\t\t$_\n"} keys %{$cfg{'killfile'}},
);

 

[Anno Siegel]

Yes, it's called sprintf / printf :-D.

sub write_error_message {

my ( $id, @params ) = @_;

my ( $text, $explanation ) = look_up( $id );

printf STDERR "$text\n", @params;
printf STDERR "$explanation\n";
}

Tiny correction: The last "printf" should rather be "print". While the
$text part appears to be a printf format, $explanation looks like it
might use "%" innocently.

Anno

 

[Brian McCauley]

In previous programming projects, using languages other than Perl, I
created a set of routines which managed the issuing of error messages.
In summary my program would issue a call (speaking Perl now)

write_error_message(203,"foo","zurb failed",$zurb_rc);

In some file stored separately the error messages would be defined, with
placeholders for the bits that would vary from one invocation to
another; perhaps (I used XML but that's not essential)

Is there a Message:arameterise module, or something?

Consider Data:hrasebook

 

[Henry Law]

In Perl (as you suspected but were unable to find) all these routines
have been written for you. I recommend Log:ispatch (which has
extensions for XML, databases, Apache error logs, etc). This procedure
will be familar to Java programmers.

<followed by lots of good code which I've snipped>

My thanks to the other posters but I think this reply of David's is what
I was looking for. Yes I could use printf, John, but there's that
little matter of the "look_up( $id )" function that you slipped in
Data:hrasebook is attractive, Brian, but I see that Log:ispatch will
also replace the logging code that I've written, which is an added bonus.

Thanks all ... usenet is still alive and well.

 

[John Bokma]

Tiny correction: The last "printf" should rather be "print". While
the $text part appears to be a printf format, $explanation looks like
it might use "%" innocently.

Ouch, you're right. Moreover:
<http://johnbokma.com/mexit/2005/06/14/>

 

[John Bokma]

My thanks to the other posters but I think this reply of David's is what
I was looking for. Yes I could use printf, John, but there's that
little matter of the "look_up( $id )" function that you slipped in

Yes, I couldn't think about a module supporting XML like in your example
(Not that I know all CPAN modules, but I check CPAN often)

Thanks all ... usenet is still alive and well.

Yup, even though there are every year rumours about its upcoming death.