could anyone please share with me a snippet where i can do a grep search in perl file. Example,
i need this grep: grep 1115852311 /opt/files/treated/postpaid/*
to be done in perl script and print all the matches
tried the below, but did not work :
my $start_dir= "\opt\files\treated\postpaid\";
my $file_name = "*";
my #filematches;
opendir(DIR, "$start_dir");
#xml_files = grep(1115852311,readdir(DIR));
print #xml_files;
A good start would be to read the documentation for grep(). If you do, you'll see that Perl's grep() works rather differently to the Unix grep command. The Unix command just looks for text in a list of files. The Perl version works on any list of data and returns any elements in that list for which an arbitrary Boolean expression is true.
A Perl version of the Unix command would look something like this:
while (<$some_open_filehandle>) {
print if /$some_string/;
}
That's not quite what you want, but we can use it as a start. First, let's write something that takes a filename and string and checks whether the string appears in the file:
sub is_string_in_file {
my ($filename, $string) = #_;
open my $fh, '<', $filename or die "Cannot open file '$filename': $!\n";
return grep { /$string/ } <$fh>;
}
We can now use that in a loop which uses readdir() to get a list of files.
my #files;
my $dir = '/opt/files/treated/postpaid/';
opendir my $dh, $dir or die $!;
while (my $file = readdir($dh)) {
if (is_string_in_file("$dir$file", 1115852311) {
push #files, "$dir$file";
}
}
After running that code, the list of files that contain your string will be in #files.
You might want to look at glob() instead of opendir() and readdir().
used the below snippet to achieve what i wanted
#!/usr/bin/perl
use strict;
use warnings;
sub is_string_in_file {
my ($filename, $string) = #_;
open my $fh, '<', $filename
or die "Cannot open file \n";
while(my $line = <$fh>){
if($line =~ /$string/){
print $string;
print $filename."\n";
}
}
#return grep { $_ eq $string } <$fh>;
}
my #files;
my $dir = '/opt/files/treated/postpaid/';
opendir my $dh, $dir or die $!;
while (my $file = readdir($dh)) {
is_string_in_file("$dir$file", 1115852311);
}
I have several monthly reports in csv format in a folder. The csv files all have 8 common columns (with headings) . Using perl, I would like to merge these files together line by line.
say
file 1:
1,2,3,4,5,6,7,8,
a1,b1,c1,d1,e1,f1,g1,h1,
a1,b1,c1,d1,e1,f1,g1,h1,
a1,b1,c1,d1,e1,f1,g1,h1,
file 2:
1,2,3,4,5,6,7,8,
a2,b2,c2,d2,e2,f2,g2,h2,
a2,b2,c2,d2,e2,f2,g2,h2,
a2,b2,c2,d2,e2,f2,g2,h2,
I would like the output to look something like that (join the rows and remove the headings)
output:
1,2,3,4,5,6,7,8,
a1,b1,c1,d1,e1,f1,g1,h1,
a1,b1,c1,d1,e1,f1,g1,h1,
a1,b1,c1,d1,e1,f1,g1,h1,
a2,b2,c2,d2,e2,f2,g2,h2,
a2,b2,c2,d2,e2,f2,g2,h2,
a2,b2,c2,d2,e2,f2,g2,h2,
I have managed to save the names of the files in an array. but for some reason, I could not join them.
can you please help me figure out what is wrong with my code. I am quite new to perl.
#! C:Strawberry/perl/bin;
use feature ':5.12';
use strict;
use warnings;
my $data_directory = 'R:/testing_data/';
opendir( DIR, $data_directory ) or die "Could not open $data_directory $!\n";
my #files = grep {/_monthlyreport\.csv$/} readdir(DIR); #to get on the monthly reports csv files
foreach my $file (#files) {
open( HANR, "<", '$data_directory' . my $files ) or die "cannot open $files: $!"; #read handler
open( HANW, ">>", "G:/outputfile_script.csv" ) or die "error $! \n"; #write handler for creating new sorted files
my #lines = ();
#lines = <HANR>;
foreach my $line (#lines) {
chomp($line);
my $count++;
next unless $count; # skip header i.e the first line containing stock details
print HANW join $line, "\n";
}
my $count = -1;
close(HANW);
close(HANR);
}
closedir(DIR);
exit 0;
Your open statement to your input filehandle is malformed, and my $count++; is also broken.
I'd also recommend modernizing your code by using lexical file handles. The following is a cleaned up version of your code:
use feature ':5.12';
use strict;
use warnings;
use autodie;
my $data_directory = 'R:/testing_data/';
opendir my $dh, "$data_directory";
open my $outfh, ">>", "G:/outputfile_script.csv";
my $seenheader = 0;
while (my $file = readdir $dh) {
next unless $file =~ /_monthlyreport\.csv$/;
open my $infh, '<', "$data_directory/$file";
while (<$infh>) {
print $outfh $_ if $. > 1 || ! $seenheader++;
}
}
This line is wrong.
open(HANR ,"<",'$data_directory'.my $files) or die "cannot open $files: $!";
Should be
open(HANR ,"<","$data_directory".$files) or die "cannot open $files: $!";
Add a counter and stop printing if the counter equals 0;
#! C:Strawberry/perl/bin;
use feature ':5.12';
use strict;
use warnings;
my $data_directory = 'R:/testing_data/';
opendir(DIR,$data_directory) or die "Could not open $data_directory $!\n";
my #files = grep {/_monthlyreport\.csv$/} readdir(DIR); #to get on the monthly reports csv files
foreach my $file (#files) {
open(HANR ,"<",'$data_directory'.my $files) or die "cannot open $files: $!"; #read handler
open(HANW , ">>","G:/outputfile_script.csv") or die "error $! \n"; #write handler for creating new sorted files
my #lines=();
#lines=<HANR>;
my $i =0;
foreach my $line (#lines){
next if ($i==0) ;
chomp ($line) ;
my $count++;
next unless $count; # skip header i.e the first line containing stock details
print HANW join $line,"\n";
}
my $count= -1;
close(HANW);
close(HANR);
}
closedir(DIR);
exit 0;
At the moment this code replaces all occurences of my matching string with my replacement string, but only for the file I specify on the command line. Is there a way to change this so that all .txt files for example, in the same directory (the directory I specify) are processed without having to run this 100s of times on individual files?
#!/usr/bin/perl
use warnings;
my $filename = $ARGV[0];
open(INFILE, "<", $filename) or die "Cannot open $ARGV[0]";
my(#fcont) = <INFILE>;
close INFILE;
open(FOUT,">$filename") || die("Cannot Open File");
foreach $line (#fcont) {
$line =~ s/\<br\/\>\n([[:space:]][[:space:]][[:space:]][[:space:]][A-Z])/\n$1/gm;
print FOUT $line;
}
close INFILE;
I have also tried this:
perl -p0007i -e 's/\<br\/\>\n([[:space:]][[:space:]][[:space:]][[:space:]][A-Z])/\n$1/m' *.txt
But have noticed that is only changes the first occurence of the matched pattern and ignores all the rest in the file.
I also have tried this, but it doesn't work in the sense that it just creates a blank file:
use v5.14;
use strict;
use warnings;
use DBI;
my $source_dir = "C:/Testing2";
# Store the handle in a variable.
opendir my $dirh, $source_dir or die "Unable to open directory: $!";
my #files = grep /\.txt$/i, readdir $dirh;
closedir $dirh;
# Stop script if there aren't any files in the list
die "No files found in $source_dir" unless #files;
foreach my $file (#files) {
say "Processing $source_dir/$file";
open my $in, '<', "$source_dir/$file" or die "Unable to open $source_dir/$file: $!\n";
open(FOUT,">$source_dir/$file") || die("Cannot Open File");
foreach my $line (#files) {
$line =~ s/\<br\/\>\n([[:space:]][[:space:]][[:space:]][[:space:]][A-Z])/\n$1/gm;
print FOUT $line;
}
close $in;
}
say "Status: Processing of complete";
Just wondering what am I missing from my code above? Thanks.
You could try the following:
opendir(DIR,"your_directory");
my #all_files = readdir(DIR);
closedir(DIR);
for (#all_files) .....
I have to files like A.ini and B.ini ,I want to merge both the files in A.ini
examples of files:
A.ini::
a=123
b=xyx
c=434
B.ini contains:
a=abc
m=shank
n=paul
my output in files A.ini should be like
a=123abc
b=xyx
c=434
m=shank
n=paul
I want to this merging to be done in perl language and I want to keep the copy of old A.ini file at some other place to use old copy
A command line variant:
perl -lne '
($a, $b) = split /=/;
$v{$a} = $v{$a} ? $v{$a} . $b : $_;
END {
print $v{$_} for sort keys %v
}' A.ini B.ini >NEW.ini
How about:
#!/usr/bin/perl
use strict;
use warnings;
my %out;
my $file = 'path/to/A.ini';
open my $fh, '<', $file or die "unable to open '$file' for reading: $!";
while(<$fh>) {
chomp;
my ($key, $val) = split /=/;
$out{$key} = $val;
}
close $fh;
$file = 'path/to/B.ini';
open my $fh, '<', $file or die "unable to open '$file' for reading: $!";
while(<$fh>) {
chomp;
my ($key, $val) = split /=/;
if (exists $out{$key}) {
$out{$key} .= $val;
} else {
$out{$key} = $val;
}
}
close $fh;
$file = 'path/to/A.ini';
open my $fh, '>', $file or die "unable to open '$file' for writing: $!";
foreach(keys %out) {
print $fh $_,'=',$out{$_},"\n";
}
close $fh;
The two files to be merged can be read in a single pass and don't need to be treated as separate source files. That allows the use of <> to read all files passed as parameters on the command line.
Keeping a backup copy of A.ini is simply a matter of renaming it before writing the merged data to a new file of the same name.
This program appears to do what you need.
use strict;
use warnings;
my $file_a = $ARGV[0];
my (#keys, %values);
while (<>) {
if (/\A\s*(.+?)\s*=\s*(.+?)\s*\z/) {
push #keys, $1 unless exists $values{$1};
$values{$1} .= $2;
}
}
rename $file_a, "$file_a.bak" or die qq(Unable to rename "$file_a": $!);
open my $fh, '>', $file_a or die qq(Unable to open "$file_a" for output: $!);
printf $fh "%s=%s\n", $_, $values{$_} for #keys;
output (in A.ini)
a=123abc
b=xyx
c=434
m=shank
n=paul
use strict;
my #array=('f1','f2','f3');
my $dir ='\tmp';
foreach (#array) {
my $FH = $_;
open ("$FH", ">$dir/${FH}.txt") or die $!;
}
foreach (#array) {
my $FH = $_;
close($FH);
}
i got "Can't use string ("f1") as a symbol ref while "strict refs" in use at bbb.pl line 6." error . What is the isuse ?
First: 2 arg open is bad, 3 arg open is better.
open( .. , ">", "$dir/${FN}.txt")
second, what on earth are you doing with open("$FH" ..
argument 1 to open is supposed to be an actual filehandle of sorts which can be connected to a datastream. passing it a string will not work.
INSANE: open( "Hello world", .... ) # how can we open hello world, its not a file handle
WORKS: open( *FH,.... ) # but don't do this, globs are package-globals and pesky
BEST: open( my $fh, .... ) # and they close themself when $fh goes out of scope!
third
foreach my $filename ( #ARRAY ){
}
Forth:
dir = \tmp ? are you sure? I think you meant /tmp , \tmp is something different altogether.
Fifth:
use warnings;
using strict is good, but you should use warnings too.
Sixth: Use names for variables that are explanatory, we know # is an array #array is not more helpful.
ALL TOGETHER
use strict;
use warnings;
my #filenames=('f1','f2','f3');
my #filehandles = ();
my $dir ='/tmp';
foreach my $filename (#filenames) {
open (my $fh,'>', "${dir}/${filename}.txt") or die $!;
push #filehandles, $fh;
}
# some code here, ie:
foreach my $filehandle ( #filehandles ) {
print {$filehandle} "Hello world!";
}
# and then were done, cleanup time
foreach my $filehandle ( #filehandles ){
close $filehandle or warn "Closing a filehandle didn't work, $!";
}
Alternatively, depending on what you were trying to do, this may have been better code:
use strict;
use warnings;
my #filenames=('f1','f2','f3');
my $dir ='/tmp';
foreach my $filename (#filenames) {
open (my $fh,'>', "${dir}/${filename}.txt") or die $!;
print {$fh} "Hello world!";
}
I don't explicitly close $fh, because its not needed, as soon as $fh goes out of scope ( at the end of the block in this case ) it is closed automatically.
You are using a string "f1" as the first argument to open which expects a filehandle.
You probably wanted to do:
my #filehandles = (); # Stash filehandles there so as to not lose filenames
foreach (#array) {
my $FH = $_;
open (my $fh, ">", "$dir/${FH}.txt") or die $!;
push #filehandles, $fh;
}