Perl next if @array (exclude a list of values)


 
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# 1  
Old 04-27-2016
Perl next if @array (exclude a list of values)

I'm trying to exlude a list of values with perl to process while reading in a file. Is there a way to use the
Code:
next if

with a list?

Example:

Code:
@array = qw(val1 val2 val3 val6);

while (<>) {
 next if $_ =~ @array;	# values I don't want to process here
 print;			# process the rest here
}

Thanks in advance!
# 2  
Old 04-27-2016
Any time you want to quickly check if something is in a list, use a hash...
Code:
%hash=(val1 => 1, val2 => 1,  val3 => 1,  val6 => 1, ); # hash with unwanted items as keys and values that evaluate as true
while (<>) {
 next if $hash{$_};	# values you don't want to process are skipped here
 print;			# process the rest here
}

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# 3  
Old 04-28-2016
Using grep
Code:
@arry = qw (val1 val2 val3 val3);
while (<>){
  $line=$_;
  next if (grep(/$line/,@arry));
  print ;
}

# 4  
Old 04-28-2016
Hi Pravin,

That will work however, while it will use less memory than a hash, it will use a lot more cycles. you are grepping through the (potentially large array) for every line of the file.

Where you have a static list you wish check against a hash is the preferred solution as you take advantage of the hashing to very quickly return the value.
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# 5  
Old 05-20-2016
Will this work with a range?

Code:
%hash=(val1 => 1, val2 => 1,  val3 => 1,  val6 => 1, ); # hash with unwanted items as keys and values that evaluate as true
while (<>) {
 print if (/$hash{$_}/ .. /END/);	
}

# 6  
Old 05-20-2016
Quote:
Originally Posted by timj123
Will this work with a range?

Code:
%hash=(val1 => 1, val2 => 1,  val3 => 1,  val6 => 1, ); # hash with unwanted items as keys and values that evaluate as true
while (<>) {
 print if (/$hash{$_}/ .. /END/);	
}

I am afraid it will not work, regardless of what you are trying to do.
$_ in the while loop will have a new line with it and it will never match any of the %hash keys.
$hash{$_} will evaluate to a 1 if exist and to undef if it doesn't, thus /1/ .. /END/ or /undef/ .. /END/, which makes a moot condition.

What is it that you are trying to do? The latest seems off from your original query.
Could you post input and desired output examples?
# 7  
Old 05-20-2016
Yes and Thanks.
I'm trying to remove sections of a file based on an input of values.

Here is a sample of the file I'm trying to "edit"
Code:
section /total/SMS-MT-FSM-DEL-REP045
country: IN
1280363645.979354_PFS_1_1887728354
begin:03
final:56
END

section /total/SMS-MO-FSM001
country: IR
1280105721.484103_PFM_1_1187616097
final:23
END

section /total/SMS-MT-FSM-DEL-REP095
country: IN
1280363645.729309_PFS_1_1084296392
final:43
END

section /total/SMS-MO-FSM001
country: IR
1280105721.484103_PFM_1_1187616097
final:23
END

section /total/SMS-MO-FSM095
country: MO
1280105721.461090_PFM_1_882824215
begin:12
final:89
END

With a list given to me as:
Code:
REP045
REP095

I want to remove the sections of the file related to a list given above.

Desired output:
Code:
section /total/SMS-MO-FSM001
country: IR
1280105721.484103_PFM_1_1187616097
final:23
END

section /total/SMS-MO-FSM095
country: MO
1280105721.461090_PFM_1_882824215
begin:12
final:89
END

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