This is my script count.pl, I am trying to count the number of lines in a file.
The script's code :
chdir $filepath;
if (-e "$filepath"){
$total = `wc -l < file.list`;
printf "there are $total number of lines in file.list";
}
i can get a correct output, but i do not want to count blank lines and anything in the file that start with #. any idea ?
As this is a Perl program already open the file and read it, filtering out lines that don't count with
open my $fh, '<', $filename or die "Can't open $filename: $!";
my $num_lines = grep { not /^$|^\s*#/ } <$fh>;
where $filename is "file.list." If by "blank lines" you mean also lines with spaces only then chagne regex to /^\s*$|^\s*#/. See grep, and perlretut for regex used in its condition.
That filehandle $fh gets closed when the control exits the current scope, or add close $fh; after the file isn't needed for processing any more. Or, wrap it in a block with do
my $num_lines = do {
open my $fh, '<', $filename or die "Can't open $filename: $!";
grep { not /^$|^\s*#/ } <$fh>;
};
This makes sense doing if the sole purpose of opening that file is counting lines.
Another thing though: an operation like chdir should always be checked, and then there is no need for the race-sensitive if (-e $filepath) either. Altogether
# Perhaps save the old cwd first so to be able to return to it later
#my $old_cwd = Cwd::cwd;
chdir $filepath or die "Can't chdir to $filepath: $!";
open my $fh, '<', $filename or die "Can't open $filename: $!";
my $num_lines = grep { not /^$|^\s*#/ } <$fh>;
A couple of other notes:
There is no reason for printf. For all normal prints use say, for which you need use feature qw(say); at the beginning of the program. See feature pragma
Just in case, allow me to add: every program must have at the beginning
use warnings;
use strict;
Perhaps the original intent of the code in the question is to allow a program to try a non-existing location, and not die? In any case, one way to keep the -e test, as asked for
#my $old_cwd = Cwd::cwd;
chdir $filepath or warn "Can't chdir to $filepath: $!";
my $num_lines;
if (-e $filepath) {
open my $fh, '<', $filename or die "Can't open $filename: $!";
$num_lines = grep { not /^$|^\s*#/ } <$fh>;
}
where I still added a warning if chdir fails. Remove that if you really don't want it. I also added a declaration of the variable that is assigned the number of lines, with my $total_lines;. If it is declared earlier in your real code then of course remove that line here.
perl -ne '$n++ unless /^$|^#/ or eof; print "$n\n" if eof'
Works with multiple files too.
perl -ne '$n++ unless /^$|^#/ or eof; END {print "$n\n"}'
Better for a single file.
open(my $fh, '<', $filename);
my $n = 0;
for(<$fh>) { $n++ unless /^$|^#/}
print $n;
Using sed to filter out the "unwanted" lines in a single file:
sed '/^\s*#/d;/^\s*$/d' infile | wc -l
Obviously, you can also replace infile with a list of files.
The solution is very simple, no any magic.
use strict;
use warnings;
use feature 'say';
my $count = 0;
while( <> ) {
$count++ unless /^\s*$|^\s*#/;
}
say "Total $count lines";
Reference:
<>
My program is trying to search a string from multiple files in a directory. The code searches for single patterns like perl but fails to search a long string like Status Code 1.
Can you please let me know how to search for strings with multiple words?
#!/usr/bin/perl
my #list = `find /home/ad -type f -mtime -1`;
# printf("Lsit is $list[1]\n");
foreach (#list) {
# print("Now is : $_");
open(FILE, $_);
$_ = <FILE>;
close(FILE);
unless ($_ =~ /perl/) { # works, but fails to find string "Status Code 1"
print "found\n";
my $filename = 'report.txt';
open(my $fh, '>>', $filename) or die "Could not open file '$filename' $!";
say $fh "My first report generated by perl";
close $fh;
} # end unless
} # end For
There are a number of problems with your code
You must always use strict and use warnings at the top of every Perl program. There is little point in delcaring anything with my without strict in place
The lines returned by the find command will have a newline at the end which must be removed before Perl can find the files
You should use lexical file handles (my $fh instead of FILE) and the three-parameter form of open as you do with your output file
$_ = <FILE> reads only the first line of the file into $_
unless ($_ =~ /perl/) is inverted logic, and there's no need to specify $_ as it is the default. You should write if ( /perl/ )
You can't use say unless you have use feature 'say' at the top of your program (or use 5.010, which adds all features available in Perl v5.10)
It is also best to avoid using shell commands as Perl is more than able to do anything that you can using command line utilities. In this case -f $file is a test that returns true if the file is a plain file, and -M $file returns the (floating point) number of days since the file's modification time
This is how I would write your program
#!/usr/bin/perl
use strict;
use warnings;
use 5.010;
for my $file ( glob '/home/ad/*' ) {
next unless -f $file and int(-M $file) == 1;
open my $fh, '<', $file or die $!;
while ( <$fh> ) {
if ( /perl/ ) {
print "found\n";
my $filename = 'report.txt';
open my $out_fh, '>>', $filename or die "Could not open file '$filename': $!";
say $fh "My first report generated by perl";
close $out_fh;
last;
}
}
}
it should have matched unless $_ contains text in different case.
try this.
unless($_ =~ /Status\s+Code\s+1/i) {
Change
unless ($_ =~ /perl/) {
to:
unless ($_ =~ /(Status Code 1)/) {
I am certain the above works, except it's case sensitive.
Since you question it, I rewrote your script to make more sense of what you're trying to accomplish and implement the above suggestion. Correct me if I am wrong, but you're trying to make a script which matches "Status Code 1" in a bunch of files where last modified within 1 day and print the filename to a text file.
Anyways, below is what I recommend:
#!/usr/bin/perl
use strict;
use warnings;
my $output_file = 'report.txt';
my #list = `find /home/ad -type f -mtime -1`;
foreach my $filename (#list) {
print "PROCESSING: $filename";
open (INCOMING, "<$filename") || die "FATAL: Could not open '$filename' $!";
foreach my $line (<INCOMING>) {
if ($line =~ /(Status Code 1)/) {
open( FILE, ">>$output_file") or die "FATAL: Could not open '$output_file' $!";
print FILE sprintf ("%s\n", $filename);
close(FILE) || die "FATAL: Could not CLOSE '$output_file' $!";
# Bail when we get the first match
last;
}
}
close(INCOMING) || die "FATAL: Could not close '$filename' $!";
}
My code did not work for my any modifications. other than append nothing works for in open close functions.
#!/usr/local/bin/perl
my $file = 'test';
open(INFO, $file);
print INFO "Add this line please\n";
print INFO "First line\n";
close(INFO);
You need to tell perl what type of filehandle you want
open(INFO, ">", "$file")|| die "Cannot open $file";
This will create and write to a file.
Look up
http://perldoc.perl.org/functions/open.html
By default open(INFO, $file) will take the file handle in read mode('<') . So until unless you specify the write mode('>') you cannot print the values into the file . When you write the code you should use : use strict; and use warnings; which will be helpful.
Code:
use strict;
use warnings;
my $InputFile = $ARGV[0];
open(FH,'<',"$InputFile")or die "Couldn't open the file $InputFile: $!";
my #file_content = <FH>;
close(FH);
open(FH,'>',"$InputFile") or die "Cannot open $InputFile: $!";
#String to be added at the begining of the file
my $file = "test";
print FH $file . "\n";
print FH #file_content;
close(FH);
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) .....