punch_card_don has asked for the wisdom of the Perl Monks concerning the following question:

Mercurial Monks,

I'm having a little trouble with accessing an old DBM file using DBI.

We have an old DBM file:

data.pag data.dir
I simply want to see what's in it. Thought the DBI would be a good way, so:
#!/usr/bin/perl -w use strict; use warnings; use DBI; use CGI; use CGI::Carp qw(fatalsToBrowser); # start error output BEGIN { use CGI::Carp qw(carpout); carpout(*STDOUT); } print "Content-type:text/html\n\n"; my $db_name = 'data'; my $dbh = DBI->connect('dbi:DBM(RaiseError=1):'); my $sqlSelect = "SELECT * FROM $db_name"; my $sth = $dbh->prepare($sqlSelect) || die "Cannot prepare: " . $dbh-> +errstr(); $sth->execute() or die "Cannot execute: " . $sth->errstr(); while (my @data = $sth->fetchrow_array()) { print "<br>"; for my $i (0 .. $#data) { print ", $data[$i]\n"; } } $sth->finish;
But what I get is
Software error: DBD::DBM::st execute failed: Execution ERROR: No write permission to sdbm file at /bla/bla/bla/DBD/ line 422. . at /bla/bla/bla/DBI/DBD/ line 1234. [for Statement "SELECT * FROM pmb_passwords_dbm"] at lin +e 26.
For the record - both the files are chmod'd 755.

Now, I was previously getting the error "no lck file" - so I simply created an empty data.lck file and that seemed to shut that up.

What's up?


Time flies like an arrow. Fruit flies like a banana.

Replies are listed 'Best First'.
Re: Accessing old DBM file with DBI - "write permission"?
by punch_card_don (Curate) on Mar 05, 2013 at 18:38 UTC
    On the other hand, this works:
    #!/usr/bin/perl -w use warnings ; use strict ; use DB_File ; my %h; unlink "data" ; tie %h, "DB_File", "data", O_RDWR|O_CREAT, 0666, $DB_HASH or die "Cann +ot open file 'data': $!\n"; print "Content-type:text/html\n\n"; foreach my $key (sort keys %h) { print "<br>$key -> $h{$key}\n"; }
    But I get an empty result, no output. (Possible that's what's in the file, I suppose, but seems odd for a 65kb file.)

    Time flies like an arrow. Fruit flies like a banana.

      Maybe you could try to create an empty DBM file and see how big it is on your system.

        In themeantime, I found a filepath that was wrong - so now this version works perfectly. Outputs 200 lines of pairs, as sort of expected.

        So, my needs have been solved - just the mystery of the DBI version for information left.

        Time flies like an arrow. Fruit flies like a banana.