I need to remove every \r \n and \ in that order from a big $string, how can I accomplish that?
Example string:
$string = '\/9jAAMAAAAB\r\nAAEAAABAAAD\/2'
need it to look like this:
$string = '/9jAAMAAAABAAEAAABAAAD/2'
#!/usr/bin/perl
$string = "something\\r\\n\\";
$string =~ s/(\\r)|(\\n)|(\\)//g;
print $string;
=> something
Here's another option:
use strict;
use warnings;
my $string = '\/9jAAMAAAAB\r\nAAEAAABAAAD\/2';
$string =~ s!\\[rn]?!!g;
print $string;
Output:
/9jAAMAAAABAAEAAABAAAD/2
Here is one way to do it:
$new_string = $string =~ s/\\|\R//g;
print "$new_string";
Related
I am trying to write a big script but I am stuck on a part. I want to sprit an array based on ".."
From the script I got this:
print #coordinates;
gene complement(872..1288)
my desired output:
complement 872 1288
I tried:
1) my #answer = split(.., #coordinates)
print("#answer\n");
2) my #answer = split /../, #coordinates;
3) print +(split /\../)[-1],[-2],[-3] while <#coordinates>
4) foreach my $anwser ( #coordinates )
{$anwser =~ s/../"\t"/;
print $anwser;}
5) my #answer = split(/../, "complement(872..1288)"); #to see if the printed array is problematic.
which prints:
) ) ) ) ) ) ) ) )
6) my #answer = split /"gene "/, #coordinates; # I tried to "catch" the entire output's spaces and tabs
which prints
0000000000000000000000000000000001000000000100000000
But none of them works. Does anyone has any idea how to step over this issue?
Ps, unfortunately, I can't run my script right now on Linux so I used this website to run my script. I hope this is not the reason why I didn't get my desired output.
my $RE_COMPLEMENT = qr{(complement)\((\d+)\.\.(\d+)\)}msx;
for my $item (#coordinates) {
my ($head, $i, $j) = $item =~ $RE_COMPLEMENT;
if (defined($head) && defined($i) && defined($j)) {
print("$head\t$i\t$j\n");
}
}
split operates on a scalar, not on an array.
my $string = 'gene complement(872..1288)';
my #parts = split /\.\./, $string;
print $parts[0]; # gene complement(872
print $parts[1]; # 1288)
To get the desired output, you can use a substitution:
my $string = 'gene complement(872..1288)';
$string =~ s/gene +|\)//g;
$string =~ s/\.\./ /;
$string =~ s/\(/ /;
Desired effect can be achieved with
use of tr operator to replace '(.)' => ' '
then splitting data string into element on space
storing only required part of array
output elements of array joined with tabulation
use strict;
use warnings;
use feature 'say';
my $data = <DATA>;
chomp $data;
$data =~ tr/(.)/ /;
my #elements = (split ' ', $data)[1..3];
say join "\t", #elements;
__DATA__
gene complement(872..1288)
Or as an alternative solution with only substitutions (without splitting data string into array)
use strict;
use warnings;
use feature 'say';
my $data = <DATA>;
chomp $data;
$data =~ s/gene\s+//;
$data =~ s/\)//;
$data =~ s/[(.]+/\t/g;
say $data;
__DATA__
gene complement(872..1288)
Output
complement 872 1288
I guess this has been asked before, but I can't find it.
Say
my $string = "something_like:this-and/that";
my #w1 = split(/_/, $string);
my #w2 = split(/-/, $w1[1]);
my #w3 = split(/:/, $w2[0]);
print $w3[1]; #print out "this"
Is there anyway to avoid the temporary array variables #w1, #w2 and #w3 and get $w3[1] directly? I remember continue split works, but forget the syntax.
Thanks.
Yes, it's possible, but would be much harder to read, so isn't advised:
my $string = "something_like:this-and/that";
my $this = (split /:/, (split /-/, (split(/_/, $string))[1])[0])[1];
print $this; #print out "this"
Alternatively, you could use a regex in this instance, but don't think it adds anything:
my $string = "something_like:this-and/that";
my ($this) = $string =~ /.*?_.*?:([^-]*)/ or warn "not found";
print $this;
Your own solution unnecessarily splits on underscores, unless your real data is significantly different from your example. You could write this
use strict;
use warnings;
my $string = "something_like:this-and/that";
my $value = (split /-/, (split /:/, $string)[1])[0];
print $value;
Or this solution uses regular expressions and does what you ask
use strict;
use warnings;
my $string = "something_like:this-and/that";
my ($value) = $string =~ /:([^_-]*)/;
print $value;
output
this
This will modify $string in place:
my $string = "something_like:this-and/that";
$string =~ s/^.*:(.+)-.*/$1/;
I want my program to divide the string by the spaces between them
$string = "hello how are you";
The output should look like that:
hello
how
are
you
You can do this is a few different ways.
use strict;
use warnings;
my $string = "hello how are you";
my #first = $string =~ /\S+/g; # regex capture non-whitespace
my #second = split ' ', $string; # split on whitespace
my $third = $string;
$third =~ tr/ /\n/; # copy string, substitute space for newline
# $third =~ s/ /\n/g; # same thing, but with s///
The first two creates arrays with the individual words, the last creates a different single string. If all you want is something to print, the last will suffice. To print an array do something like:
print "$_\n" for #first;
Notes:
Normally, regex capture requires parentheses /(\S+)/, but when the /g modifier is used, and parentheses are omitted, the entire match is returned.
When using capture this way, you need to assure list context on the assignment. If the left hand parameter is a scalar, you would force list context with parentheses: my ($var) = ...
I think like simple....
$string = "hello how are you";
print $_, "\n" for split ' ', $string;
#Array = split(" ",$string); then the #Array contain the answer
You need a split for dividing the string by spaces like
use strict;
my $string = "hello how are you";
my #substr = split(' ', $string); # split the string by space
{
local $, = "\n"; # setting the output field operator for printing the values in each line
print #substr;
}
Output:
hello
how
are
you
Split with regexp to account for extra spaces if any:
my $string = "hello how are you";
my #words = split /\s+/, $string; ## account for extra spaces if any
print join "\n", #words
I'm new to Perl and i'm trying to extract the path of a file. Please help me with a suitable regular expression, this is my code:
$string = "D:/EZ-VPN/NKEMSL0-V02.txt------vpnclient server 156.37.253.97";
I want to extract "D:/EZ-VPN/NKEMSL0-V02.txt" and "156.37.253.97" and store it in 2 scalar variables. Please suggest a regular expression to extract these.
thanks in advance
#!/usr/bin/perl
use strict;
my $string = "D:/EZ-VPN/NKEMSL0-V02.txt------vpnclient server 156.37.253.97";
$string =~ m/(.*?)--+.* (\d+\.\d+\.\d+\.\d+)/;
print $1."\n";
print $2."\n";
This should work for you.
Perl gathers the results from the regex's brackes (so called capture groups) in the $1, $2 ... $n variables.
The filename is in $1, the IP adress is in $2.
Using the string of 6 consecutive dashes to mark the end of the path:
my($path, $ipaddress) = ($string =~ m/(.*?)------.* (\d+\.\d+\.\d+\.\d+)/);
Test script:
#!/usr/bin/env perl
use strict;
use warnings;
my $string = "D:/EZ-VPN/NKEMSL0-V02.txt------vpnclient server 156.37.253.97";
my($path, $ipaddress) = ($string =~ m/(.*?)------.* (\d+\.\d+\.\d+\.\d+)/);
print "path = $path; IP = $ipaddress\n";
Output:
path = D:/EZ-VPN/NKEMSL0-V02.txt; IP = 156.37.253.97
my ($x, $y) = split /------/, $string;
my ($z) = $y =~ /(\S+)\z/;
I have a string like this
field1=1 field2=2 field3=abc
I want to ouput this as
2,1,abc
Any ideas as to how I can go about this? I can write a small C or Java program to do this, trying I'm trying to find out a simple way to do it in Perl.
use strict;
use warnings;
my $string = 'field1=1 field2=2 field3=abc';
my #values = ($string =~ m/=(\S+)/g);
print join(',', #values), "\n";
#!/usr/bin/perl
use strict;
use warnings;
# Input string
my $string = "field1=1 field2=2 field3=abc";
# Split string into a list of "key=value" strings
my #pairs = split(/\s+/,$string);
# Convert pair strings into hash
my %hash = map { split(/=/, $_, 2) } #pairs;
# Output hash
printf "%s,%s,%s\n", $hash{field2}, $hash{field1}, $hash{field3}; # => 2,1,abc
# Output hash, alternate method
print join(",", #hash{qw(field2 field1 field3)}), "\n";
Use m//g in list context:
#!/usr/bin/perl
use strict;
use warnings;
my $x = "field1=1 field2=2 field3=abc";
if ( my #matches = $x =~ /(?:field[1-3]=(\S+))/g ) {
print join(',', #matches), "\n";
}
__END__
Output:
C:\Temp> klm
1,2,abc
$_='field1=1 field2=2 field3=abc';
$,=',';
say /=(\S+)/g
Let's play Perl golf :D
my $str = 'field1=1 field2=2 field3=abc';
print(join(',', map { (split('=', $_))[1] } split(' ', $str)));
There's several ways you can do that:
Regex match
my $s = "field1=1 field2=2 field3=abc";
$s =~ /field1=(\w*) field2=(\w*) field3=(\w*)$/; //pick out each field
print $1,$2,$3;'
12abc
Split the string on match
my $s = "field1=1 field2=2 field3=abc";
my #arr = split / /, $s; print #arr,"\n"; //make an array of name=value pairs
my #vals = map { #pairs = split /=/, $_; $pairs[1] } #arr; //get the values only from each pair
print #vals'
field1=1field2=2field3=abc
12abc
Split and put in a hash (I think that's the most useful one)
my $s = "field1=1 field2=2 field3=abc";
my #arr = split / /, $s;
my %pairs = map { split=/, $_; } #arr;
print $pairs{field1}, $pairs{field2}, $pairs{field3}
12abc
Assuming your ordering was a typo:
#!/usr/bin/perl
use strict; use warnings;
my $str='a=1 b=2 c=abc';
my #v;
while ($str =~ /=(\S+)/g) {
push #v, $1;
}
print join (',', #v);
Perl is definitely the right tool for this.
#! /usr/bin/perl
$str = "field1=1 field2=2 field3=abc";
$str =~ /field1=(\S+)\ field2=(\S+)\ field3=(\S+)/;
print "$1,$2,$3", "\n";
my $a = "field1=1 field2=2 field3=abc";
my #f = split /\s*\w+=/, $a;
shift(#f);
print join(",", #f), "\n";
$string="field1=1 field2=2 field3=abc";
#s=split /\s+/,$string;
$temp=$s[1];$s[1]=$s[0];$s[0]=$temp;
foreach (#s){s/.*=//; push(#a,$_ );}
print join(",",#a);
If you actually need both the keys and the values. I would put them into a hash. You could just capture both sides of the "=", and put directly into the hash.
use strict;
use warnings;
my $str = 'field1=1 field2=2 field3=abc';
my %fields = $str =~ / (\S+) \s* = \s* (\S+) /xg;
use YAML;
print Dump \%fields
---
field1: 1
field2: 2
field3: abc
For further information please read perldoc perlre.
If you are just a beginner, you may want to read perldoc perlretut.