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implement it in elegant way

Posted on 1998-08-17
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Last Modified: 2011-09-20
Suppose I want to scan a set of files and see if each of them contains certain patterns
26 patterns altogether).
Finally print the all name of files containing pattern_a,all name of file containing file_b etc...

My stupid program is like:

.......

foreach $f (@files){
  $name=$f;
  $open(FILE,$f)|| die "cannot open";

  while (<FILE>){
     if ($_ eq /pattern_a/){
       push(@list_a,$name);
     }elsif($_ eq /pattern_b){
       push(@list_b,$name);
     }elsif($_ eq /pattern_c){
       push(@list_c,$name);
     }elsif   ....
            .....

     }elsif($_ eq /pattern_z){
       push(@list_z,$name);
     }

  }
}

  printf "files containing pattern_a: @list_a\n";
  printf "files containing pattern_b: @list_b\n";
   ......
   ......
  printf "files containing pattern_z: @list_z\n";

-----------------------------------------------------------
However, I would like to implement it like
   
         ........
       foreach $f (@files){
          $name=$f;
          $open(FILE,$f)|| die "cannot open";

          while (<FILE>){
            if (exists $pattern{$_}{
                push(@list($_),$name)  ## This is illegal!!!
            }      ## or append filename to $pattern{$_},                     ###but how to do it
         }
       }
          ........

Can anyone there enlighten me or provide more elegant code? Thank you in advance.
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Question by:tian
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3 Comments
 
LVL 84

Expert Comment

by:ozo
ID: 1203803
push @{$list{$_}},$name;

0
 
LVL 5

Accepted Solution

by:
b2pi earned 400 total points
ID: 1203804
Essentially, you want @list to be a list of lists, yes?  The following may work for you...


push(@$list{$_}, $name);

Alternatively, if you want to add the list of files containing a pattern to %patterns, you could do

push(@{$patterns{$_}}, $f);

0
 
LVL 84

Expert Comment

by:ozo
ID: 1203805
## or append filename to $pattern{$_},
$pattern{$_}.=$f;
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