how to match a paragraph by regexp?

[poolboi]

hey guys,

another regexp problem which i'm probably not good at here goes
my text file has this

 [B]/* 1 TB VTP-1 SESSION=01547 USERID STARTED 2008-05-13 09:46:11 */
I AM A GIRL
 /* 3 SESSION=01547 USERID 2008-05-13 09:46:12 */
 /* 4c COMMAND EXECUTED */ 
 /* 4c SESSION=01547 USERID=SASTST 2008-05-13 09:46:12 */
 /* 2 TB HLRi VTP-1 SESSION=01547 USERID ENDED 2008-05-13 09:47:12 */
 /* 1 TB VTP-1 SESSION=01547 USERID STARTED 2008-05-13 09:46:11 */
 I AM A BOY
 /* 3 SESSION=01547 USERID 2008-05-13 09:46:12 */
 /* 4c COMMAND EXECUTED */ 
 /* 2 TB HLRi VTP-1 SESSION=01547 USERID ENDED 2008-05-13 09:47:12 */[/B]

if u see it's like 2 paragraphs
i need to match the paragraphs as u can see each paragraph starts with "1 TB" and end with "2 TB" how can i match the one paragraph?

previously i was using this to match but this one only go through one line
how can i make it match a paragraph?

[CODE=perl]
foreach $data1 (@$data)
{
chomp ($data1);

if ($data1 =~ /1 TBHLR.+word/){ ## i replace the word with anything i wanna match
[/CODE]

[nithinpes]

Since the paragraphs are not like typical paragraphs, one way to do it is that you need to process the array containing the file-input to get an array in which each element is a paragraph and not a line.

open(IN,"data.txt")or die "failed:$!";
@file=<IN>;
foreach(@file) {
 if(/1 TB/) {$str = $_ ; next;} ## look for lines with '1 TB'
unless(/2 TB/) {
   $str.=$_  ;     ## append lines until line with '2 TB' is reached
} 
else {
$str.= $_ ; 
push @data,$str;   ## on reaching '2 TB' push the concatenated string to array
undef $str;
}  
}

#print "\n\n$_\n\n" foreach(@data);
foreach $data1 (@data)
{
##### $data1 will be a paragraph now

}

[poolboi]

great thanks!

erm just some clarification

the opertor ".=" is an overload operator right? meaning to say it appends yr previous data

and what's the use of putting undef $str??

correct me if i'm wrong
:)

[poolboi]

Since the paragraphs are not like typical paragraphs, one way to do it is that you need to process the array containing the file-input to get an array in which each element is a paragraph and not a line.

open(IN,"data.txt")or die "failed:$!";
@file=<IN>;
foreach(@file) {
 if(/1 TB/) {$str = $_ ; next;} ## look for lines with '1 TB'
unless(/2 TB/) {
   $str.=$_  ;     ## append lines until line with '2 TB' is reached
} 
else {
$str.= $_ ; 
push @data,$str;   ## on reaching '2 TB' push the concatenated string to array
undef $str;
}  
}

#print "\n\n$_\n\n" foreach(@data);
foreach $data1 (@data)
{
##### $data1 will be a paragraph now

}

hm...nithinpes
sorry, i think there could be a problem
cos say i wanna just the paragraph from "1 TB" to "Command Execute"
i just change to :

[CODE=perl]
foreach (@file)
{
if(/1 TB/) {$str = $_; next;}
unless (/COMMAND EXECUTED/){
$str.=$_;
}else{
$str.=$_;
push @data,$str;
undef $str;
}
}

print "$_" foreach(@data);[/CODE]

but it still prints everything as per normal
it doesn't print the paragraph from "TB 1" to "COMMAND EXECUTED"

[poolboi]

sorrie sorrie i define something wrongly in the earlier part of my script
alright it's working
thanks :)
u can go back to my previous question on "undef" and ".="
many thanks
:)

[nithinpes]

great thanks!

erm just some clarification

the opertor ".=" is an overload operator right? meaning to say it appends yr previous data

and what's the use of putting undef $str??

correct me if i'm wrong
:)

The operator ".=" is used in string concatention context.For ex:

$a = "Hello";
$b= " poolboi";
$c= $a.$b; 
print $c;  ## prints "Hello poolboi"

In this case,

$str.=$_;

is equivalent to

$str=$str.=$_;

Regarding 'undef $str'. This is used to undefine $str(delete previously stored value) inorder to avoid concatenating string for the next paragraph to previous paragraph(strin g).
But this line is actually irrelevant in the above code as the line:

if(/1 TB/) {$str = $_ ; next;}

will redefine/reassign the value from scratch whenever a line with '1 TB' pattern is seen.

[poolboi]

hm..thanks for the explanation

hm..just discovered a problem
it's similar to on top

i got these info in my textfile now

[CODE=text]
/* 3 SESSION=01547 USERID=user 2008-05-13 09:46:12 */
/* 4 ABC:DEFG=123345 56,BSERV=T22; */
/* 4c COMMAND EXECUTED */
/* 1 TBHLR HLRi VTP-11 SESSION=01548 USERID=user STARTED 2008-05-
[/CODE]

wheni use this code:
[CODE=perl]
foreach $data1 (@$data)
{
chomp ($data1);
if ($data1 =~ /4 \D\D\D:/ && $data1 !~ /3 SESSION/ && $data1 !~ /4c COMMAND/){
print "$data1\n";
}
[/CODE]
it returns me

/* 4 ABC:DEFG=123345 56,BSERV=T22; */

but when i use the paragraphing code...

[CODE=perl]
foreach (@file)
{
if(/3 SESSION/) {$str = $_; next;}
unless (/4c COMMAND/){
$str.=$_;

}else{
$str.=$_;
push @data,$str;
undef $str;
}}

foreach $data1 (@data)
{
if($data1 =~ /4c \D\D\D:/ && $data1 !~ /3 SESSION/ && $data1 !~ /4c COMMAND/){
print "$data1\n";

}}
[/CODE]
nothing returns

is there a problem with the 2nd code? i suppose it's suppose to return the same for both

[nithinpes]

That's the expected behaviour. In your first code, your are matching with one line at a time. Hence, it returns the line

/* 4 ABC:DEFG=123345 56,BSERV=T22; */

which fits all the three matching conditions that you have put.
But in the second code, you are taking one paragraph at a time. So, for the first iteration $data1 will be
/* 3 SESSION=01547 USERID=user 2008-05-13 09:46:12 */
/* 4 ABC:DEFG=123345 56,BSERV=T22; */
/* 4c COMMAND EXECUTED */
which doesn't return true for all the 3 match conditions.