I have a huge file which consists of similar lines below , with different clocks:
cmd -quiet [get_ports p1] ref_clocks "cudtclk_sp cudtclk"
cmd -quiet [get_ports p2] clock "cu2xdtclk_sp cu2xdtclk"
And I need to replace cudtclk with some other name like cdtclk whenever I have ref_clocks in my file, globally.
I have written following code but it doesn't seem to be working.
#!/usr/bin/perl
use strict;
use warnings;
sub clock_change
{ # Get the subroutine's argument.
my $arg = shift;
# Hash of stuff we want to replace.
my %replace = (
"cudtclk" => "cdtclk",
);
# See if there's a replacement for the given text.
my $text = $replace{$arg};
if(defined($text)) {
return $text;
}
return $arg;
}
open PAR, "<file name>";
while(<PAR>) {
$_ =~ s/\S+\s\S+\s\S+\s\S+\sref_clocks\s+(\S+\s+\S+)/clock_change($1)/eig;
print $_; ##print it to some file later.
}
"And I need to replace cudtclk with some other name like cdtclk"
perl -pe 's/\bcudtclk\b/cdtclk/' thefile > newfile
"whenever I have ref_clocks"
perl -pe 's/\bcudtclk\b/cdtclk/ if /\bref_clocks\b/' thefile > newfile
Alternatively:
# saves original file as file.bak
perl -i.bak -pe 's/\bcudtclk\b/cdtclk/ if /\bref_clocks\b/' file
Tighten to suit your data, as necessary.
Although the substitution seems like unnecessarily complex, you can fix it with something similar to:
$_ =~ s/(ref_clocks\s+")([^_]+)_sp(\s+)\2/
$1.clock_change($2)."_sp$3".clock_change($2)/eig;
Related
I'm new in Perl, so it's maybe a very basic case that i still can't understand.
Case:
Program tell user to types the file name.
User types the file name (1 or more files).
Program read the content of file input.
If it's single file input, then it just prints the entire content of it.
if it's multi files input, then it combines the contents of each file in a sequence.
And then print result to a temporary new file, which located in the same directory with the program.pl .
file1.txt:
head
a
b
end
file2.txt:
head
c
d
e
f
end
SINGLE INPUT program ioSingle.pl:
#!/usr/bin/perl
print "File name: ";
$userinput = <STDIN>; chomp ($userinput);
#read content from input file
open ("FILEINPUT", $userinput) or die ("can't open file");
#PRINT CONTENT selama ada di file tsb
while (<FILEINPUT>) {
print ; }
close FILEINPUT;
SINGLE RESULT in cmd:
>perl ioSingle.pl
File name: file1.txt
head
a
b
end
I found tutorial code that combine content from multifiles input but cannot adapt the while argument to code above:
while ($userinput = <>) {
print ($userinput);
}
I was stucked at making it work for multifiles input,
How am i suppose to reformat the code so my program could give result like this?
EXPECTED MULTIFILES RESULT in cmd:
>perl ioMulti.pl
File name: file1.txt file2.txt
head
a
b
end
head
c
d
e
f
end
i appreciate your response :)
A good way to start working on a problem like this, is to break it down into smaller sections.
Your problem seems to break down to this:
get a list of filenames
for each file in the list
display the file contents
So think about writing subroutines that do each of these tasks. You already have something like a subroutine to display the contents of the file.
sub display_file_contents {
# filename is the first (and only argument) to the sub
my $filename = shift;
# Use lexical filehandl and three-arg open
open my $filehandle, '<', $filename or die $!;
# Shorter version of your code
print while <$filehandle>;
}
The next task is to get our list of files. You already have some of that too.
sub get_list_of_files {
print 'File name(s): ';
my $files = <STDIN>;
chomp $files;
# We might have more than one filename. Need to split input.
# Assume filenames are separated by whitespace
# (Might need to revisit that assumption - filenames can contain spaces!)
my #filenames = split /\s+/, $files;
return #filenames;
}
We can then put all of that together in the main program.
#!/usr/bin/perl
use strict;
use warnings;
my #list_of_files = get_list_of_files();
foreach my $file (#list_of_files) {
display_file_contents($file);
}
By breaking the task down into smaller tasks, each one becomes easier to deal with. And you don't need to carry the complexity of the whole program in you head at one time.
p.s. But like JRFerguson says, taking the list of files as command line parameters would make this far simpler.
The easy way is to use the diamond operator <> to open and read the files specified on the command line. This would achieve your objective:
while (<>) {
chomp;
print "$_\n";
}
Thus: ioSingle.pl file1.txt file2.txt
If this is the sole objective, you can reduce this to a command line script using the -p or -n switch like:
perl -pe '1' file1.txt file2.txt
perl -ne 'print' file1.txt file2.txt
These switches create implicit loops around the -e commands. The -p switch prints $_ after every loop as if you had written:
LINE:
while (<>) {
# your code...
} continue {
print;
}
Using -n creates:
LINE:
while (<>) {
# your code...
}
Thus, -p adds an implicit print statement.
I have a series of strings and their replacements separated by spaces:
a123 b312
c345 d453
I'd like to replace those strings in the left column with those in the right column, and undo the replacements later on. For the first part I could construct a sed command s/.../...;s/.../... but that doesn't consider reversing, and it requires me to significantly alter the input, which takes time. Is there a convenient way to do this?
Listed some example programs, could be anything free for win/lin.
Text editors provide "undo" functionality, but command-line utilities don't. You can write a script to do the replacement, then reverse the replacements file to do the same thing in reverse.
Here's a script that takes a series of replacements in 'replacements.txt' and runs them against the script's input:
#!/usr/bin/perl -w
use strict;
open REPL, "<replacements.txt";
my #replacements;
while (<REPL>) {
chomp;
push #replacements, [ split ];
}
close REPL;
while (<>) {
for my $r (#replacements) { s/$r->[0]/$r->[1]/g }
print;
}
If you save this file as 'repl.pl', and you save your file above as 'replacements.txt', you can use it like this:
perl repl.pl input.txt >output.txt
To convert your replacements file into a 'reverse-replacements.txt' file, you can use a simple awk command:
awk '{ print $2, $1 }' replacements.txt >reverse-replacements.txt
Then just modify the Perl script to use the reverse replacements file instead of the forward one.
use strict;
use warnings;
unless (#ARGV == 3) {
print "Usage: script.pl <reverse_changes?> <rfile> <input>\n";
exit;
}
my $reverse_changes = shift;
my $rfile = shift;
open my $fh, "<", $rfile or die $!;
my %reps = map split, <$fh>;
if ($reverse_changes) {
%reps = reverse %reps;
}
my $rx = join "|", keys %reps;
while (<>) {
s/\b($rx)\b/$reps{$1}/g;
print;
}
The word boundary checks \b surrounding the replacements will prevent partial matches, e.g. replacing a12345 with b31245. In the $rx you may wish to escape meta characters, if such can be present in your replacements.
Usage:
To perform the replacements:
script.pl 0 replace.txt input.txt > output.txt
To reverse changes:
script.pl 1 replace.txt output.txt > output2.txt
I am getting the an error while reading a file and below is the script.
#!/bin/bash
$file = "SampleLogFile.txt"; #--- line 2
open(MYINPUTFILE,$file); #--- line 3
while(<**MYINPUTFILE**>) {
# Good practice to store $_ value because
# subsequent operations may change it.
my($line) = $_;
# Good practice to always strip the trailing
# newline from the line.
chomp($line);
# Convert the line to upper case.
print "$line" if $line = ~ /sent/;
}
close (MYINPUTFILE);
Output :
PerlTesting_New.ksh[2]: =: not found
PerlTesting_New.ksh[3]: syntax error at line 3 : `(' unexpected
Any idea what the issue is ?
Change
#!/bin/bash
to
#!/usr/bin/perl
Otherwise Perl will not be interpreting your script. Change path accordingly as per your system
Okay, whoever is teaching you to write Perl like this needs to move out of the nineties.
#!/usr/bin/perl
use strict; # ALWAYS
use warnings; # Also always.
# When you learn more you can selectively turn off bits of strict and warnings
# functionality on an as needed basis.
use IO::File; # A nice OO module for working with files.
my $file_name = "SampleLogFile.txt"; # note that we have to declare $file now.
my $input_fh = IO::File->new( $file_name, '<' ); # Open the file read-only using IO::File.
# You can avoid assignment through $_ by assigning to a variable, even when you use <$fh>
while( my $line = $input_fh->getline() ) {
# chomp($line); # Chomping is usually a good idea.
# In this case it does nothing but screw up
# your output, so I commented it out.
# This does nothing of the sort:
# Convert the line to upper case.
print "$line" if $line = ~ /sent/;
}
You can also do this with a one liner:
perl -pe '$_ = "" unless /sent/;' SampleLogFile.txt
See perlrun for more info on one-liners.
hmm, your first line : #!/bin/bash
/bin/bash : This is the Bash shell.
You may need to change to
!/usr/bin/perl
My test file has "n" number of lines and between each line there is a ^M, which in turn makes it one big string. The code I am working with opens said file and should parse out a header and then the subsequent rows, then searches for the Directory Path and File name. But because the file just ends up as a big string it doesn't work correctly
#!/usr/bin/perl
#use strict;
#use warnings;
open (DATA, "<file.txt") or die ("Unable to open file");
my $search_string = "Directory Path";
my $column_search = "Filename";
my $header = <DATA>;
my #header_titles = split /\t/, $header;
my $extract_col = 0;
my $col_search = 0;
for my $header_line (#header_titles) {
last if $header_line =~ m/$search_string/;
$extract_col++;
}
for my $header_line (#header_titles) {
last if $header_line =~m/$column_search/;
$col_search++;
}
print "Extracting column $extract_col $search_string\n";
while ( my $row = <DATA> ) {
last unless $row =~ /\S/;
chomp $row;
my #cells = split /\t/, $row;
$cells[74]=~s/:/\//g;
$cells[$extract_col]= $cells[74] . $cells[$col_search];
print "$cells[$extract_col] \n";
}
When i open the test file in VI i have used
:%s/^M/\r/g
and that removes the ^M's but how do i do it inside this perl program? When i tried a test program and inserted that s\^M/\r/g and had it write to a different file it came up as a lot of Chinese characters.
If mac2unix isn't working for you, you can write your own mac2unix as a Perl one-liner:
perl -pi -e 'tr/\r/\n/' file.txt
That will likely fail if the size of the file is larger than virtual memory though, as it reads the whole file into memory.
For completeness, let's also have a dos2unix:
perl -pi -e 'tr/\r//d' file.txt
and a unix2dos:
perl -pi -e 's/\n/\r\n/g' file.txt
Before you start reading the file, set $/ to "\r". This is set to the linefeed character by default, which is fine for UNIX-style line endings, and almost OK for DOS-style line endings, but useless for the old Mac-style line endings you are seeing. You can also try mac2unix on your input file if you have it installed.
For more, look for "INPUT_RECORD_SEPARATOR" in the perlvar manpage.
Did this file originate on a windows system? If so, try running the dos2unix command on the file before reading it. You can do this before invoking the perl script or inside the script before you read it.
You might want to set $\ (input record separator) to ^M in the beginning of your script, such as:
$\ = "^M";
perl -MExtUtils::Command -e dos2unix file
I have this part of a code for editing cue sheets and I don't know how to reverse two consecutive lines if found:
/^TITLE.*?"$/
/^PERFORMER.*?"$/
to reverse to
/^PERFORMER.*?"$/
/^TITLE.*?"$/
What would it be the solution in my case?
use strict;
use warnings;
use File::Find;
use Tie::File;
my $dir_target = 'test';
find(\&c, $dir_target);
sub c {
/\.cue$/ or return;
my $fn = $File::Find::name;
tie my #lines, 'Tie::File', $fn or die "could not tie file: $!";
for (my $i = 0; $i < #lines; $i++) {
if ($lines[$i] =~ /^REM (DATE|GENRE|REPLAYGAIN).*?$/) {
splice(#lines, $i, 3);
}
if ($lines[$i] =~ /^\s+REPLAYGAIN.*?$/) {
splice(#lines, $i, 1);
}
}
untie #lines;
}
This may seem like overkill, but seeing that your files aren't very large, I'm tempted to leverage the following one-liner (either from the command line or via a system call).
The one-liner works by slurping all the lines in one shot, then leaving the rest of the work to a regex substitution which flips the order of the lines.
If you're using *nix:
perl -0777 -i -ne 's/(TITLE.*?")\n(PERFORMER.*?")/$2\n$1/g' file1 file2 ..
If you're using Windows, you'll need to create a backup of the existing files:
perl -0777 -i.bak -ne "s/(TITLE.*?\")\n(PERFORMER.*?\")/$2\n$1/g" file1 file2 ..
Explanation
Command Switches (see perlrun for more info)
-0777 (an octal number) enforces file-slurping behavior
-i enables in-place editing (no need to splice-'n'-dice!). Windows systems require that you provide a backup extension, hence the additional .bak
-n loops over all lines in your file(s) (although since you're slurping them in, Perl treats the contents of each file as one line)
-e allows Perl to recognize code within the command-line
Regex
The substitution regex captures all occurrences of the TITLE line, the consecutive PERFORMER line, and stores it in variables $1 and $2 respectively. The substitution regex then flips the order of the two variables, separated with a newline.
Filename Arguments
You could use *nix to provide the filenames of the directories in question, but I'll leave that to someone else to figure out as I'm not too comfortable with Unix pipes just yet (see this John Siracusa answer for more guidance).
I would create a backup of your files before you try these one-liners though.
Well, since you're tying into an array, I'd just check $lines[$i] and $lines[$i+1] (as long as the +1 address exists, that is), and if the former matches TITLE and the latter PERFORMER, swap them. Unless perhaps you need to transpose these even if they're not consecutive??
Here's an option (this snippet would go inside your for loop, perhaps above the REM-checking line) if you know they'll be consecutive:
if ($i < $#lines and $lines[$i] =~ /^TITLE.*?"$/
and $lines[$i+1] =~ /^PERFORMER.*?$/) {
my $tmp = $lines[$i];
$lines[$i] = $lines[$i+1];
$lines[$i+1] = $tmp;
}
Another option (which would work regardless of consecutiveness, and is arguably more elegant) would be to
use List::MoreUtils qw(first_index);
(up at the top, with your other use statements) and then do (inside &c, but outside the for loop):
my $title_idx = first_index { /^TITLE.*?"$/ } #lines;
my $performer_idx = first_index { /^PERFORMER.*?"$/ } #lines;
if($title_idx >= 0 and $performer_idx >= 0 and $title_idx < $performer_idx)
{
# swap these lines:
($lines[$title_idx],$lines[$performer_idx]) =
($lines[$performer_idx],$lines[$title_idx]);
}
Is that what you're after?