Program is based on a man walking around a city (Perl) - perl

I am trying to read a file that contains the letters 'n', 's', 'e', 'w'.
How do I look for these letters and add them to a variable called $ns and $ew,
$ns means to add 'n' or subtract 's'.
$ew means to add 'e' or subtract 'w'.
This is what I have:
open (FILE, 'randwalk1')
or die "Could not open file";
my $ns = 0;
my $ew = 0;
while (my $file1 = <FILE>) {
if ($file1 =~ /n+/) {
$ns = $ns + 1;
} elsif ($file1 =~ /s/) {
$ns = $ns - 1;
} elsif ($file1 =~ /e/) {
$ew = $ew + 1;
} elsif ($file1 =~ /w/) {
$ew = $ew - 1;
}
}
The input file (randwalk1) looks like:
ensweswewnnewwwsweenwsssssnewwennnesewewwewsnnewwwsewsenssns‌
newnwssswennesnseewn‌​wsnwnwnnwwwewes
neesnwnsenwsnnnewwswnnneesswssnswenwsnnwewswwsnennneeeeswewe‌​

You check if the line has an n, you find one, then you ignore the rest of the line. You need to check each character of the line.
my $home_returns = 0;
my $ns = 0;
my $ew = 0;
while (my $line = <>) {
chomp($line);
for my $char (split //, $line) {
if ($char eq "n") { ++$ns; }
elsif ($char eq "s") { --$ns; }
elsif ($char eq "e") { ++$ew; }
elsif ($char eq "w") { --$ew; }
++$home_returns if $ns == 0 && $ew == 0;
}
}
or
my $home_returns = 0;
my %counts = map { $_ => 0 } qw( n s e w );
while (my $line = <>) {
chomp($line);
for my $char (split //, $line) {
++$counts{$char};
++$home_returns
if $counts{n} == $counts{s}
&& $counts{e} == $counts{w};
}
}

Related

How to grep string and assign it to a variable in Perl

I have a file with the below details;
file name: allappsclus
cont:i-02dd208bf1d81c254
rs:i-0098ad0b59b7fe7cf
I want to use the value for i-XXX"= in associated cont name and assign it to another variable.
If run my code and get an output it is
test-1.1.0.0
1insideif-CNS
use strict;
use warnings;
use Data::Dumper;
my $jupyter = 0;
my $controller = 0;
my $rstudio = 0;
my $zeppelin = 0;
my $fh= '/tmp/allappsclus';
open my $fh2, '<', $fh or die "Cannot open file: $!\n";
while ( <$fh2> ) {
if ( $_ =~ /jup/ ) {
$jupyter = 1;
}
elsif ( $_ =~ /con/ ) {
$controller = 1;
}
elsif ( $_ =~ /rs/ ) {
$rstudio = 1;
}
elsif ( $_ =~ /zep/ ) {
$zeppelin = 1;
}
}
print "test-$rs.$con.$jup.$zep\n";
if ( $zepeq '0' && $jup eq '0' && $con eq '1' && $rs eq '1' ) {
print "insideif-CNS";
}
else {
print "do nothing";
}
close $fh;
close $fh2;
Now I want to print the value i-02dd208bf1d81c254 instead of CNS in the output.
$myStr = "cont:i-02dd208bf1d81c254 rs:i-0098ad0b59b7fe7cf";
if ($myStr =~ /cont:([^ ]+)/) # match the full pattern with the value you required
{
$controller=1;
$cont = $1; # assign required value to a variable
}
print $cont; # print the variable
This might work for you.

Caesar Cipher -- "Isn't numeric in addition (+)"

I'm creating a Caesar cipher using Perl, but I cant seem to find the error in the code.
I keep getting the error message:
Argument "hello" isn't numeric in addition (+) at ./Lab03.pl line 66, <> line 1.
which is the line $translated += $symbol.
use warnings;
$x = 26;
sub getMode {
$e = "encrypt decrypt";
while ( 'True' ) {
print "Do you wish to encrypt or decrypt a message? \n";
$mode = <STDIN>;
chomp( $mode );
if ( $mode = split( //, $e ) ) {
return $mode;
}
else {
print "Enter either 'encrypt' or 'decrypt'.\n";
}
}
}
sub getMessage {
print "Enter your message:";
$input = <STDIN>;
chomp( $input );
return $input;
}
sub getKey {
$key = 0;
while ( 'True' ) {
print "Enter the key number (1-26): ";
$key = int( <> );
chomp( $key );
if ( $key >= 1 and $key <= $x ) {
return $key;
}
}
}
sub getTranslatedMessage {
( $mode, $message, $key ) = #_;
if ( $mode =~ /^d/ ) {
$key = -$key;
$translated = '';
}
foreach $symbol ( $message ) {
if ( $symbol =~ /[A-Za-z]/ ) {
$num = ord( $symbol );
$num += $key;
}
if ( $symbol =~ /^[A-Z]/ ) {
if ( $num > ord( 'Z' ) ) {
$num -= 26;
}
elsif ( $num < ord( 'A' ) ) {
$num += 26;
}
elsif ( $symbol = /^[a-z]/ ) {
if ( $num > ord( 'z' ) ) {
$num -= 26;
}
elsif ( $num < ord( 'a' ) ) {
$num += 26;
}
$translated += chr( $num );
}
}
else {
$translated += $symbol;
}
}
return $translated;
}
$mode = getMode();
$message = getMessage();
$key = getKey();
print "Your translated text is: '\n' ";
print( getTranslatedMessage( $mode, $message, $key ) );
In Perl, + is numeric addition only. String concatenation is . / .=.
Also:
if ($mode = split(//,$e)){
is incorrect. I believe you want something like:
my %valid_mode = ( 'encrypt' => 1, 'decrypt' => 1);
...
if ( $valid_mode{$mode} ) {
return $mode
The code you have is setting $mode into the number of characters in $e (in an inefficient way).
Here:
foreach $symbol ($message){
in Perl, strings are first class entities; they aren't automatically interpreted as arrays of characters. So to loop over the characters, you need to so something else. The simplest way is:
foreach $symbol ( split //, $message ) {
Here:
elsif ($symbol= /^[a-z]/){
= should be =~.
There is also a problem with which code is in which blocks that prevents upper case characters from being added to the output. It looks to me like the closing brace for your fir st if ($symbol =~ should be just before the later else, and other braces possibly fixed up to match.
Putting all your }'s on a line of their own, indented the same as the line with the corresponding { is a much better idea. It will help you see mismatched braces much more easily.
Here is corrected code, with use strict added and all variables declared:
use warnings;
use strict;
my $x = 26;
sub getMode{
my %valid_mode = ( 'encrypt' => 1, 'decrypt' => 1 );
while ('True'){
print"Do you wish to encrypt or decrypt a message? \n";
my $mode = <STDIN>;
chomp ( $mode);
if ($valid_mode{$mode}) {
return $mode;
}
else {
print "Enter either 'encrypt' or 'decrypt'.\n";
}
}
}
sub getMessage{
print"Enter your message:";
my $input = <STDIN>;
chomp ($input);
return $input;
}
sub getKey{
my $key = 0;
while ('True'){
print"Enter the key number (1-26): ";
$key = int(<>);
chomp ($key);
if ($key >= 1 and $key <= $x){
return $key;
}
}
}
sub getTranslatedMessage{
my ($mode, $message, $key) = #_;
if ($mode =~ /^d/){
$key = -$key;
}
my $translated = '';
foreach my $symbol (split //, $message){
if ($symbol =~ /[A-Za-z]/){
my $num = ord($symbol);
$num += $key;
if ($symbol =~ /^[A-Z]/){
if ($num > ord('Z')){
$num -= 26;
}
elsif ($num < ord('A')){
$num += 26;
}
}
elsif ($symbol=~ /^[a-z]/){
if ($num > ord('z')){
$num -= 26;
}
elsif ($num < ord('a')){
$num += 26;
}
}
$translated .= chr($num);
}
else{
$translated .= $symbol;
}
}
return $translated;
}
my $mode = getMode();
my $message = getMessage();
my $key = getKey();
print"Your translated text is:\n";
print(getTranslatedMessage($mode, $message, $key));
print "\n";
Over all, I suggest you write smaller chunks of code and test them to make sure they worked before assembling them all together.

How to make this Perl program print in descending order?

This code works but it prints in ascending order. Do I need to change my whole formula?
print "Enter an integer \n";
my $root = <STDIN>;
my #nums = (100..200);
my $i = 0;
# code in while loop executes as long as condition is true
while ( $i < $#nums )
{
print "$nums[$i]\n",if($nums[$i] % $root == 0); $i++;
}
Just set $i to $#nums instead of 0 and decrement it -- instead of incrementing. You'll need to change the loop condition to $i >= 0 (it should be $i <= $#nums in your code, otherwise it skips 200 when 10 was entered).
#!/usr/bin/perl
use warnings;
use strict;
print "Enter an integer \n";
my $root = <>;
my #nums = (100 .. 200);
my $i = $#nums;
while ( $i >= 0 ) {
print "$nums[$i]\n" if $nums[$i] % $root == 0;
--$i;
}
There are more than a few ways to do it ... not all equally good:
#!/usr/bin/env perl
use strict;
use warnings;
run(#ARGV);
sub run {
my $root = $_[0] // get_root();
my #nums = (100 .. 200);
my #functions = (
sub {
my ($root, $nums) = #_;
my $i = #$nums;
while ($i--) {
print "$nums->[$i]\n" unless $nums->[$i] % $root;
}
return;
},
sub {
my ($root, $nums) = #_;
for my $n ( reverse #$nums ) {
print "$n\n" unless $n % $root;
}
return;
},
sub {
my ($root, $nums) = #_;
my $i;
while ($i++ < #$nums) {
print "$nums->[#$nums - $i]\n" unless $nums->[#$nums - $i] % $root;
}
return;
},
sub {
my ($root, $nums) = #_;
my #multiples = reverse grep !($_ % $root), #$nums;
print "$_\n" for #multiples;
return;
},
);
for my $i ( 0 ... $#functions ) {
print "=== Function $i ===\n";
$functions[$i]->($root, \#nums);
}
}
sub get_root {
return scalar <STDIN>;
}
print "Enter an integer \n";
my $root = <STDIN>;
my #nums = (100..200);
#nums = reverse #nums; #Just reverse the arrays
my $i = 0;
# code in while loop executes as long as condition is true
while ( $i < $#nums )
{
print "$nums[$i]\n",if($nums[$i] % $root == 0); $i++;
}
May be it will helps you.
for (my $i = $#nums; $i >= 0; --$i) { ... }
for (my $i = #nums; $i--; ) { ... }
for my $i (reverse 0 .. $#nums) { ... }
for (1 .. #nums) { my $i = -$_; ... } # Or: my $i = #nums-$_;
for my $num (reverse #nums) { ... }

stockholm to fasta format - include accession id in every header

Hello I've multiple sequences in stockholm format, at the top of every alignment there is a accession ID, for ex: '#=GF AC PF00406' and '//' --> this is the end of the alignment. When I'm converting the stockholm format to fasta format I need PF00406 in the header of every sequence of the particular alignment. Some times there will be multiple stockholm alignments in one file. I tried to modify the following perl script, it gave me bizarre results, any help will be greatly appreciated.
my $columns = 60;
my $gapped = 0;
my $progname = $0;
$progname =~ s/^.*?([^\/]+)$/$1/;
my $usage = "Usage: $progname [<Stockholm file(s)>]\n";
$usage .= " [-h] print this help message\n";
$usage .= " [-g] write gapped FASTA output\n";
$usage .= " [-s] sort sequences by name\n";
$usage .= " [-c <cols>] number of columns for FASTA output (default is $columns)\n";
# parse cmd-line opts
my #argv;
while (#ARGV) {
my $arg = shift;
if ($arg eq "-h") {
die $usage;
} elsif ($arg eq "-g") {
$gapped = 1;
} elsif ($arg eq "-s"){
$sorted = 1;
} elsif ($arg eq "-c") {
defined ($columns = shift) or die $usage;
} else {
push #argv, $arg;
}
}
#ARGV = #argv;
my %seq;
while (<>) {
next unless /\S/;
next if /^\s*\#/;
if (/^\s*\/\//) { printseq() }
else {
chomp;
my ($name, $seq) = split;
#seq =~ s/[\.\-]//g unless $gapped;
$seq{$name} .= $seq;
}
}
printseq();
sub printseq {
if($sorted){
foreach $key (sort keys %seq){
print ">$key\n";
for (my $i = 0; $i < length $seq{$key}; $i += $columns){
print substr($seq{$key}, $i, $columns), "\n";
}
}
} else{
while (my ($name, $seq) = each %seq) {
print ">$name\n";
for (my $i = 0; $i < length $seq; $i += $columns) {
print substr ($seq, $i, $columns), "\n";
}
}
}
%seq = ();
}
Depending on the how much variation there is in the line with the accessionID, you might need to modify the regex, but this works for your example file
my %seq;
my $aln;
while (<>) {
if ($_ =~ /#=GF AC (\w+)/) {
$aln = $1;
}
elsif ($_ =~ /^\s*\/\/\s*$/){
$aln = '';
}
next unless /\S/;
next if /^\s*\#/;
if (/^\s*\/\//) { printseq() }
else {
chomp;
my ($name, $seq) = split;
$name = $name . ' ' . $aln;
$seq{$name} .= $seq;
}
}
printseq();

Binary representation of float to decimal conversions in Perl

I read Stack Overflow question How do I convert a binary string to a number in Perl? on how to convert binary integers to decimal or vice versa in Perl. But how do I do this for float as well?
For example, conversion from 5.375 to 101.011 and vice versa.
sub number_to_binary_string {
my $in = shift;
my $sign = $in < 0 and $in = abs $in;
my $out = sprintf "%b.", int $in;
substr $out, 0, 0, '-' if $sign;
$in -= int $in;
do {
if ($in >= .5) {
$out .= '1';
$in -= .5;
}
else {
$out .= '0';
}
$in *= 2;
} while $in > 0;
return $out;
}
sub binary_string_to_number {
my $in = shift;
my ($int,$frac) = split /\./, $in;
my $sign = $int =~ s/^-//;
my $out = oct "0b$int";
my $mult = 1;
for my $digit (split //, $frac) {
$mult *= .5;
$out += $mult * $digit;
}
$out = -$out if $sign;
return $out;
}
Below is a machine- and build-specific implementation (NV = little-endian double).
It returns the number stored exactly, and it supports NaN, Infinity, -Infinity and -0 and subnormals. It trims leading zeros and trailing decimal zeroes.
sub double_to_bin {
my ($n) = #_;
my ($s, $e, $m) = unpack 'a a11 a52', unpack 'B64', "".reverse pack 'F', $n;
$s = $s ? '-' : '';
$e = oct("0b$e");
if ($e == 0x7ff) {
return ($m =~ /1/) ? 'NaN' : $s . 'Infinity'
} elsif ($e == 0x000) {
$m = "0$m"; $e -= 52;
} else {
$m = "1$m"; $e -= 1075;
}
if ($e >= 0) {
$m .= ('0' x $e);
} elsif ($e >= -52) {
substr($m, $e+53, 0, '.');
} else {
$m = '0.' . ('0' x (-$e-53)) . $m;
}
$m =~ s/^0+(?!\.)//;
$m =~ s/(?:\..*1\K|\.)0+\z//;
return $s . $m;
}
Here's a sketch of an interesting "portable" implementation. It doesn't handle any of the interesting edge-cases like integers, NaNs, infinities, or even negative numbers because I'm lazy, but extending it wouldn't be so hard.
(my $bin = sprintf "%b.%032b", int($num), 2**32 * ($num - int($num)))
=~ s/\.?0+$//;
The 2**32 seems like an architecture-specific magic number but in fact it's basically just how many bits of precision you want after the dot. Too small and you get harmless truncation; too large and there's potential for overflow (since %b probably casts to UV sometime before doing its formatting).
$TO_BIN = '-b';
$TO_DEC = '-d';
($op, $n ) = #ARGV;
die("USAGE: $0 -b <dec_to_convert> | -d <bin_to_convert>\n") unless ( $op =~ /^($TO_BIN|$TO_DEC)$/ && $n );
for (split(//,$n)) {
if ($_ eq ".") {
$f=".";
} else {
if (defined $f) { $f.=$_ } else { $i.=$_ }
}
}
$ci = sprintf("%b", $i) if $op eq $TO_BIN;
$ci = sprintf("%d", eval "0b$i") if $op eq $TO_DEC;
#f=split(//,$f) if $f;
if ($op eq $TO_BIN) {
while( $f && length($cf) < 16 ) {
($f *= 2) =~ s/(\d)(\.?.*)/$2/;
$cf .= $1 ? '1' : '0';
}
} else {
for ($i=1;$i<#f;$i++) {
$cf = ($cf + $f[#f-$i])/2;
}
}
$cf=~s/^.*\.|^/./ if $cf;
print("$ci$cf\n");