----- Original Message ----- From: "John W. Krahn" <[EMAIL PROTECTED]> To: "Perl Beginners" <beginners@perl.org> Subject: Re: Setting a Hash Using the Contents of a File Date: Mon, 21 Feb 2005 12:39:25 -0800
> Finally, a bite - but I'm done a'ready. > Jon Mathews wrote: > > Not sure how else to word this. Basically, I have a util which reads a > > config file > > That is one "wheel" that has been invented many times before: > > http://search.cpan.org/author/MWS/CONFIG-V0.99.11/Hash.pm > http://search.cpan.org/author/AVAJADI/Config-Abstract-0.12/Abstract.pm > http://search.cpan.org/author/KANE/Config-Auto-0.11/lib/Config/Auto.pm > http://search.cpan.org/author/JONBJ/Config-Easy-0.2/lib/Config/Easy.pm > http://search.cpan.org/author/NWIGER/Config-Fast-1.04/Fast.pm > http://search.cpan.org/author/AHICOX/Config-Framework-2.5/Framework.pod > http://search.cpan.org/author/BTROTT/Config-FreeForm-0.01/FreeForm.pm > http://search.cpan.org/author/OESTERHOL/Config-Frontend-0.18/lib/Config/Frontend.pm > http://search.cpan.org/author/PTANDLER/Bundle-PBib-2.08/lib/Config/General.pm > http://search.cpan.org/author/WADG/Config-IniFiles-2.38/IniFiles.pm > http://search.cpan.org/author/JENDA/Config-IniHash-2.7/IniHash.pm > http://search.cpan.org/author/DRTECH/Config-Loader-0.01/lib/Config/Loader.pm > http://search.cpan.org/author/RUSTYP/Config-Magic-0.76/lib/Config/Magic.pm > http://search.cpan.org/author/SAPER/Config-Natural-0.99/lib/Config/Natural.pm > http://search.cpan.org/author/ROTH/Config-Objective-0.9.1/lib/Config/Objective.pm > http://search.cpan.org/author/DANBERR/Config-Record-1.0.5/lib/Config/Record.pod > http://search.cpan.org/author/SHERZODR/Config-Simple-4.58/Simple.pm > http://search.cpan.org/author/ADAMK/Config-Tiny-2.00/lib/Config/Tiny.pm > http://search.cpan.org/author/ATRICKETT/Config-Trivial-0.40/lib/Config/Trivial.pm > http://search.cpan.org/author/ROODE/Config-Vars-0.01/Vars.pm > etc. > etc... > Thanks - some of these are close to drop-in solutions which I will consider in the future where applicable (like code that I actually run). However, they add complexity to the config file which will be created/maintained by lots of rather low-level users. I would rather they not have to know names of variables, keys, formats, etc. any more than absolutely necessary. They seem to like the last working method okay - and it is working out better than I expected. Since I actually need to read multiple hashes from the config file, I saw no example which was an amalgam of having the minimal amount of the structure in the config file and the rest in the code - to keep the config file simple. > > > to set metadata which is kept finally in a HOH. I want to > > support another form of the config file, though, which may be less > > flexible, but is easier to read. Here is some example code which shows > > my progression of thinking in 4 sections - the last of which is the one > > that shows what I want to do: > > > > #!/usr/bin/perl -w > > use strict ; > > { # Out of the book method. > > my %Hash = () ; > > print "Using values\n" ; > > %Hash = ( FileName => '^.ssh$', IsDir => 1, > > Desc => "Secure Shell directory" ) ; > > foreach ( keys %Hash ) { > > print "Key = $_\n" ; > > print "\$Hash{$_}=" . $Hash{$_} . "\n" ; > > } ; > > } > > Just curious, which book did you get this method from? > Advanced Perl Programming - O'Reilly - first edition - p. 10. > > > { # From scalar delimited by commas - like what is in the cfg > > file used below. > > my %Hash = () ; > > print "\nUsing variable\n" ; > > my $HashInit = '( FileName,^.ssh$,IsDir,1,Desc,Secure Shell directory )' ; > > ( $HashInit = $HashInit ) =~ s/^\s*\(\s*(.*)\s*\)\s*$/$1/ ; > > Why are you assigning the contents of $HashInit to $HashInit? It would be > simpler to write that as: > > $HashInit =~ s/^\s*\(\s*(.*)\s*\)\s*$/$1/ ; > Good catch, an oversight when making this from first concepts where I had something more like: ( $Var = $DifferentVar ) =~ s/^\s*\(\s*(.*)\s*\)\s*$/$1/ ; > > > my @HashInit = split (/,/,$HashInit ) ; > > %Hash = @HashInit ; > > You could skip the array and assign the output from split() directly to %Hash. > True, I used it to bring out parallelism between the last three methods. > > > foreach ( keys %Hash ) { > > print "Key = $_\n" ; > > print "\$Hash{$_}=" . $Hash{$_} . "\n" ; > > } ; > > } > > > > { # From file, delimited by commas, can't have whitespace, > > # didn't get "=>" to work. > > my %Hash = () ; > > print "\nUsing config file\n" ; > > my $HashInit = undef ; > > open ( CfgFile, "CfgFile.txt" ) ; > > You should *always* verify that the file opened correctly before trying to > read from the filehandle. > Yes, but for simplicity, I left that sort of thing off with the other 700+ lines and tried to beginner-ize by making a small working example. Perhaps on this forum I should more strictify my examples - seems a good policy. Especially when I started off so good by using "-w" and "use strict". > > > chomp ( my @Lines=<CfgFile> ) ; > > close CfgFile ; > > foreach ( @Lines ) { > > # Discard comment or blank lines#. > > next if ( /^\s*\#/ || /^\s*$/ ) ; > > # Concatenate all the contents for this hash together. > > $HashInit = $HashInit . $_ ; > > # Look for the end of the hash definition-a parenthesis at the end > > # of the line. > > if ( /\)\s*$/ ) { > > # Throw away the parens and any padding whitespace - they > > # are just for looks and to find the end of the hash def. > > ( $HashInit = $HashInit ) =~ s/^\s*\(\s*(.*)\s*\)\s*$/$1/ ; > > # Stuff comma-delimited list in hash. > > %Hash = split (/,/,$HashInit ) ; > > $HashInit = undef ; > > } ; > > } ; > > foreach ( keys %Hash ) { > > print "Key = $_\n" ; > > print "\$Hash{$_}=" . $Hash{$_} . "\n" ; > > } ; > > } > > > > { # This one doesn't work, of course. > > [snip code] > > > Contents of CfgFile.txt would be like: > > ( Name,^\.ssh$, > > IsDir,1, > > Desc,Secure Shell directory ) > > > > Contents of a config file I would like to use would be like these examples: > > # This is the sort of thing I want to use, has commas in > > expressions, whitespace, etc. > > ( Name => '^\.ssh$', > > IsDir => 1, > > Desc => "Secure Shell directory" ) > > > > ( > > SubDir => '^\.ssh$', > > Desc => "Secure Shell stuff" > > ) > > > > ( Name => '^\.log$', > > SubDir => '^log$', > > IsDir => 0, > > MDays => > 31, > > Desc => "Log files in log directories not modified in the last 31 days" > > ) > > > > ( Name => '^:0,[0-9]+\.dat$', > > SubDir => '^data$', > > IsDir => 0, > > ADays => > 10, > > Desc => "Data files in data directories not accessed in the last 10 > > days" ) > > > > Any ideas appreciated. > > You could use the Data::Dumper module to get files like that. > > perldoc Data::Dumper > > > > John > -- use Perl; > program > fulfillment > > -- To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > <http://learn.perl.org/> <http://learn.perl.org/first-response> -- _______________________________________________ Find what you are looking for with the Lycos Yellow Pages http://r.lycos.com/r/yp_emailfooter/http://yellowpages.lycos.com/default.asp?SRC=lycos10 -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>
