my $guid = `uuidgen.exe`;
chomp $guid;

Uuuidgen.exe is a tool from DotNet Framework. You can append "-c" option to generate uppercase letters

Run uuidgen /? to see the detail usage of uuidgen.
Microsoft UUID Generator v1.01 Copyright (c) Microsoft Corporation. All rights reserved.

usage: uuidgen [-xisconvh?]
        x – Generate sequential (V1) UUIDs
        i – Output UUID in an IDL interface template
        s – Output UUID as an initialized C struct
        c – Output UUID in upper case
        o<filename> – redirect output to a file, specified immediately after o
        n<number> – Number of UUIDs to generate, specified immediately after n
        v – display version information about uuidgen
        h,? – Display command option summary

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my $file = $ARGV[0];
my $filetmp = "$ARGV[0].tmp";
open (INPUT, "< $file") or die("Unable to open $file");
open (TMP, "> $filetmp") or die("Unable to open $filetmp");
while(<INPUT>) {
    if(/foo/) {
        s/foo/bar/;   # replace foo with bar   
    }
    print TMP $_;
}
close(INPUT);
close(TMP);
rename $filetmp, $file;

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Example

$strings=”foo,bar,test”;
my @fields = split(/,/, $strings);
print $fields[-1] ;  # the last str in $strings

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Here is an example example,  in following code we try to replace c:\foo to d:\bar for a given directory name.

my $dir = "c:\\foo\\test";
my $foo = " c:\\foo";
my $bar = " d:\\bar";
$str =~ s/$a/$b/g;    # this prints c:\foo\test

The code will not work as backslashes are escaped to \\ in regular expression pattern, after using \Q and \E to escape backslashes in pattern,

my $dir = "c:\\foo\\test";
my $foo = " c:\\foo";
my $bar = " d:\\bar";
$str =~ s/\Q$a\E/$b/g;    # this prints d:\bar\test

Now we get what we expected.

More information can be found at

http://www.sdsc.edu/~moreland/courses/IntroPerl/docs/manual/pod/perlre.html

\E end case modification (think vi)

\Q quote (disable) pattern metacharacters till \E

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Here is an example example,  in following code we try to replace c:\foo to d:\bar for a given directory name.

my $dir = “c:\\foo\\test”;
my $foo = ” c:\\foo”;
my $bar = ” d:\\bar”;
$dir =~ s/$foo/$bar/g;    # this prints c:\foo\test

The code will not work as backslashes are escaped to \\ in regular expression pattern, after using \Q and \E to escape backslashes in pattern,

my $dir = “c:\\foo\\test”;
my $foo = “c:\\foo”;
my $bar = “d:\\bar”;
$str =~ s/\Q$foo\E/$bar/g;    # this prints d:\bar\test

Now we get what we expected.

More information can be found at

http://www.sdsc.edu/~moreland/courses/IntroPerl/docs/manual/pod/perlre.html

\E end case modification (think vi)

\Q quote (disable) pattern metacharacters till \E

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my $dir="d:\\bin";
$ENV{PATH}.=";$dir";

Then $dir will be included in new $ENV{PATH}

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sub ExecuteCommand {
my $cmd= $_;
my @cmdoutput = `$cmd`;
for $line (@cmdoutput) {
print $line;
}

Now just change your code from system($command) or `$command` to ExecuteCommand($command) and you will see all command output are redirected to console.

En, good but …

I want to see the command that it’s running

Just add print following line prior the call of command.

print “Now running $cmd …\n”;

or call your logging subrountine.

I want to know return code of $cmd

Use my $cmdexitcode = $? >> 8; to get the return code of $cmd and then add     return $cmdexitcode; at the end of ExecuteCommand

I want to pass more than one command to ExecuteCommand

Try this version

sub ExecuteCommand {
@cmdlist = (@_);
my $cmd = join(” \& “, @cmdlist);
my @cmdoutput = `$cmd`;
my $cmdexitcode = $? >> 8;
for $line (@cmdoutput) {
print $line;
}
return $cmdexitcode;
}

Now you should call ExecuteCommand like this when you want to pass more than one command.

push @cmdlist, $cmd1;
push @cmdlist, $cmd2;
push @cmdlist, $cmd3;
ExecuteCommand(@cmdlist);

And $cmd1, cmd2, cmd3 will be run in one context shell.

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