Tutorial Addendum on Perl - Allotment A - Alive with DBM Files

Run this program, and book concordance again. You will see that the new access is amid

    

at the end of the file:

    

 

    
>DbmUpdate.pl dictionary

    
>dbmprint.pl dictionary

    
bible = bible

    
computer = ordinateur

    
good = bon

    
milk = lait

    
price = prix

    
ten = dix

    
cloth = vetement

    

The fourth program, DbmLookup.pl, looks up a chat from the dictionary:

    

 

    
#- DbmLookup.pl

    
#- Absorb (c) 1996 by Dr.  Yang

    
#

    
   ($name, $key) = @ARGV;

    
   die "Missing DBM name.

" unless $name;

    
   die "Missing key.

" unless $key;

    
   dbmopen(%map,$name,0666);

    
   if ($map{$key}) {

    
      print($key,   =  , $map{$key}, "

");

    
   } abroad {

    
      print($key, " = (not defined)

");

    
   }

    
   dbmclose(%map);

    
   exit;

    

Try it with a brace of words:

    

 

    
>dbmlookup.pl concordance apple

    
apple = (not defined)

    
>dbmlookup.pl concordance milk

    
milk = lait

    

DBM Archetype - book Table

    

This DBM archetype will appearance you how to administer a table with assorted columns. In the afterward

    

Perl program, BookInsert.pl, I abutting all columns into a individual cord with "
" as

    

the delimiter, and stored it into the hash:

    

 

    
#- DbmInsert.pl

    
#- Absorb (c) 1996 by Dr.  Yang

    
#

    
   ($name) = @ARGV;

    
   die "Missing DBM name.

" unless $name;

    
   dbmopen(%map,$name,0666);

    
   $id = &lastKey();

    
   $id++;

    
   $key = $id;

    
   $title = "Programming Perl";

    
   $author = "Larry Wall";

    
   $date = "Jan 1991";

    
   $isbn = "0937175641";

    
   $edition = "1";

    
   $val = join("	",$title,$author,$date,$edition,$isbn);

    
   $map{$key} = $val;

    
   $id++;

    
   $key = $id;

    
   $title = "Learning Perl";

    
   $author = " Randal L. Schwartz";

    
   $date = "Nov 1993";

    
   $isbn = "1565920422";

    
   $edition = "3";

    
   $val = join("	",$title,$author,$date,$edition,$isbn);

    
   $map{$key} = $val;

    
   dbmclose(%map);

    
   exit;

    
sub lastKey {

    
   bounded $max = 0;

    
   bounded $key, $val;

    
   while (($key,$val)=each(%map)) {

    
      $max = $key if ($key>$max);

    
   }

    
   acknowledgment $max;   

    
}

    

To accompany aback alone columns from the hash, I acclimated the breach action as apparent

    

in the afterward program, BookPrint.pl

    

 

    
#- BookPrint.pl

    
#- Absorb (c) 1996 by Dr.  Yang

    
#

    
   ($name) = @ARGV;

    
   die "Missing DBM name.

" unless $name;

    
   dbmopen(%map,$name,0666);

    
   $rec = 0;

    
   while (($key,$val)=each(%map)) {

    
      $rec++;

    
      $id = $key;

    
      ($title,$author,$date,$edition,$isbn) = split("	",$val);

    
      book "

Record: $rec

";

    
      book "        id = $id

";

    
      book "    columnist = $author

";

    
      book "      date = $date

";

    
      book "   copy = $edition

";

    
      book "      isbn = $isbn

";

    
   }

    
   dbmclose(%map);

    
   exit;

    

Here is the achievement of active these programs together:

    

 

    
>bookinsert.pl bookbase

    
>bookprint.pl bookbase

    
Record: 1

    
        id = 1

    
    columnist = Larry Wall

    
      date = Jan 1991

    
   copy = 1

    
      isbn = 0937175641

    
Record: 2

    
        id = 2

    
    columnist =  Randal L. Schwartz

    
      date = Nov 1993

    
   copy = 1

    
      isbn = 1565920422