Reading and Writing Perl Config Files

%CFG = ( 'servers' => { 'SRV1' => { 'IP' => 99.32.4.0, 'user' => 'aname', 'pswd' => 'p4ssw0rd', 'status' => 'unavailable' }, 'SRV2' => { 'IP' => 129.99.10.5 'user' => 'guest', 'pswd' => 'guest' 'status' => 'unavailable' } }, 'timeout' => 60, 'log' => { 'file' => '/var/log/my_log.log', 'level' => 'warn', }, 'temp' => 'remove me' );

# Read a configuration file # The arg can be a relative or full path, or # it can be a file located somewhere in @INC. sub ReadCfg { my $file = $_[0]; our $err; { # Put config data into a separate namespace package CFG; # Process the contents of the config file my $rc = do($file); # Check for errors if ($@) { $::err = "ERROR: Failure compiling '$file' - $@"; } elsif (! defined($rc)) { $::err = "ERROR: Failure reading '$file' - $!"; } elsif (! $rc) { $::err = "ERROR: Failure processing '$file'"; } } return ($err); } # Get our configuration information if (my $err = ReadCfg('my_cfg.cfg')) { print(STDERR $err, "\n"); exit(1); }

# Add last access time $CFG::CFG{'servers'}{'SRV1'}{'last_access'} = time(); # Change server availablility $CFG::CFG{'servers'}{'SRV1'}{'status'} = 'online'; # Delete temporary data delete($CFG::CFG{'temp'}); # Open log file my $LOG; if (! open($LOG, "> $CFG::CFG{'log'}{'file'}")) { print(STDERR "ERROR: Failure opening log file: $!\n"); exit(1); }

use Data::Dumper; # Save configuration data # Use the same arg as used with ReadCfg() # so that file can be found in the %INC. sub SaveCfg { my $file = $INC{$_[0]}; my $CFG; if (! open($CFG, "> $file")) { return ("ERROR: Failure opening '$file' - $!"); } print $CFG <<_MARKER_; ##### # # My configuration file # ##### use strict; use warnings; our (%CFG); # The configuration data @{[Data::Dumper->Dump([\%CFG::CFG], ['*CFG'])]} 1; # EOF _MARKER_ close($CFG); return (undef); # Success } # Save our configuration file if (my $err = SaveCfg('my_cfg.cfg')) { print(STDERR $err, "\n"); exit(1); }

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Re: Reading and Writing Perl Config Files
by fmerges (Chaplain) on Jun 24, 2005 at 12:22 UTC

Personally I prefer to use YAML for configuration files.

Update: I think it's silly that someone give -- points for this contribution. Why? Because:

I'm not telling nothing wrong about the posting.
I think that it's a nice piece of code.

But I still recommend for config files YAML because of:

# YAML documents are very readable by humans.
# YAML interacts well with scripting languages.
# YAML uses host languages' native data structures.
# YAML has a consistent information model.
# YAML enables stream-based processing.
# YAML is expressive and extensible.
# YAML is easy to implement.

So, please, take a look at the website before giving -- points

Regards,

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Re: Reading and Writing Perl Config Files
by chanio (Priest) on Sep 04, 2005 at 03:27 UTC

jdhedden

I agree that there are several interesting aproaches to standarize config files. I also prefer the Apache config way. OTH, I should better prefer an XML way. I know.

But this is similar to what I use in my personal config files. And in this OO way, I won't feel guilty when keeping on doing so, programatically. It is error prone!

I should only point out that it is not possible to keep a special order in the variables, because of the hash nature of these config files.

But it is Ok for me and my scripts :)

{

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Wherever I lay my KNOPPIX disk, a new FREE LINUX nation could be established

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Re^2: Reading and Writing Perl Config Files

by simul (Initiate) on Feb 19, 2009 at 03:22 UTC

  use Safe;
  my $comp = new Safe;
  $comp->reval($config_file);
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[reply]
[d/l]

Re^3: Reading and Writing Perl Config Files

by Anonymous Monk on Mar 27, 2009 at 01:33 UTC

# Defines logging groups in terms of room: if device's room maatches r
+oom name or if device name is listed separately in hash, then is logg
+ed into same log:        
%Log_rooms = (
               "gallery"  => { 'BM_shutts_south_00' => 1, 'BM_shutt_no
+rth_00' => 1  },
               "kitchen"  => {   },
               "office"  => { },
               "living"  => { },
               "utility"  => { },
               "kurilnica"  => {},
               "lobby"  => { },
               "toilet"  => { }
              );

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use Data::Dumper;
 use Safe;
my %Log_rooms;
  my $config_file ="./Log.conf";

  if (-e $config_file) {
    print "File Exists!";
#        my $comp = new Safe;
#        my $return =$comp->reval($config_file);

        my $return = do $config_file ;

        warn "couldn't parse $config_file: $@" if $@;
        warn "couldn't do $config_file: $!"    unless defined $return;
        warn "couldn't run $config_file"       unless $return;

  } else {
        %Log_rooms = (
               "default"  => { 'BM_shutts_south_00' => 1, 'BM_shutt_no
+rth_00' => 1  }
                    );

  };  
  

print "###############################################################
+#################\n";
print Data::Dumper::Dumper(%Log_rooms);


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