Re: Making strict optional

Here you go,

eval 'use strict';
if ($@) {  # If it cannot 'use strict' then it will put the error in $
+@
  print "Cannot 'use strict', it appears to be missing\n";
}
[download]

Put this in your code, and it will print a message if it cannot load strict for whatever reason. You can take out the message if you want.

Update: Put the {} for the eval command in the wrong place... Just taking them out altogether and removing it from the BEGIN block. At least I learned something today.

Comment on Re: Making strict optional Download Code

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Re^2: Making strict optional by ikegami (Patriarch) on May 31, 2006 at 15:08 UTC
While that trick can be used for detecting if `strict` exists, it won't turn strict on. `strict ends here \| \| BEGIN { v eval 'use strict'; warn("Cannot 'use strict', it appears to be missing\n") if $@; }` [download] On the other hand, the following works (and doesn't use `eval EXPR`): `BEGIN { eval { require strict }; if ($@) { warn("Cannot 'use strict', it appears to be missing\n"); } else { strict->import(); } }` [download]	[reply] [d/l] [select]
Re^2: Making strict optional by Fletch (Bishop) on May 31, 2006 at 15:08 UTC
Seeing how strict is lexically scoped using it inside of an `eval` inside of a BEGIN block's scope isn't really going to do the rest of one's code much good . . .	[reply] [d/l]
Re^3: Making strict optional by gellyfish (Monsignor) on May 31, 2006 at 15:11 UTC
Well you might say that: `BEGIN { eval { require strict; }; strict->import() unless $@; } + $foo = 1;` [download] Gives rise to: `Global symbol "$foo" requires explicit package name at hdhd line 10. Execution of hdhd aborted due to compilation errors.` [download] ~~So no it does work.~~ Update: but of course the string eval is different. /J\	[reply] [d/l] [select]
Re^2: Making strict optional by betterworld (Curate) on May 31, 2006 at 15:13 UTC
The problem with that is that the following script compiles without complaints (even when strict is available) and prints "5". `sub BEGIN { { eval 'use strict' } } $not_declared = 5; print $not_declared, "\n";` [download] "use strict" is always local for the surrounding block, so you cannot put it into eval or BEGIN.	[reply] [d/l]