Re: using command line switches to edit file

[physi]

Hmm, don't really understand what you are doing there, but:

 while (<INFO>)
{
  $line=<INFO>;
}  
close INFO;  
  my @new2;
  if($var{param}) { list_param($var{param}); }
  if($var{the})   { list_the($var{the}); }

You read in the whole file, and do nothing, but overwrite your $line. After theat you call yout sub's with the $line, which now contains only the last line of your inputfile. Maybe you should try to put the sub-calls into the while loop!? And if you want to replace everytime the same, than this maybe will work to:

perl -p -e 's/yourstring/yournewstring/g' inputfile > outputfile

But that might not that flexible as you need...

[kitty]

The test-file contents are of the form :

<PROP GUID="471138786526914052" EXPR="≪E The_Rounding_Unit=&Quot;1e-16&Quot; Absolute_Error_Tolerance=&Quot;1e-15&Quot; /&Gt";"/>

How do i extract the numerical values (in bold) from the above fileformat? I need to substitute it with the user input from the command line.

while (<INFO>)
{
  @line=<INFO>; #will this help ?
  my @new2;
  if($var{param}) { list_param($var{param}); }
  if($var{the})   { list_the($var{the}); }

sub list_param($)
{        
   if ($line =~ m:Absolute_Error_Tolerance=&quot:)
      {
          $line=$line1;
          @new2=split(/\&quot;/,$line1);
          $line1=~s/$new2[1]/$G{param}/;
       }
}

[holli]

@line=<INFO>; #will this help ?

Not at all. That construct will read the whole file into an array lines. That's not what you want here. Have a look at this code.

my $file = $ARGV[0];
my $repl = $ARGV[1];

open INFO, "<", $file or die $!;

while (<INFO>)
{
    s/(Absolute_Error_Tolerance=&Quot;)1e-15(&Quot)/$1$repl$2/;
    print;
}

close INFO;

That can be easily made into a one-liner:

perl -n -e "s/(Absolute_Error_Tolerance=&Quot;)1e-15(&Quot)/$1$ARGV[0]
+$2/;
    print;" filename

just this doesn't work. You cannot pass additional variables into an -e "code" statement. However, you avoid problem by putting that line into a shell script or batchfile (here windows batchfile, as i have no idea of shell scripts).

@echo off
perl -n -e "s/(Absolute_Error_Tolerance=&Quot;)1e-15(&Quot)/$1%2$2/; p
+rint;" %1

So you can then call that file using

batchfilename datafile replacement

Note: The %1 and %2 are no perl hashes but variables from the shell. They get substituted by the command line values before! the script is run.

[kitty]

Thankyou :) ..