Following script, I'm using which performs everything well except it adds three extra curly brackets at the end of file.
abc.jso contains many lines where few lines have only opening/closing curly brackets (In case, this information helps)
I tried by making print $a " $var"; instead of print $a "$var";. In short I added space in front of this print & it worked.
open (my $a,'+<',"abc.jso") or die $!;
my #lines=<$a>;
seek $a,0,0;
while (#lines) {
my $var = shift #lines;
if ($var=~ /^\s*\"(netlist|filelist)\" : \".*$blk.*\",/) {
print $a " \"netlist\" : \"/t98/pnr/work/$blk"."_rk/run/dc/$blk"."_post_dft.v\",\n";
$count++;
print "Netlist got replaced\n";
}
elsif ($var=~ /^\s*\"spf\" : \".*$blk.*\"/) {
print $a " \"spf\" : \"/t98/scan/atpg/t98_1.0/spf/$blk".".scan_compress.spf\"\n";
$count++;
print "SPF got replaced\n";
}
else {
print $a "$var";
}
}
close($a);
Can someone explain, why it is happening? Is there any such corner case of text handling that I'm not aware of?
Having some sample input and output would help but let me take a guess. Try truncating the file by the seek:
truncate $a,0;
seek $a,0,0;
Without the truncate you will be overwriting what was there before. This works if you write more information than you read but not so good if you write less than you read.
Related
I'm trying to parse a CSV file that is formatted like this:
dog cats,yellow blue tomorrow,12445
birds,window bank door,-novalue-
birds,window door,5553
aspirin man,red,567
(there is no value where -novalue- is written)
use strict;
use warnings;
my $filename = 'in.txt';
my $filename2 = 'out.txt';
open(my $in, '<:encoding(UTF-8)', $filename)
or die "Could not open file '$filename' $!";
my $word = "";
while (my $row = <$in>) {
chomp $row;
my #fields = split(/,/,$row);
#Save the first word of the second column
($word) = split(/\s/,$fields[1]);
if ($word eq 'importartWord')
{
printf $out "$fields[0]".';'."$word".';'."$fields[2]";
}
else #keep as it was
{
printf $out "$fields[0]".';'."$fields[1]".';'."$fields[2]";
}
Use of uninitialized value $word in string ne at prueba7.pl line 22, <$in> line 10.
No matter where I define $word I cannot stop receiving that error and can't understand why. I think I have initialized $word correctly. I would really appreciate your help here.
Please if you are going to suggest using Text::CSV post a working code example since I haven't been able to apply it for the propose I have explained here. That's the reason I ended up writing the above code.
PD:
Because I know you are going to ask for my previous code using Text::CSV, here it is:
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
my $csv = Text::CSV->new({ sep_char => ';', binary => 1 }) or
die "Cannot use CSV: ".Text::CSV->error_diag ();
#directorio donde esta esc_prim2.csv
my $file = 'C:\Users\Sergio\Desktop\GIS\perl\esc_prim2.csv';
my $sal = 'C:\Users\Sergio\Desktop\GIS\perl\esc_prim3.csv';
open my $data, "<:encoding(utf8)", "$file" or die "$file: $!";
open my $out, ">:encoding(utf8)", "$sal" or die "$sal: $!";
$csv->eol ("\r\n");
#initializing variables
my $row = "";
my $word = "";
my $validar = 0;
my $line1 = "";
my #mwords = [""];#Just a try to initialize mwords... doesn't work, error keeps showing
#save the first line with field names on the other file
$line1 = <$data>;
$csv->parse($line1);
my #fields = $csv->fields();
$csv->print($out,[$fields[0], $fields[1], $fields[2]]);
while ($row = <$data>) {
if ($csv->parse($row)) {
#fields = $csv->fields();
#save first word of the field's second element
#mwords = split (/\s/, $fields[1]);
#keep the first one
$word = $mwords[0];
printf($mwords[0]);
#if that word is not one of SAN, EL y LA... writes a line in the new file with the updated second field.
$validar = ($word ne 'SAN') && ($word ne 'EL') && ($word ne 'LA');
if ($validar)
{
$csv->print($out,[$fields[0], $word, $fields[2]]);
}
else { #Saves the line in the new file as it was in the old one.
$csv->print($out,[$fields[0], $fields[1], $fields[2]]);
}
} else {#error procesing row
warn "La row no se ha podido procesar\n";
}
}
close $data or die "$file: $!";
close $out or die "$sal: $!";
Here the line where $validar is declared brings the same error of "uninitialized value" although I did it.
I also tried the push #rows, $row; approach but I don't really know how to handle the $rows[$i] since they are references to arrays (pointers) and I know they can't be operated as variables... Couldn't find a working example on how to use them.
I think you're misunderstanding the error. It's not a problem with the declaration of the variable, but with the data that you're putting into the variable.
Use of uninitialized value
This means that you are trying to use a value that is undefined (not undeclared). That means you are using a variable that you haven't given a value.
You can get more details about the warning (and it's a warning, not an error) by adding use diagnostics to your code. You'll get something like this:
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
To help you figure out what was undefined, perl will try to tell you
the name of the variable (if any) that was undefined. In some cases
it cannot do this, so it also tells you what operation you used the
undefined value in. Note, however, that perl optimizes your program
and the operation displayed in the warning may not necessarily appear
literally in your program. For example, "that $foo" is usually
optimized into "that " . $foo, and the warning will refer to the
concatenation (.) operator, even though there is no . in
your program.
So, when you're populating $word, it's not getting a value. Presumably, that's because some lines in your input file have an empty record there.
I have no way of knowing whether or not that's a valid input for your program, so I can't really give any helpful suggestions on how to fix this.
The error message you provided ends with: line 22, <$in> line 10. but your question doesn't show line 10 of the data ($in) requiring some speculation in this answer - but, I'd say that the second field, $field[1], of line 10 of in.txt is empty.
Consequently, this line: ($word) = split(/\s/,$fields[1]); is causing $word to be undefined. As a result, some use of it latter - be it the ne operator (as displayed in the message) or anything else is going to generate an error.
As an aside - there's little point in interpolating a variable in a string on its own; instead of "$fields[0]", say $fields[0] unless you're going to put something else in there, like "$fields[0];". You may want to consider replacing
printf $out "$fields[0]".';'."$word".';'."$fields[2]";
with
printf $out $fields[0] . ';' . $word . ';' . $fields[2];
or
printf $out "$fields[0];$word;$fields[2]";
Of course, TMTOWTDI - so you may want to tell me to mind my own business instead. :-)
I want to write a perl program for opening a file and reading its content and the printing the number of lines, words and characters there are. I also want to print the number of times a specific word appeared in the file. Here is what I have done:
#! /usr/bin/perl
open( FILE, "test1.txt" ) or die "could not open file $1";
my ( $line, $word, $chars ) = ( 0, 0, 0 );
while (<FILE>) {
$line++;
$words += scalar( split( /\s+/, $_ ) );
$chars += length($_);
print $_;
}
$chars -= $words;
print(
"Total number of lines in the file:= $line \nTotal number of words in the file:= $words \nTotal number of chars in the file:= $chars\n"
);
As you can clearly see, I don't have any provision for taking user input of the words whose occurrence is to be counted. Because I don't know how to do it. Please help with counting of the number of occurrence part. Thank you
I guess you're doing this for learning purposes, so here is a good readable version of your problem (there might be a thousand others, because it's perl). If not, there's wc on the linxux command line.
Note that I'm using three argument open, it's generally better to do that.
For counting single words you'll most probably need a hash. And I used <<HERE docs, because they are nicer for formating. If you have any doubts, just look in the perldoc and ask your questions.
#!/usr/bin/env perl
use warnings; # Always use this
use strict; # ditto
my ($chars,$word_count ,%words);
{
open my $file, '<', 'test.txt'
or die "couldn't open `test.txt':\n$!";
while (<$file>){
foreach (split){
$word_count++;
$words{$_}++;
$chars += length;
}
}
} # $file is now closed
print <<THAT;
Total number of lines: $.
Total number of words: $word_count
Total number of chars: $chars
THAT
# Now to your questioning part:
my $prompt= <<PROMPT.'>>';
Please enter the words you want the occurrences for. (CTRL+D ends the program)
PROMPT
print $prompt;
while(<STDIN>){
chomp; # get rid of the newline
print "$_ ".(exists $words{$_}?"occurs $words{$_} times":"doesn't occur")
." in the file\n",$prompt;
}
I am writing a program that takes numbers from the command line until the user enters a blank line.
Should the user enter something that is neither newline nor numeric, it notifies the user, and continues.
While everything works, I have use warnings turned on, and it doesn't seem to like the second if conditional if the enters something invalid.
Argument "foo" isn't numeric in numeric eq (==) at adder.pl line 25, <STDIN> line 4.
I don't like running the program with this warning. How can I improve my code?
This is my program
#!/usr/bin/perl
use strict;
use warnings;
#declare variable
my $number = 0; #final answer
my $input;
#prompt the user
print "Input some integers, line by line. When you are done, press return to add them up." . "\n";
while (1) {
#get input from user
$input = <STDIN>;
#remove newlines
chomp($input);
#user pnches in newline
if ($input eq '') { #if the answer is new line
#quit the loop
last;
} #end of if statement
#user punches in bad input
elsif ($input == 0 && $input ne '0' && $input ne '') {
#tell the user what happened and how to rectify it
print "Input must be an integer." . "\n";
} # end of elsif statement
else {
chomp($input);
$number += $input;
} # end of else statement
} #end of while
print "Total is: $number\n";
Perl does DWIM very well. It is famous for it.
So, whatever language you have come from - it looks like C - forget about checking for both strings and numbers: a Perl scalar variable is whatever you ask it to be.
That means something like
elsif ($input == 0 && $input ne '0' && $input ne '') {
makes little sense. Anything read from the keyboard is initially a string, but it will be a number if you want. You are asking for $input to evaluate as zero but not to be the literal string 0. That applies to very few strings, for instance 00 or 0e0.
I think this is what you meant to write. Please take a look.
Isn't it clearer without comments?
use strict;
use warnings;
print "Input some integers line by line. When you are done, press return to add them up\n";
my $total = 0;
while (<>) {
chomp;
last unless /\S/;
if (/\D/) {
print "Input must be an integer\n";
next;
}
$total += $_;
}
print "Total is: $total\n";
Since Perl is untyped, and you are using $input as both a number and a string, you get that warning because "foo" isn't a number and "==" is used to compare equality of numbers.
You first need to check to see if $input is a number or not. One suggestion:
if ($input =~ /^\d+$/)
{
$number += $input;
}
else
{
print "Input must be an integer.\n";
}
According to my research the '\b' character used in perl print statements should act like a "backspace", that is, moving the cursor one character back, and deleting the current character. For this reason, I had planned to use this operation to print operational status on a single line, updating as it progressed. However, I noticed that while the cursor does indeed move back, the characters underfoot are not deleted, and therefore, longer messages remain after shorter print statements. I have compiled the following sample code to explain my findings:
#!/usr/bin/perl
use strict;
use warnings;
my $m;
#set to nonzero so that the screen will update before \n
local $| = 1;
print "Current number shown: ";
$m = "LONG MESSAGE TEMP";
print $m;
print "\b" x length($m);
foreach(1..22) {
$m = $_;
print $m;
print "\b" x length($m);
#sleep 1; #Uncomment to see updates
}
print "\n";
And this was the output:
Current number shown: 22NG MESSAGE TEMP
If this is indeed the correct operation of '\b', is there another escape that deletes the character as well as moving the cursor back? I would like to avoid using '\r' which starts at the beginning of the current line. Otherwise, how am I using the escapes incorrectly?
"\b" is just a fancy way of writing chr(0x08). Your terminal will likely move the cursor rather than display anything, but that's entirely up to it.
If you can rely on it, then you can achieve what you want by overwriting with spaces.
my $last_length = 0;
sub update {
my ($s) = #_;
print("\b" x $last_length);
print(" " x $last_length);
print("\b" x $last_length);
print($s);
$last_length = length($s);
}
Or with less flicker:
my $last_length = 0;
sub update {
my ($s) = #_;
my $diff = $last_length - length($s);
print("\b" x $last_length);
print($s);
print(" " x $diff);
print("\b" x $diff);
$last_length = length($s);
}
Just output some extra space characters to overwrite what you need to overwrite.
#!/usr/bin/env perl
use strict;
use warnings;
use Time::HiRes qw(sleep);
sub backspace {
print "\b" x $_[0];
print " " x $_[0];
print "\b" x $_[0];
}
local $| = 1;
my $m = "LONG MESSAGE TEMP";
print "Current number shown: ", $m;
sleep 1;
for (1..22) {
backspace( length($m) );
$m = $_;
print $m;
sleep 0.2;
}
print "\n";
Depending on how it is used, \b can have a special meaning within a Perl command:
\b is the backspace character only inside a character class. Outside a character class, \b alone is a word-character/non-word-character boundary.
To substitute "def" for each occurrence of the word "ABC" within a file, use the Perl command:
perl -pi -e 's/\bABC\b/def/g' file
which will leave strings such as "ZABCD" unchanged.
I wrote a super simple script:
#!/usr/bin/perl -w
use strict;
open (F, "<ids.txt") || die "fail: $!\n";
my #ids = <F>;
foreach my $string (#ids) {
chomp($string);
print "$string\n";
}
close F;
This is producing an expected output of all the contents of ids.txt:
hello
world
these
annoying
sourcecode
lines
Now I want to add a file-extension: .txt for every line. This line should do the trick:
#!/usr/bin/perl -w
use strict;
open (F, "<ids.txt") || die "fail: $!\n";
my #ids = <F>;
foreach my $string (#ids) {
chomp($string);
$string .= ".txt";
print "$string\n";
}
close F;
But the result is as follows:
.txto
.txtd
.txte
.txtying
.txtcecode
Instead of appending ".txt" to my lines, the first 4 letters of my string will be replaced by ".txt" Since I want to check if some files exist, I need the full filename with extension.
I have tried to chop, chomp, to substitute (s/\n//), joins and whatever. But the result is still a replacement instead of an append.
Where is the mistake?
Chomp does not remove BOTH \r and \n if the file has DOS line endings and you are running on Linux/Unix.
What you are seeing is actually the original string, a carriage return, and the extension, which overwrites the first 4 characters on the display.
If the incoming file has DOS/Windows line endings you must remove both:
s/\R+$//
A useful debugging technique when you are not quite sure why your data is getting set to what it is is to dump it with Data::Dumper:
#!/usr/bin/perl -w
use strict;
use Data::Dumper ();
$Data::Dumper::Useqq = 1; # important to be able to actually see differences in whitespace, etc
open (F, "<ids.txt") || die "fail: $!\n";
my #ids = <F>;
foreach my $string (#ids) {
chomp($string);
print "$string\n";
print Data::Dumper::Dumper( { 'string' => $string } );
}
close F;
have you tried this?
foreach my $string (#ids) {
chomp($string);
print $string.".txt\n";
}
I'm not sure what's wrong with your code though. these results are strange