How can I format each line while reading a file? - perl

Input format:
2014-09-21 00:09:22,718 TRACE [user: admin12] common.Log (PerformanceExtractor.Python:9776) - ClientId:895,UserId:258,Ip:111.1.1.1,DurationMls:23,DurationString:0.023 seconds,Url:Calculate.LoanExmple
My output would be into variables; for example:
$date = 2014-09-21 00:09:22,718 $user = admin12 $ClientId= 895 $UserID=258 $ip = 111.1.1.1 $time=0.023 $url=Calculate.LoanExmple
In JAVA I would tackle this using a loop, a Stream Object, and a regular expression. I have no idea how to tackle this using Perl. I will also insert this variable as a column into a database and the line will be at least 3000 max 5000 each time i will launch the .pl.
my loop is
{
print $line;
--formatting here?
last if $. == 500;
}
This just prints out the line as above - I guess the best solution would be to format it and get the values into variables while reading each line, ready to INSERT into DB with DBI libraries.
any suggestions?

Something like this?
while (<$fh>) {
my #fields = m{^
(\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:[\d,]+)
\s TRACE \s
\[user:\s(\w+)]
\s common.Log \s \(PerformanceExtractor\.Python\:\d+\) \s - \s
ClientId:(\d+),
UserId:(\d+),
Ip:([\d.]+),
DurationMls:\d+,
DurationString:([\d.]+) \s seconds,
Url:(\S+)
$}x
or next; # skip lines which don't match regexp
printf('$date=%s; $user=%s; $client_id=%s; $user_id=%s; $ip=%s; $time=%s; $url=%s', #fields);
print "\n";
}

Related

Reading CSV with Perl produces distorted lines

I am reading a CSV file using Perl 5.26.1 with lines that look like this:
B1_10,202337840166,R08C02,202337840166_R08C02.gtc
I'm reading this data into a hash that has the last element as a key, and the first as a value.
I read the file line by line (snippet only):
while (<$csv>) {
if (/^Sample/) { next }
say "-----start----\noriginal = $_";
chomp;
my #line = split /,/;
my $name = $line[0];
my $vcf = $line[3];
say "1st element = $name";
say "4th element = $vcf";
$vcf2dir{$vcf} = $name;
say "\$vcf2dir{$vcf} = '$name'";
say '-----end------';
}
which produces the following output:
-----start----
original = B1_10,202337840166,R08C02,202337840166_R08C02.gtc
1st element = B1_10
4th element = 202337840166_R08C02.gtc
} = 'B1_10'2337840166_R08C02.gtc
-----end-------
but it should look like
-----start----
original = B1_10,202337840166,R08C02,202337840166_R08C02.gtc
1st element = B1_10
4th element = 202337840166_R08C02.gtc
$vcf2dir{202337840166_R08C02.gtc} = 'B1_10'
-----end-------
and it shows strangely with the data printer package:
use DDP;
p %vcf2dir;
produces
{
' "B1_10"840166_R08C02.gtc
}
in other words, the last string is being cut up for some reason.
I have tried removing non-ascii characters with $_ =~ s/[[:^ascii:]]//g; but this still produces the same error.
I have no idea why Perl is ripping these strings apart :(
while (<$csv>) {
...
chomp;
My guess is that the input file has as line end \r\n (windows style) while you are executing the code in a UNIX like environment (Linux, Mac...) where the line end is \n. This means that $INPUT_RECORD_SEPARATOR is also \n and that chomp only removes the \n and leaves the \r. This left \r causes such strange output.
To fix this either fix the line endings in your input file, set $INPUT_RECORD_SEPARATOR to the expected separator or just do s{\r?\n\z}{} instead of chomp to handle both \r\n and \n line endings.
I ran your snippet against your line and it worked as expected
But I have had behavior like what you show because a spurious Control-M's in my data.
Try filtering for control-M's
after your chomp replace all control-M's with the command below
s/\cM//g;

Best way to parse string in perl

To achieve below task I have written below C like perl program (As I am new to Perl), But I am not sure if this is the best way to achieve.
Can someone please guide?
Note: Not with the full program, But where I can make improvement.
Thanks in advance
Input :
$str = "mail1, local<mail1#mail.local>, mail2#mail.local, <mail3#mail.local>, mail4 local<mail4#mail.local>"
Expected Output :
mail1, local<mail1#mail.local>
mail2#mail.local
<mail3#mail.local>
mail4, local<mail4#mail.local>
Sample Program
my $str="mail1, \#local<mail1\#mail.local>, mail2\#mail.local, <mail3\#mail.local>, mail4, local<mail4\#mail.local>";
my $count=0, #array, $flag=0, $tempStr="";
for my $c (split (//,$str)) {
if( ($count eq 0) and ($c eq ' ') ) {
next;
}
if($c) {
if( ($c eq ',') and ($flag eq 1) ) {
push #array, $tempStr;
$count=0;
$flag1=0;
$tempStr="";
next;
}
if( ($c eq '>' ) or ( $c eq '#' ) ) {
$flag=1;
}
$tempStr="$tempStr$c";
$count++;
}
}
if($count>0) {
push #array, $tempStr;
}
foreach my $var (#array) {
print "$var\n";
}
Edit:
Input:
Input is the output of above code.
Expected Output :
"mail1, local"<mail1#mail.local>
"mail4, local"<mail4#mail.local>
Sample Code:
$str =~ s/([^#>]+[#>][^,]+),\s*/$1\n/g;
my #addresses = split('\n',$str);
if(scalar #addresses) {
foreach my $address (#addresses) {
if (($address =~ /</) and ($address !~ /\"/) and ($address !~ /^</)){
$address="\"$address";
$address=~ s/</\"</g;
}
}
$str = join(',',#addresses);
}
print "$str\n";
As I see, you want to replace each:
comma and following spaces,
occurring after either # or >,
with a newline.
To make such replacement, instead of writing a parsing program, you can use
a regex.
The search part can be as follows:
([^#>]+[#>][^,]+),\s*
Details:
( - Start of the 1st capturing group.
[^#>]+ - A non-empty sequence of chars other than # or >.
[#>] - Either # or >.
[^,]+ - A non-empty sequence of chars other than a comma.
) - End of the 1st capturing group.
,\s* - A comma and optional sequence of spaces.
The replace part should be:
$1 - The 1st capturing group.
\n - A newline.
So the whole program, much shorter than yours, can be as follows:
my $str='mail1, local<mail1#mail.local>, mail2#mail.local, <mail3#mail.local>, mail4, local<mail4#mail.local>';
print "Before:\n$str\n";
$str =~ s/([^#>]+[#>][^,]+),\s*/$1\n/g;
print "After:\n$str\n";
To replace all needed commas I used g option.
Note that I put the source string in single quotes, otherwise Perl
would have complained about Possible unintended interpolation of #mail.
Edit
Your modified requirements must be handled different way.
"Ordinary" replacement is not an option, because now there are some
fragments to match and some framents to ignore.
So the basic idea is to write a while loop with a matching regex:
(\w+),?\s+(\w+)(<[^>]+>), meaning:
(\w+) - First capturing group - a sequence of word chars (e.g. mail1).
,?\s+ - Optional comma and a sequence of spaces.
(\w+) - Second capturing group - a sequence of word chars (e.g. local).
(<[^>]+>) - Third capturing group - a sequence of chars other than >
(actual mail address), enclosed in angle brackets, e.g. <mail1#mail.local>.
Within each execution of the loop you have access to the groups
captured in this particular match ($1, $2, ...).
So the content of this loop is to print all these captured groups,
with required additional chars.
The code (again much shorter than yours) should look like below:
my $str = 'mail1, local<mail1#mail.local>, mail2#mail.local, <mail3#mail.local>, mail4 local<mail4#mail.local>';
while ($str =~ /(\w+),?\s+(\w+)(<[^>]+>)/g) {
print "\"$1, $2\"$3\n";
}
Here is an approach using split, which in this case also needs a careful regex
use warnings;
use strict;
use feature 'say';
my $string = # broken into two parts for readabililty
q(mail1, local<mail1#mail.local>, mail2#mail.local, )
. q(<mail3#mail.local>, mail4, local<mail4#mail.local>);
my #addresses = split /#.+?\K,\s*/, $string;
say for #addresses;
The split takes a full regex in its delimiter specification. In this case I figure that each record is delimited by a comma which comes after the email address, so #.+?,
To match a pattern only when it is preceded by another brings to mind a negative lookbehind before the comma. But those can't be of variable length, which is precisely the case here.
We can instead normally match the pattern #.+? and then use the \K form (of the lookbehind) which drops all previous matches so that they are not taken out of the string. Thus the above splits on ,\s* when that is preceded by the email address, #... (what isn't consumed).
It prints
mail1, local<mail1#mail.local>
mail2#mail.local
<mail3#mail.local>
mail4, local<mail4#mail.local>
The edit asks about quoting the description preceding <...> when it's there. A simple way is to make another pass once addresses have been parsed out of the string as above. For example
my #addresses = split /#.+?\K,\s*/, $string; #/ stop syntax highlight
s/(.+?,\s*.+?)</"$1"</ for #addresses;
say for #addresses;
The regex in a loop is one way to change elements of an array. I use it for its efficiency (changes elements in place), conciseness, and as a demonstration of the following properties.
In a foreach loop the index variable (or $_) is an alias for the currently processed element – so changing it changes that element. This is a known source of bugs when allowed unknowingly, which was another reason to show it in the above form.
The statement also uses the statement modifier and it is equivalent to
foreach my $elem (#addresses) {
$elem =~ s/(.+?,\s*.+?)</"$1"</;
}
This is often considered a more proper way to write it but I find that the other form emphasizes more clearly that elements are being changed, when that is the sole purpose of the foreach.

issue in matching regexp in perl

I am having following code
$str = "
OTNPKT0553 04-02-03 21:43:46
M X DENY
PLNA
/*Privilege, Login Not Active*/
;";
$val = $str =~ /[
]*([\n]?[\n]+
[\n]?) ([^;^
]+)/s;
print "$1 and $2";
Getting output as
and PLNA
Why it is getting PLNA as output. I believe it should stop at first\n. I assume output should be OTNPKT0553 04-02-03 21:43:46
Your regex is messy and contains a lot of redundancy. The following steps demonstrate how it can be simplified and then it becomes more clear why it is matching PLNA.
1) Translating the literal new lines in your regex:
$val = $str =~ /[\n\n]*([\n]?[\n]+\n[\n]?) ([^;^\n]+)/s;
2) Then simplifying this code to remove the redundancy:
$val = $str =~ /(\n{2}) ([^;^\n]+)/s;
So basically, the regex is looking for two new lines followed by 3 spaces.
There are three spaces before OTNPKT0553, but there is only a single new line, so it won't match.
The next three spaces are before PLNA which IS preceded by two new lines, and so matches.
You have a whole lot of newlines in there - some literal and some encoded as \n. I'm not clear how you were thinking. Did you think \n matched a number maybe? A \d matches a digit, and will also match many Unicode characters that are digits in other languages. However for simple ASCII text it works fine.
What you need is something like this
use strict;
use warnings;
my $str = "
OTNPKT0553 04-02-03 21:43:46
M X DENY
PLNA
/*Privilege, Login Not Active*/
;";
my $val = $str =~ / (\w+) \s+ ( [\d-]+ \s [\d:]+ ) /x;
print "$1 and $2";
output
OTNPKT0553 and 04-02-03 21:43:46
You have an extra line feed, change the regex to:
$str =~ /[
]*([\n]?[\n]+[\n]?) ([^;^
]+)/s;
and simpler:
$str =~ /\n+ ([^;^\n]+)/s;

Extracting alphanumeric phrase from a string

Trying to extract the alphanumeric characters from this string:
A_phase_I-II,_open-req_project_id_PX15RAD001
The problem is: the term PX15RAD001 can occur anywhere in the string.
Trying to extract the alpha-numeric part using the below expression. But this returns the entire string. I thought Alum was a valid keyword for alpha-numerics. Is that not the case?
(my $string = $line ) =~ s/\P{Alnum}//g;
print $string;
How can I extract the alphanumeric part of the afore mentioned string?
Thanks in advance.
-simak
At the end as per your input:
> echo "A_phase_I-II,_open-req_project_id_PX15RAD001"|perl -lne 'print $1 if(/id_([A-Z0-9]*)/)'
PX15RAD001
In the middle:
> echo "A_phase_I-II,_open-req_id_PX15RAD001_project" | perl -lne 'print $1 if(/id_([A-Z0-9]*)/)'
PX15RAD001
or in your terms:
$line=~m/id_([A-Z0-9]*)/g;
print $1;
Here are some testcases, produced with the comments of #Vijay s Answer:
my #line = (
'A_phase_I-II,_open-req_project_id_PX15RAD001',
'_PX15RAD001_A_phase_I-II,_open-req_project_id',
'A_pha3333se_I-II,_ope_PX15RAD001_n-req_project',
'A_phase_I-II,_PX15RAD001_open-req_projec123123123t_id',
'A_phase_I-II_PX15RAD001_roject_id'
);
foreach my $string ( #line ) {
$string =~ m{_([^_]{10})_?}g;
print $1 . "\n" if $1;
}
These kinds of questions are hard to answer because there is not enough information. What information we have is:
You say your target string is "alphanumeric", but the entire input string is alphanumeric, except for some punctuation, so that really doesn't tell us anything.
You say it is 12 characters long, but the sample you show is 10 characters long.
You seem to think that "alphanumeric" does not include underscore.
So, the reliable information I can sense from you is:
Target string is always delimited by underscore _
Target string is 10-12 characters, all alphanumeric except underscore.
The "reliable" solution based on this rather skimpy information is:
my $str = "A_phase_I-II,_open-req_project_id_PX15RAD001";
for my $field (split /_/, $str) {
if (length($field) <= 12 and
length($field) >= 10 and # field is 10-12 characters
$field !~ /\W/) { # and contains no non-alphanumerics
# do something
}
}
By splitting on underscore, we can easily isolate each field in the string and perform simpler tests on it, such as the ones above.

Trying to understand Perl split() output

I have a few lines of text that I'm trying to use Perl's split function to convert into an array. The problem is that I'm getting some unusual extra characters in the output, specifically the following string "\cM" (without the quotes). This string appears where there were line breaks in the original text; however, (I believe) those line breaks were removed in the text that I'm trying to split. Does anybody know what's going on with this phenomenon? I posted an example below. Thanks.
Here's the original plain text that I'm trying to split. I'm loading it from a file, in case that matters:
10b2obo12b2o2b$6b3obob3o8bob3o2b$2bobo10bo3b2obo4bo2b$2o4b2o5bo3b4obo
3b2o2b$2bob2o2bo4b3obo5b4obob$8bo4bo13b3o$2bob2o2bo4b3obo5b4obob$2o4b
2o5bo3b4obo3b2o2b$2bobo10bo3b2obo4bo2b$6b3obob3o8bob3o2b$10b2obo12b2o!
Here is my Perl code that is supposed to do the splitting:
while(<$FH>) {
chomp;
$string .= $_;
last if m/!$/;
}
#rows = split(qr/\$/, $string);
print; # a dummy line to provide a breakpoint for the debugger
This what the debugger outputs when it gets to the "print" line. The issue I'm trying to deal with appears in lines 3, 7, and 10:
DB<10> p $string
2o5bo3b4obo3b2o2b$2bobo10bo3b2obo4bo2b$6b3obob3o8bob3o2b$10b2obo12b2o!
DB<11> x #rows
0 '10b2obo12b2o2b'
1 '6b3obob3o8bob3o2b'
2 '2bobo10bo3b2obo4bo2b'
3 "2o4b2o5bo3b4obo\cM3b2o2b"
4 '2bob2o2bo4b3obo5b4obob'
5 '8bo4bo13b3o'
6 '2bob2o2bo4b3obo5b4obob'
7 "2o4b\cM2o5bo3b4obo3b2o2b"
8 '2bobo10bo3b2obo4bo2b'
9 '6b3obob3o8bob3o2b'
10 "10b2obo12b2o!\cM"
You know, changing the file input separator would make this code a lot simpler.
$/ = '$';
my #rows = <$FH>;
chomp #rows;
print "#rows";
The debugger is probably using \cM to represent Ctrl-M which is also known as a carriage return (and sometimes \r or ^M). Text files from Windows use a CR-LF (carriage return, line feed) pair to represent the end of a line. If you read such a file on a Unix system, your chomp will strip off the Unix EOL (a single line feed) but leave the CR as is and you end up with stray CRs in your file.
For a file like you have you can just strip out all the trailing whitespace instead of using chomp:
while(defined(my $line = <$FH>)) {
$line =~ s/\s+$//;
$string .= $line;
last if($line =~ /!$/);
}
You don't say which OS you're on.
Check out binmode and what it has to say about \cM, and that their position coincides with the line endings of your input file:
http://perldoc.perl.org/functions/binmode.html