I have a string like "ab.cde.fg.hi", and I want to split it into two strings.
"ab.cde.fg"
".hi"
How to do so? I got some code written that will get me the 2nd string but how do I retrieve the remaining?
$mystring = "ab.cde.fg";
$mystring =~ m/.*(\..+)/;
print "$1\n";
my ($first, $second) = $string =~ /(.*)(\..*)/;
You can also use split:
my ($first, $second) = split /(?=\.[^.]+$)/, $string;
Are you sure you aren’t looking for...
($name,$path,$suffix) = File::Basename::fileparse($fullname,#suffixlist);
my #parts = /(.*)\.(.*)/s;
my #parts = split /\.(?!.*\.)/s;
my #parts = split /\.(?=[^.]*\z)/s;
Update: I misread. The "." should be included in the second part, but it's not in the above. The above should be:
my #parts = /(.*)(\..*)/s;
my #parts = split /(?=\.(?!.*\.))/s;
my #parts = split /(?=\.[^.]*\z)/s;
To promote my idea to use rindex to get
1) "ab.cde.fg"
2) ".hi"
from "ab.cde.fg.hi", I wrote this script to make experiments easier:
use strict;
use diagnostics;
use warnings;
use English;
my #tests = (
[ 'ab.cde.fg.hi', 'ab.cde.fg|.hi' ]
, [ 'abxcdexfg.hi', 'abxcdexfg|.hi' ]
);
for my $test (#tests) {
my $src = $test->[0];
my $exp = $test->[1];
printf "-----|%s| ==> |%s|-----\n", $src, $exp;
for my $op (
[ 'ikegami 1' , sub { shift =~ /(.*)\.(.*)/s; } ]
, [ 'ikegami 2' , sub { split( /\.(?!.*\.\z)/s, shift) } ]
, [ 'rindex' , sub { my $p = rindex( $_[0], '.' );
( substr($_[0], 0, $p)
, substr($_[0], $p)
); }
]
) {
my ($head, $tail) = $op->[1]( $src );
my $res = join '|', ($head, $tail);
my $ok = $exp eq $res ? 'ok' : "fail: $exp expected.";
printf "%12s: %-20s => %-20s : %s\n", $op->[0], $src, $res, $ok;
}
}
output:
-----|ab.cde.fg.hi| ==> |ab.cde.fg|.hi|-----
ikegami 1: ab.cde.fg.hi => ab.cde.fg|hi : fail: ab.cde.fg|.hi expected.
ikegami 2: ab.cde.fg.hi => ab|cde : fail: ab.cde.fg|.hi expected.
rindex: ab.cde.fg.hi => ab.cde.fg|.hi : ok
-----|abxcdexfg.hi| ==> |abxcdexfg|.hi|-----
ikegami 1: abxcdexfg.hi => abxcdexfg|hi : fail: abxcdexfg|.hi expected.
ikegami 2: abxcdexfg.hi => abxcdexfg|hi : fail: abxcdexfg|.hi expected.
rindex: abxcdexfg.hi => abxcdexfg|.hi : ok
Related
if we are in the following case:
my $str = <<EO_STR;
Name=Value1 Adress=Value4
Name=Value2 Adress=Value5
Name=Value3 Adress=Value6
EO_STR
I have a table "T1" in the database with columns: ("Name", "Address") and I want to put on the column "Name" values "value1,Value2,Value3" and on the column "Adress" values "Value4,Value5,Value6"
in this case we have :
my #matches = $str =~ /Name=(.*?)\nAdress=(.*?)\n/g;
how can we use $1 and $2 with #matches in order to get separately all occurence of Name and Adresse in order to insert them on the Table T1?
All captures of all matches are returned, so you'd have to group them up.
use List::Util 1.29 qw( pairs );
for ( pairs( $str =~ /Name=(.*) Address=(.*)/g ) ) {
my #matches = #$_;
...
}
That said, it's far more common to grab the matches iteratively.
while ($str =~ /Name=(.*) Address=(.*)/g) {
my #matches = ( $1, $2 );
...
}
Regex is not always the right tool for the job. Your data looks a lot like it's just key/value pairs. Use split to break it up. No need for a pattern match here.
Your code and data doesn't match, so I've gone with what the code said.
use strict;
use warnings;
my $str = <<EO_STR;
Name=Value1
Adress=Value4
Name=Value2
Adress=Value5
Name=Value3
Adress=Value6
EO_STR
my $fields;
foreach my $pair (split /\n/, $str) {
my ($key, $value) = split /=/, $pair;
$key =~ s/^\s+//;
push #{ $fields->{$key} }, $value;
}
use Data::Dumper;
print Dumper $fields;
The code will create this data structure:
$VAR1 = {
'Name' => [
'Value1',
'Value2',
'Value3'
],
'Adress' => [
'Value4',
'Value5',
'Value6'
]
};
You can now access these two array references and use them to insert data into your table.
I have done the following:
#!/usr/bin/env perl
use v5.28;
my $str = <<EO_STR;
Name=Value1 Adress=Value4
Name=Value2 Adress=Value5
Name=Value3 Adress=Value6
EO_STR
my #array;
for my $a (split(/\n/, $str)) {
my %res = $a =~ m/(\w+)=(\w+)/g;
push #array, \%res;
}
for my $a (#array) {
for my $b (sort keys %{$a}) {
"\n", <INPUT_FILE> ); say $b.'->'.$a->{$b};
}
}
It creates this structure:
#array = [
{
Name->Value1,
Adress->Value4
},
...
];
Can I refer to groups in a foreach loop? my code below works:
#SEP_line=grep(/,\s(SEP[A-F0-9]*),\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}),\s(\+\d+),\s.*,\s(\w+)\n$/, #lines);
foreach (#SEP_line)
{
/,\s(SEP[A-F0-9]*),\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}),\s(\+\d+),\s.*,\s(\w+)\n$/;
print $1.",".$2.",".$3.",".$4."\n";
}
Since I already specified the match regex in #SEP_line definition, I'd do something like this:
#SEP_line=grep(/,\s(SEP[A-F0-9]*),\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}),\s(\+\d+),\s.*,\s(\w+)\n$/, #lines);
foreach (#SEP_line)
{
print #SEP_line[$1].",".#SEP_line[$2].",".#SEP_line[$3]."\n";
}
This doesnt work. Thanks in advance
Why loop twice (grep, foreach)? You can do it all in one loop:
foreach my $line (#lines)
{
if ($line =~ /,\s(SEP[A-F0-9]*),\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}),\s(\+\d+),\s.*,\s(\w+)\n$/)
{
print "$1,$2,$3,$4\n";
}
}
Don't hand-parse and hand-generate CSV! It's simpler and cleaner to use a CSV parser.
use Text::CSV_XS qw( );
my $fh_in = ...;
my $fh_out = \*STDOUT;
my $csv_in = Text::CSV_XS->new({ binary => 1, auto_diag => 2, sep => ', ' });
my $csv_out = Text::CSV_XS->new({ binary => 1, auto_diag => 2 });
while ( my $row = $csv_in->getline($fh_in) ) {
$csv_out->say($fh_out, [ #$row[-4,-3,-2,-1] ]
if $row->[-4] =~ /^SEP[A-F0-9]*\z/
&& $row->[-3] =~ /^\d{1,3}(?:\.\d{1,3}){3}\z/
&& $row->[-2] =~ /^\+\d+\z/
&& $row->[-1] =~ /^\w+\z/;
}
I have many vendors in database, they all differ in some aspect of their data. I'd like to make data validation rule which is based on previous data.
Example:
A: XZ-4, XZ-23, XZ-217
B: 1276, 1899, 22711
C: 12-4, 12-75, 12
Goal: if user inputs string 'XZ-217' for vendor B, algorithm should compare previous data and say: this string is not similar to vendor B previous data.
Is there some good way/tools to achieve such comparison? Answer could be some generic algoritm or Perl module.
Edit:
The "similarity" is hard to define, i agree. But i'd like to catch to algorithm, which could analyze previous ca 100 samples and then compare the outcome of analyze with new data. Similarity may based on length, on use of characters/numbers, string creation patterns, similar beginning/end/middle, having some separators in.
I feel it is not easy task, but on other hand, i think it has very wide use. So i hoped, there is already some hints.
You may want to peruse:
http://en.wikipedia.org/wiki/String_metric and http://search.cpan.org/dist/Text-Levenshtein/Levenshtein.pm (for instance)
Joel and I came up with similar ideas. The code below differentiates 3 types of zones.
one or more non-word characters
alphanumeric cluster
a cluster of digits
It creates a profile of the string and a regex to match input. In addition, it also contains logic to expand existing profiles. At the end, in the task sub, it contains some pseudo logic which indicates how this might be integrated into a larger application.
use strict;
use warnings;
use List::Util qw<max min>;
sub compile_search_expr {
shift;
#_ = #{ shift() } if #_ == 1;
my $str
= join( '|'
, map { join( ''
, grep { defined; }
map {
$_ eq 'P' ? quotemeta;
: $_ eq 'W' ? "\\w{$_->[1],$_->[2]}"
: $_ eq 'D' ? "\\d{$_->[1],$_->[2]}"
: undef
;
} #$_
)
} #_ == 1 ? #{ shift } : #_
);
return qr/^(?:$str)$/;
}
sub merge_profiles {
shift;
my ( $profile_list, $new_profile ) = #_;
my $found = 0;
PROFILE:
for my $profile ( #$profile_list ) {
my $profile_length = #$profile;
# it's not the same profile.
next PROFILE unless $profile_length == #$new_profile;
my #merged;
for ( my $i = 0; $i < $profile_length; $i++ ) {
my $old = $profile->[$i];
my $new = $new_profile->[$i];
next PROFILE unless $old->[0] eq $new->[0];
push( #merged
, [ $old->[0]
, min( $old->[1], $new->[1] )
, max( $old->[2], $new->[2] )
]);
}
#$profile = #merged;
$found = 1;
last PROFILE;
}
push #$profile_list, $new_profile unless $found;
return;
}
sub compute_info_profile {
shift;
my #profile_chunks
= map {
/\W/ ? [ P => $_ ]
: /\D/ ? [ W => length, length ]
: [ D => length, length ]
}
grep { length; } split /(\W+)/, shift
;
}
# Psuedo-Perl
sub process_input_task {
my ( $application, $input ) = #_;
my $patterns = $application->get_patterns_for_current_customer;
my $regex = $application->compile_search_expr( $patterns );
if ( $input =~ /$regex/ ) {}
elsif ( $application->approve_divergeance( $input )) {
$application->merge_profiles( $patterns, compute_info_profile( $input ));
}
else {
$application->escalate(
Incident->new( issue => INVALID_FORMAT
, input => $input
, customer => $customer
));
}
return $application->process_approved_input( $input );
}
Here is my implementation and a loop over your test cases. Basically you give a list of good values to the function and it tries to build a regex for it.
output:
A: (?^:\w{2,2}(?:\-){1}\d{1,3})
B: (?^:\d{4,5})
C: (?^:\d{2,2}(?:\-)?\d{0,2})
code:
#!/usr/bin/env perl
use strict;
use warnings;
use List::MoreUtils qw'uniq each_arrayref';
my %examples = (
A => [qw/ XZ-4 XZ-23 XZ-217 /],
B => [qw/ 1276 1899 22711 /],
C => [qw/ 12-4 12-75 12 /],
);
foreach my $example (sort keys %examples) {
print "$example: ", gen_regex(#{ $examples{$example} }) || "Generate failed!", "\n";
}
sub gen_regex {
my #cases = #_;
my %exploded;
# ex. $case may be XZ-217
foreach my $case (#cases) {
my #parts =
grep { defined and length }
split( /(\d+|\w+)/, $case );
# #parts are ( XZ, -, 217 )
foreach (#parts) {
if (/\d/) {
# 217 becomes ['\d' => 3]
push #{ $exploded{$case} }, ['\d' => length];
} elsif (/\w/) {
#XZ becomes ['\w' => 2]
push #{ $exploded{$case} }, ['\w' => length];
} else {
# - becomes ['lit' => '-']
push #{ $exploded{$case} }, ['lit' => $_ ];
}
}
}
my $pattern = '';
# iterate over nth element (part) of each case
my $ea = each_arrayref(values %exploded);
while (my #parts = $ea->()) {
# remove undefined (i.e. optional) parts
my #def_parts = grep { defined } #parts;
# check that all (defined) parts are the same type
my #part_types = uniq map {$_->[0]} #def_parts;
if (#part_types > 1) {
warn "Parts not aligned\n";
return;
}
my $type = $part_types[0]; #same so make scalar
# were there optional parts?
my $required = (#parts == #def_parts);
# keep the values of each part
# these are either a repitition or lit strings
my #values = sort uniq map { $_->[1] } #def_parts;
# these are for non-literal quantifiers
my $min = $required ? $values[0] : 0;
my $max = $values[-1];
# write the specific pattern for each type
if ($type eq '\d') {
$pattern .= '\d' . "{$min,$max}";
} elsif ($type eq '\w') {
$pattern .= '\w' . "{$min,$max}";
} elsif ($type eq 'lit') {
# quote special characters, - becomes \-
my #uniq = map { quotemeta } uniq #values;
# join with alternations, surround by non-capture grouup, add quantifier
$pattern .= '(?:' . join('|', #uniq) . ')' . ($required ? '{1}' : '?');
}
}
# build the qr regex from pattern
my $regex = qr/$pattern/;
# test that all original patterns match (#fail should be empty)
my #fail = grep { $_ !~ $regex } #cases;
if (#fail) {
warn "Some cases fail for generated pattern $regex: (#fail)\n";
return '';
} else {
return $regex;
}
}
To simplify the work of finding the pattern, optional parts may come at the end, but no required parts may come after optional ones. This could probably be overcome but it might be hard.
If there was a Tie::StringApproxHash module, it would fit the bill here.
I think you're looking for something that combines the fuzzy-logic functionality of String::Approx and the hash interface of Tie::RegexpHash.
The former is more important; the latter would make light work of coding.
This is a follow up to the question posted here: Perl Regex syntax
The results from that discussion yielded this script:
#!/usr/bin/env perl
use strict;
use warnings;
my #lines = <DATA>;
my $current_label = '';
my #ordered_labels;
my %data;
for my $line (#lines) {
if ( $line =~ /^\/(.*)$/ ) { # starts with slash
$current_label = $1;
push #ordered_labels, $current_label;
next;
}
if ( length $current_label ) {
if ( $line =~ /^(\d) "(.*)"$/ ) {
$data{$current_label}{$1} = $2;
next;
}
}
}
for my $label ( #ordered_labels ) {
print "$label <- as.factor($label\n";
print " , levels= c(";
print join(',',map { $_ } sort keys %{$data{$label}} );
print ")\n";
print " , labels= c(";
print join(',',
map { '"' . $data{$label}{$_} . '"' }
sort keys %{$data{$label}} );
print ")\n";
print " )\n";
}
__DATA__
...A bunch of nonsense I do not care about...
...
Value Labels
/gender
1 "M"
2 "F"
/purpose
1 "business"
2 "vacation"
3 "tiddlywinks"
execute .
Essentially, I need to build the Perl to accommodate a syntax shorthand found in the SPSS file. For adjacent columns, SPSS allows one to type something like:
VALUE LABELS
/agree1 to agree5
1 "Strongly disagree"
2 "Disagree"
3 "Neutral"
4 "Agree"
5 "Strongly agree"
As the script currently exists, it will generate this:
agree1 to agree5 <- factor(agree1 to agree5
, levels= c(1,2,3,4,5,6)
, labels= c("Strongly disagree","Disagree","Neutral","Agree","Strongly agree","N/A")
)
and I need it to produce something like this:
agree1 <- factor(agree1
, levels= c(1,2,3,4,5,6)
, labels= c("Strongly disagree","Disagree","Neutral","Agree","Strongly agree","N/A")
)
agree2 <- factor(agree2
, levels= c(1,2,3,4,5,6)
, labels= c("Strongly disagree","Disagree","Neutral","Agree","Strongly agree","N/A")
)
…
use strict;
use warnings;
main();
sub main {
my #lines = <DATA>;
my $vlabels = get_value_labels(#lines);
write_output_delim($vlabels);
}
# Extract the value label information from SPSS syntax.
sub get_value_labels {
my (#vlabels, $i, $j);
for my $line (#_){
if ( $line =~ /^\/(.+)/ ){
my #vars = parse_var_range($1);
$i = #vlabels;
$j = $i + #vars - 1;
push #vlabels, { var => $_, codes => [] } for #vars;
}
elsif ( $line =~ /^\s* (\d) \s+ "(.*)"$/x ){
push #{$vlabels[$_]{codes}}, [$1, $2] for $i .. $j;
}
}
return \#vlabels;
}
# A helper function to handle variable ranges: "agree1 to agree3".
sub parse_var_range {
my $vr = shift;
my #vars = split /\s+ to \s+/x, $vr;
return $vr unless #vars > 1;
my ($stem) = $vars[0] =~ /(.+?)\d+$/;
my #n = map { /(\d+)$/ } #vars;
return map { "$stem" . $_ } $n[0] .. $n[1];
}
sub write_output_delim {
my $vlabels = shift;
for my $vlab (#$vlabels){
print $vlab->{var}, "\n";
print join("\t", '', #$_), "\n" for #{$vlab->{codes}}
}
}
sub write_output_factors {
# You get the idea...
}
__DATA__
/gender
1 "M"
2 "F"
/purpose
1 "business"
2 "vacation"
3 "tiddlywinks"
/agree1 to agree3
1 "Disagree"
2 "Neutral"
3 "Agree"
I have a string such as 'xxox-x' that I want to mask each line in a file against as such:
x's are ignored (or just set to a known value)
o's remain unchanged
the - is a variable length field that will keep everything else unchanged
therefore mask 'xxox-x' against 'deadbeef' would yield 'xxaxbeex'
the same mask 'xxox-x' against 'deadabbabeef' would yield 'xxaxabbabeex'
How can I do this succinctly preferrably using s operator?
$mask =~ s/-/'o' x (length $str - length $mask)/e;
$str =~ s/(.)/substr($mask, pos $str, 1) eq 'o' ? $1 : 'x'/eg;
$ perl -pe 's/^..(.).(.+).$/xx$1x$2x/;'
deadbeef
xxaxbeex
deadabbabeef
xxaxabbabeex
Compile your pattern into a Perl sub:
sub compile {
use feature 'switch';
my($pattern) = #_;
die "illegal pattern" unless $pattern =~ /^[-xo]+$/;
my($search,$replace);
my $i = 0;
for (split //, $pattern) {
given ($_) {
when ("x") {
$search .= "."; $replace .= "x";
}
when ("o") {
$search .= "(?<sub$i>.)";
$replace .= "\$+{sub$i}";
++$i;
}
when ("-") {
$search .= "(?<sub$i>.*)";
$replace .= "\$+{sub$i}";
++$i;
}
}
}
my $code = q{
sub {
local($_) = #_;
s/^SEARCH$/REPLACE/s;
$_;
}
};
$code =~ s/SEARCH/$search/;
$code =~ s/REPLACE/$replace/;
#print $code;
local $#;
my $sub = eval $code;
die $# if $#;
$sub;
}
To be more concise, you could write
sub _patref { '$+{sub' . $_[0]++ . '}' }
sub compile {
my($pattern) = #_;
die "illegal pattern" unless $pattern =~ /^[-xo]+$/;
my %gen = (
'x' => sub { $_[1] .= '.'; $_[2] .= 'x' },
'o' => sub { $_[1] .= "(?<sub$_[0]>.)"; $_[2] .= &_patref },
'-' => sub { $_[1] .= "(?<sub$_[0]>.*)"; $_[2] .= &_patref },
);
my($i,$search,$replace) = (0,"","");
$gen{$1}->($i,$search,$replace)
while $pattern =~ /(.)/g;
eval "sub { local(\$_) = \#_; s/\\A$search\\z/$replace/; \$_ }"
or die $#;
}
Testing it:
use v5.10;
my $replace = compile "xxox-x";
my #tests = (
[ deadbeef => "xxaxbeex" ],
[ deadabbabeef => "xxaxabbabeex" ],
);
for (#tests) {
my($input,$expect) = #$_;
my $got = $replace->($input);
print "$input => $got : ", ($got eq $expect ? "PASS" : "FAIL"), "\n";
}
Output:
deadbeef => xxaxbeex : PASS
deadabbabeef => xxaxabbabeex : PASS
Note that you'll need Perl 5.10.x for given ... when.
x can be translated to . and o to (.) whereas - becomes (.+?):
#!/usr/bin/perl
use strict; use warnings;
my %s = qw( deadbeef xxaxbeex deadabbabeef xxaxabbabeex);
for my $k ( keys %s ) {
(my $x = $k) =~ s/^..(.).(.+?).\z/xx$1x$2x/;
print +($x eq $s{$k} ? 'good' : 'bad'), "\n";
}
heres a quick stab at a regex generator.. maybe somebody can refactor something pretty from it?
#!/usr/bin/perl
use strict;
use Test::Most qw( no_plan );
my $mask = 'xxox-x';
is( mask( $mask, 'deadbeef' ), 'xxaxbeex' );
is( mask( $mask, 'deadabbabeef' ), 'xxaxabbabeex' );
sub mask {
my ($mask, $string) = #_;
my $regex = $mask;
my $capture_index = 1;
my $mask_rules = {
'x' => '.',
'o' => '(.)',
'-' => '(.+)',
};
$regex =~ s/$_/$mask_rules->{$_}/g for keys %$mask_rules;
$mask =~ s/$_/$mask_rules->{$_}/g for keys %$mask_rules;
$mask =~ s/\./x/g;
$mask =~ s/\([^)]+\)/'$' . $capture_index++/eg;
eval " \$string =~ s/^$regex\$/$mask/ ";
$string;
}
Here's a character by character solution using substr rather that split. It should be efficient for long strings since it skips processing the middle part of the string (when there is a dash).
sub apply_mask {
my $mask = shift;
my $string = shift;
my ($head, $tail) = split /-/, $mask;
for( 0 .. length($head) - 1 ) {
my $m = substr $head, $_, 1;
next if $m eq 'o';
die "Bad char $m\n" if $m ne 'x';
substr($string, $_, 1) = 'x';
}
return $string unless defined $tail;
$tail = reverse $tail;
my $last_char = length($string) - 1;
for( 0 .. length($tail) - 1 ) {
my $m = substr $tail, $_, 1;
next if $m eq 'o';
die "Bad char $m\n" if $m ne 'x';
substr($string, $last_char - $_, 1) = 'x';
}
return $string;
}
sub mask {
local $_ = $_[0];
my $mask = $_[1];
$mask =~ s/-/'o' x (length($_)-(length($mask)-1))/e;
s/(.)/substr($mask, pos, 1) eq 'o' && $1/eg;
return $_;
}
Used tidbits from a couple answers ... this is what I ended up with.
EDIT: update from comments