I have a file that I want to read it and for each 'word' found to delete the next 2 lines including the line with the 'word'.
the structure of the file is somekind line this:
1
2
3
word
321
3213
412
word
132
1231
this is what I have until now:
open FILE, "$localDir\\x.txt" or die $!;
#fileLines = <FILE>;
close FILE;
$output = 'y.txt';
open my $outfile, '>', $output or die "Can't write to $output: $!";
for ($i = 0; $i < scalar(#fileLines); $i++) {
next if ($fileLines[$i] =~ /'word/);
print $outfile $_ ;
}
thanks
I'd do it something like this:
#!/usr/bin/env perl
use strict;
use warnings;
#iterate one line at a time.
while ( <DATA> ) {
#if we hit the delimiter, read and discard two more line.
if ( m/word/ ) { <DATA>; <DATA> ; }
#otherwise print it.
else { print; };
}
__DATA__
1
2
3
word
321
3213
412
word
132
1231
Which gives:
1
2
3
412
The excellent Tie::File module often seems to be forgotten. It is ideal for this sort of thing
use strict;
use warnings;
use File::Copy qw/ copy /;
use Tie::File;
my $local_dir = '.';
copy "$local_dir/x.txt", 'y.txt';
tie my #file, 'Tie::File', 'y.txt';
for ( my $i = 0; $i < #file; ) {
if ( $file[$i] eq 'word' ) {
splice #file, $i, 3;
}
else {
++$i;
}
}
output
1
2
3
412
Related
The script is printing the amount of input lines, I want it to print the amount of input lines that are present in another file
#!/usr/bin/perl -w
open("file", "text.txt");
#todd = <file>;
close "file";
while(<>){
if( grep( /^$_$/, #todd)){
#if( grep #todd, /^$_$/){
print $_;
}
print "\n";
}
if for example file contains
1
3
4
5
7
and the input file that will be read from contains
1
2
3
4
5
6
7
8
9
I would want it to print 1,3,4,5 and 7
but 1-9 are being printed instead
UPDATE******
This is my code now and I am getting this error
readline() on closed filehandle todd at ./may6test.pl line 3.
#!/usr/bin/perl -w
open("todd", "<text.txt");
#files = <todd>; #file looking into
close "todd";
while( my $line = <> ){
chomp $line;
if ( grep( /^$line$/, #files) ) {
print $_;
}
print "\n";
}
which makes no sense to me because I have this other script that is basically doing the same thing
#!/usr/bin/perl -w
open("file", "<text2.txt"); #
#file = <file>; #file looking into
close "file"; #
while(<>){
$temp = $_;
$temp =~ tr/|/\t/; #puts tab between name and id
my ($name, $number1, $number2) = split("\t", $temp);
if ( grep( /^$number1$/, #file) ) {
print $_;
}
}
print "\n";
OK, the problem here is - grep sets $_ too. So grep { $_ } #array will always give you every element in the array.
At a basic level - you need to:
while ( my $line = <> ) {
chomp $line;
if ( grep { /^$line$/ } #todd ) {
#do something
}
}
But I'd suggest instead that you might want to consider building a hash of your lines instead:
open( my $input, '<', "text.txt" ) or die $!;
my %in_todd = map { $_ => 1 } <$input>;
close $input;
while (<>) {
print if $in_todd{$_};
}
Note - you might want to watch for trailing linefeeds.
What this program is meant to do is that it reads a text file which looks like:
Item \t\t Price
apple \t\t 20
orange \t\t 50
lime \t\t 30
I'm using split function to split these 2 columns and then i should apply a -25% discount on all items and print it out to a new file. My code so far does what i want but the new text file has a '0' value under my last number in price column. I also get 2 errors if i run it with "use warnings" which are:
Use of uninitialized value $item in multiplication * ...
Use of uninitialized value $item[0] in concatenation (.) ...
I should also tell total number of items calculated but i get like 5 1's instead of 5. (11111 instead of 5)
use strict;
use warnings;
my $filename = 'shop.txt';
if (-e $filename){
open (IN, $filename);
}
else{
die "Can't open input file for reading: $!";
}
open (OUT,">","discount.txt") or die "Can't open output file for writing: $!";
my $header = <IN>;
print OUT $header;
while (<IN>) {
chomp;
my #items = split(/\t\t/);
foreach my $item ($items[1]){
my $discount = $item * (0.75);
print OUT "$items[0]\t\t$discount\n";
}
}
This is too complicated and not clear what are you doing in foreach loop and you are not skipping empty lines. Keep it simple:
use warnings;
use strict;
use v5.10;
<>; # skip header
while(my $line = <>)
{
chomp $line;
next unless ($line);
my ($title, $price ) = split /\s+/, $line;
if( $title && defined $price )
{
$price *= 0.75;
say "$title\t\t$price";
}
}
and run like
perl script.pl <input.txt >output.txt
use strict;
use warnings;
my $filename = 'shop.txt';
if (-e $filename){
open (IN, $filename);
}
else{
die "Can't open input file for reading: $!";
}
open (OUT,">","discount.txt") or die "Can't open output file for writing: $!";
my $header = <IN>;
my $item;
my $price;
print OUT $header;
while (<IN>) {
chomp;
($item, $price) = split(/\t\t/);
my $discount = $price*0.75;
print OUT "$item $discount\n";
}
This should help! :)
If the total item count isn't very important to you:
$ perl -wane '$F[1] *= 0.75 if $. > 1; print join("\t", #F), "\n";' input.txt
Output:
Item Price
apple 15
orange 37.5
lime 22.5
If you really need the total item count:
$ perl -we 'while (<>) { #F = split; if ($. > 1) { $F[1] *= 0.75; $i++ } print join("\t", #F), "\n"; } print "$i items\n";' input.txt
Output:
Item Price
apple 15
orange 37.5
lime 22.5
3 items
I'd use this approach
#!/usr/bin/perl
use strict;
use warnings;
my %items;
my $filename = 'shop.txt';
my $discount = 'discount.txt';
open my $in, '<', $filename or die "Failed to open file! : $!\n";
open my $out, ">", $discount or die "Can't open output file for writing: $!";
print $out "Item\t\tPrice\n";
my $cnt = 0;
while (my $line = <$in>) {
chomp $line;
if (my ($item,$price) = $line =~ /(\w.+)\s+([0-9.]+)/){
$price = $price * (0.75);
print $out "$item\t\t$price\n";
$items{$item} = $price;
$cnt++;
}
}
close($in);
close($out);
my $total = keys %items;
print "Total items - $total \n";
print "Total items - $cnt\n";
Using regex capture groups to capture the item and price (using \w.+ in case the item is 2 words like apple sauce), this will also prevent empty lines from printing to file.
I also hard coded the Item and Price header, probably a good idea if you are going to be using a consistent header.
Hope it helps
---Update ----
I added 2 examples of a total count in my script. The first one is using a hash and printing out the hash size, the second method is using a counter. The hash option is good except if your list has 2 items that are the same in which case the key of the hash will be overridden with the last item found which shares the same name. The counter is a simple solution.
I am trying to bring a file loop through it and remove any strings that have less than four characters in it and then print the list. I come from a javascript world and perl is brand new to me.
use strict;
use warnings;
sub lessThan4 {
open( FILE, "<names.txt" );
my #LINES = <FILE>;
close( FILE );
open( FILE, ">names.txt" );
foreach my $LINE ( #LINES ) {
print FILE $LINE unless ( $LINE.length() < 4 );
}
close( FILE );
}
use strict;
use warnings;
# automatically throw exception if open() fails
use autodie;
sub lessThan4 {
my #LINES = do {
# modern perl uses lexical, and three arg open
open(my $FILE, "<", "names.txt");
<$FILE>;
};
# remove newlines
chomp(#LINES);
open(my $FILE, ">", "names.txt");
foreach my $LINE ( #LINES ) {
print $FILE "$LINE\n" unless length($LINE) < 4;
# possible alternative to 'unless'
# print $FILE "$LINE\n" if length($LINE) >= 4;
}
close($FILE);
}
You're basically there. I hope you'll find some comments on your code useful.
# Well done for including these. So many new Perl users don't
use strict;
use warnings;
# Perl programs traditionally use all lower-case subroutine names
sub lessThan4 {
# 1/ You should use lexical variables for filehandles
# 2/ You should use the three-argument version of open()
# 3/ You should always check the return value from open()
open( FILE, "<names.txt" );
# Upper-case variable names in Perl are assumed to be global variables.
# This is a lexical variable, so name it using lower case.
my #LINES = <FILE>;
close( FILE );
# Same problems with open() here.
open( FILE, ">names.txt" );
foreach my $LINE ( #LINES ) {
# This is your biggest problem. Perl doesn't yet embrace the idea of
# calling methods to get properties of a variable. You need to call
# length() as a function.
print FILE $LINE unless ( $LINE.length() < 4 );
}
close( FILE );
}
Rewriting to take all that into account, we get the following:
use strict;
use warnings;
sub less_than_4 {
open( my $in_file_h, '<', 'names.txt' ) or die "Can't open file: $!";
my #lines = <$in_file_h>;
close( $in_file_h );
open( my $out_file_h, '>', 'names.txt' ) or die "Can't open file: $!";
foreach my $line ( #lines ) {
# Note: $line will include the newline character, so you might need
# to increase 4 to 5 here
print $out_file_h $line unless length $line < 4;
}
close( $out_file_h );
}
I am trying to bring a file loop through it and remove any strings that have less than four characters in it and then print the list.
I suppose you need to remove strings from the file which are less than 4 chars in length.
#!/usr/bin/perl
use strict;
use warnings;
open ($FH, "<", "names.txt");
my #final_list;
while (my $line = <$FH>) {
map {
length($_) > 4 and push (#final_list, $_) ;
} split (/\s/, $line);
}
print "\nWords with more than 4 chars: #final_list\n";
#Please try this one:
use strict;
use warnings;
my #new;
while(<DATA>)
{
#Push all the values less than 4 characters
push(#new, $_) unless(length($_) > '4');
}
print #new;
__DATA__
Williams
John
Joe
Lee
Albert
Francis
Sun
File 1 has ranges 3-9, 2-6 etc
3 9
2 6
12 20
File2 has values: column 1 indicates the range and column 2 has values.
1 4
2 4
3 5
4 4
5 4
6 1
7 1
8 1
9 4
I would like to calculate the sum of values (file2, column2) for ranges in file1). Eg: If range is 3-9, then sum of values will be 5+4+4+1+1+1+4 = 20
What I have tried is:
open (FILE1,"file1.txt");
open (FILE2,"file2.txt");
#file1 = <FILE1>;
#file2 = <FILE2>;
foreach (#file1)
{
#split_file2 = split("\\s",$_); //splitting the file by space
foreach (#file2)
{
#split_file2 = split("\\s",$_); //splitting the file by space
if (#split_file1[0] == #split_file2[0]) //if column0 of file1 matches with column0 of file2
{
$x += #split_file2[1]; //sum the column1 of file2
if ( #split_file2[0] == #split_file1[0] ) //until column1 of file1 = column0 of file2.
{
last;
}
}
}}
Always use use strict; use warnings;.
split /\s/ is easier to read. split ' ' is what you actually want.
Don't use global variables (e.g. for file handles).
It's useful to check if open succeeds, if only by adding or die $!.
Use meaningful names, not file1 and file2.
use strict;
use warnings;
use feature qw( say );
use List::Util qw( sum );
my $file1 = 'file1.txt';
my $file2 = 'file2.txt';
my #file2;
{
open(my $fh, '<', $file2)
or die "Can't open $file2: $!\n";
while (<$fh>) {
my ($k, $v) = split;
$file2[$k] = $v;
}
}
{
open(my $fh, '<', $file1)
or die "Can't open $file1: $!\n";
while (<$fh>) {
my ($start, $end) = split;
say sum grep defined, #file2[$start .. $end];
}
}
Another solution:
#!/usr/bin/perl
use strict;
use warnings;
my $f1 = shift;
my $f2 = shift;
open FH1, "<", $f1 or die "$!\n";
open FH2, "<", $f2 or die "$!\n";
my %data;
while (<FH1>) {
$data{$1} = $2 if ($_ =~ m/^(\d+)\s+(\d+)$/);
}
while (<FH2>) {
if ($_ =~ m/^(\d+)\s+(\d+)$/) {
my $sum;
for ($1..$2) {
$sum += $data{$_} if defined($data{$_});
}
print "sum for $1-$2: $sum\n" if defined($sum);
}
}
close FH1;
close FH2;
Call: script.pl values.txt ranges.txt
I'm trying to find the line of first occurrence of the string "victory" in each txt file in a folder. For each first "victory" in file I would like to save the number from that line to #num and the file name to #filename
Example: For the file a.txt that starts with the line: "lalala victory 123456" -> $num[$i]=123456 and $filename[$i]="a.txt"
ARGV holds all the file names. my problem is that I'm trying to go line by line and I don't know what I'm doing wrong.
one more thing - how can I get the last occurrence of "victory" in the last file??
use strict;
use warnings;
use File::Find;
my $dir = "D:/New folder";
find(sub { if (-f && /\.txt$/) { push #ARGV, $File::Find::name } }, $dir); $^I = ".bak";
my $argvv;
my $counter=0;
my $prev_arg=0;
my $line = 0;
my #filename=0;
my #num=0;
my $i = 0;
foreach $argvv (#ARGV)
{
#open $line, $argvv or die "Could not open file: $!";
my $line = IN
while (<$line>)
{
if (/victory/)
{
$line = s/[^0-9]//g;
$first_bit[$i] = $line;
$filename[$i]=$argvv;
$i++;
last;
}
}
close $line;
}
for ($i=0; $i<3; $i++)
{
print $filename[$i]." ".$num[$i]."\n";
}
Thank you very much! :)
Your example script has a number of minor problems. The following example should do what you want in a fairly clean manner:
#!/usr/bin/perl
use strict;
use warnings;
use File::Find;
# Find the files we're interested in parsing
my #files = ();
my $dir = "D:/New folder";
find(sub { if (-f && /\.txt$/) { push #files, $File::Find::name } }, $dir);
# We'll store our results in a hash, rather than in 2 arrays as you did
my %foundItems = ();
foreach my $file (#files)
{
# Using a lexical file handle is the recommended way to open files
open my $in, '<', $file or die "Could not open $file: $!";
while (<$in>)
{
# Uncomment the next two lines to see what's being parsed
# chomp; # Not required, but helpful for the debug print below
# print "$_\n"; # Print out the line being parsed; for debugging
# Capture the number if we find the word 'victory'
# This assumes the number is immediately after the word; if that
# is not the case, it's up to you to modify the logic here
if (m/victory\s+(\d+)/)
{
$foundItems{$file} = $1; # Store the item
last;
}
}
close $in;
}
foreach my $file (sort keys %foundItems)
{
print "$file=> $foundItems{$file}\n";
}
the below searches for a string abc in all the files(file*.txt) and prints only the first line.
perl -lne 'BEGIN{$flag=1}if(/abc/ && $flag){print $_;$flag=0}if(eof){$flag=1}' file*.txt
tested:
> cat temp
abc 11
22
13
,,
abc 22
bb
cc
,,
ww
kk
ll
,,
> cat temp2
abc t goes into 1000
fileA1, act that abc specific place
> perl -lne 'BEGIN{$flag=1}if(/abc/ && $flag){print $_;$flag=0}if(eof){$flag=1}' temp temp2
abc 11
abc t goes into 1000
>