string substitution in perl

Shell Programming and Scripting
1

Hi,

I have a template file and want to replace 3 parameters to the values that I want. these values are in a parameter file.

Any idea how to do this in perl?

the parameter file looks like:

host_name = jupiter
PORT = 1562
IPADDRESS = 10.1.34.10

the template file has lots of entry.

CX_HOST_NAME = host_name
CX_IPADDRESS = ip_address
CX__PORT = port

thanks.

2

i'm not a perl monk . . . but this works:

#!/usr/bin/perl

#----------------------------------------------------------------------#
# Read both files into arrays...                                       #
#----------------------------------------------------------------------#
$param_file = "parameters.dat";

unless ( open FIN, "$param_file" ){
  print "cannot open $param_file \n";
  exit(1);
  }

@a_parameters = <FIN>; chomp @a_parameters; close FIN;

$template_file = "template.dat";

unless ( open FIN, "$template_file" ){
  print "cannot open $template_file \n";
  exit(1);
  }

@a_template = <FIN>; chomp @a_template; close FIN;

#----------------------------------------------------------------------#
# Peruse one array...                                                  #
#----------------------------------------------------------------------#
for $x ( 0 .. scalar( @a_parameters ) - 1 ){
  ( $var_name, $equals, $var_value ) = split( / /, $a_parameters[$x] );
  $var_name = uc( $var_name );
#----------------------------------------------------------------------#
# Looking for values in the other...                                   #
#----------------------------------------------------------------------#
  for $y ( 0 .. scalar( @a_template ) - 1 ){
    next unless ( $template[$y] = m/CX_*$var_name = / );
#----------------------------------------------------------------------#
# Substitute the template with the parameter...                        #
#----------------------------------------------------------------------#
    $a_template[$y] =~ s/= .*$/= $var_value/;
    }
  }

#----------------------------------------------------------------------#
# ... and print.                                                       #
#----------------------------------------------------------------------#
for $y ( 0 .. scalar( @a_template ) - 1 ){
  print "template entry " . ( $y + 1 ) . ": $a_template[$y] \n";
  }