The only way I'm aware of to compile but not execute code in a variable is to wrap it in an anonymous subroutine block: 
my $goodcode = <<'CODE';
print "Hello, how are you?\n"
CODE

my $badcode = <<'CODE';
pront "Hello, how are you\n?'
CODE

{
    no strict;
    local $^W = 0;
    eval "sub {\n$goodcode\n}";
}
print "Goodcode error: $@\n" if $@;

{
    no strict;
    local $^W = 0;
    eval "sub {\n$badcode\n}";
}
print "Badcode error: $@\n" if $@;

[download]
You can get more elaborate if you like, writing your own warning handler to capture them instead of printing them. It's late and I shouldn't be posting.

Oh, and the newlines are in there in case you have comments somewhere in your code string. I did once, and it commented out the ending brace of the sub. Beware.

Update: If you want to suppress or log warnings, you can get rid of the 'no strict' and 'local' lines, and use a variant of this instead: local $SIG{__WARN__} = sub {};

It'll create and throw away a new anonymous sub (unless eval() checks for void context -- I dunno), but it'll do the compile-but-not-execute waltz.

In reply to Re: Syntax Error Checking by chromatic
in thread Syntax Error Checking by madhatter

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