"Other"? Ah, I didn't realize Internals::SvREADONLY could. Yes, it just exports SvREADONLY_on(sv) and SvREADONLY_off(sv) to Perl land.

It sounds like you are trying to prevent someone from preventing you from making variables read-only. All I pointed out that it's moot since they can undo your work should you manage to get it done.

But you know what, one doesn't even need to make the variable not readonly to change it. The READONLY flag is purely advisory. It can simply be ignored.

use strict;
use warnings;

use Inline C => <<'__EOI__';

void change_it(SV* sv) {
    SvIV_set(sv, 789);
    SvIOK_only(sv);
}

__EOI__

my $i = 123;
Internals::SvREADONLY($i, 1);
print("$i\n");

eval { $i = 456; };
print("$i\n");

change_it($i);
print("$i\n");
[download]

123
123
789
[download]

Update: Added realisation that READONLY if advisory.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.