Re: use of $sub

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Re^2: use of $sub by JimLS (Novice) on Oct 19, 2012 at 14:20 UTC
smdr appears in the text of the error message of the code I linked to in the same line of the code that has $sub. I think it may have simply been something to do with the original use of the code. It wasn't part of a system error output. Yes, the error is 'used only once' as you stated. I think my real question is how do I use $sub with 'use warnings' and not get the warning? Also, the links I found on the use of sub were "sub" rather than "$sub" and I would like to understand the addition of "$".	[reply]
Re^3: use of $sub by tobyink (Canon) on Oct 19, 2012 at 14:30 UTC
I would like to understand the addition of "$" Not, `"$"` but `"$!"`. The exclamation mark is not just for decoration. See perlvar. `perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'`	[reply] [d/l] [select]
Re^4: use of $sub by JimLS (Novice) on Oct 19, 2012 at 15:57 UTC
Not, "$" but "$!". No, I don't mean "$!". I looked up "$!" and understood that. I mean the addition of "$" to "SUB" resulting in "$SUB".	[reply]
Re^5: use of $sub by tobyink (Canon) on Oct 19, 2012 at 16:09 UTC
Re^6: use of $sub by JimLS (Novice) on Oct 19, 2012 at 17:03 UTC
Re^3: use of $sub by roboticus (Chancellor) on Oct 19, 2012 at 14:50 UTC
JimLS: I expect that just adding something like this: `sub PREVENT_USELESS_WARNING { my $t = $sub }` [download] or similar shenanigans would do fine. ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply] [d/l]
Re^3: use of $sub by Anonymous Monk on Oct 19, 2012 at 14:27 UTC
Go ahead and add `use diagnostics;` to see $ perl -Mdiagnostics -e " $foo = 1; " Name "main::foo" used only once: possible typo at -e line 1 (#1) (W once) Typographical errors often show up as unique variable nam +es. If you had a good reason for having a unique name, then just menti +on it again somehow to suppress the message. The our declaration is provided for this purpose. NOTE: This warning detects symbols that have been used only once s +o $c, @c, %c, *c, &c, sub c{}, c(), and c (the filehandle or format) are con +sidered the same; if a program uses $c only once but also uses any of the +others it will not trigger this warning. [download] warnings are useful, but adding strict is better. Read this if you want to cut your development time in half! explains how/why to use them.	[reply] [d/l]
Re^3: use of $sub by toolic (Bishop) on Oct 19, 2012 at 14:38 UTC
smdr is inside a quoted string of text. You have to ask the original author what he meant by smdr. not get the warning? Like I said, you need to assign a value to $SUB, or just delete the variable if you don't need it.	[reply]