op

source of perl for linux application,

use warnings 'misc' ;
my $a ; my @a = () ; my %a = () ; my $b = \@a ; my $c = \%a ;
@a =~ /abc/ ;
@a =~ s/a/b/ ;
@a =~ tr/a/b/ ;
@$b =~ /abc/ ;
@$b =~ s/a/b/ ;
@$b =~ tr/a/b/ ;
%a =~ /abc/ ;
%a =~ s/a/b/ ;
%a =~ tr/a/b/ ;
%$c =~ /abc/ ;
%$c =~ s/a/b/ ;
%$c =~ tr/a/b/ ;
{
no warnings 'misc' ;
my $a ; my @a = () ; my %a = () ; my $b = \@a ; my $c = \%a ;
@a =~ /abc/ ;
@a =~ s/a/b/ ;
@a =~ tr/a/b/ ;
@$b =~ /abc/ ;
@$b =~ s/a/b/ ;
@$b =~ tr/a/b/ ;
%a =~ /abc/ ;
%a =~ s/a/b/ ;
%a =~ tr/a/b/ ;
%$c =~ /abc/ ;
%$c =~ s/a/b/ ;
%$c =~ tr/a/b/ ;
}
EXPECT
Applying pattern match (m//) to @array will act on scalar(@array) at - line 5.
Applying substitution (s///) to @array will act on scalar(@array) at - line 6.
Applying transliteration (tr///) to @array will act on scalar(@array) at - line 7.
Applying pattern match (m//) to @array will act on scalar(@array) at - line 8.
Applying substitution (s///) to @array will act on scalar(@array) at - line 9.
Applying transliteration (tr///) to @array will act on scalar(@array) at - line 10.
Applying pattern match (m//) to %hash will act on scalar(%hash) at - line 11.
Applying substitution (s///) to %hash will act on scalar(%hash) at - line 12.
Applying transliteration (tr///) to %hash will act on scalar(%hash) at - line 13.
Applying pattern match (m//) to %hash will act on scalar(%hash) at - line 14.
Applying substitution (s///) to %hash will act on scalar(%hash) at - line 15.
Applying transliteration (tr///) to %hash will act on scalar(%hash) at - line 16.
Can't modify private array in substitution (s///) at - line 6, near "s/a/b/ ;"
BEGIN not safe after errors--compilation aborted at - line 18.
########
# op.c
use warnings 'parenthesis' ;
my $a, $b = (1,2);
my @foo,%bar,	$quux; # there's a TAB here
my $x, $y or print;
no warnings 'parenthesis' ;
my $c, $d = (1,2);
EXPECT
Parentheses missing around "my" list at - line 3.
Parentheses missing around "my" list at - line 4.
########
# op.c
use warnings 'parenthesis' ;
our $a, $b = (1,2);
no warnings 'parenthesis' ;
our $c, $d = (1,2);
EXPECT
Parentheses missing around "our" list at - line 3.
########
# op.c
use warnings 'parenthesis' ;
local $a, $b = (1,2);
local *f, *g;
no warnings 'parenthesis' ;
local $c, $d = (1,2);
EXPECT
Parentheses missing around "local" list at - line 3.
Parentheses missing around "local" list at - line 4.
########
# op.c
use warnings 'bareword' ;
print (ABC || 1) ;
no warnings 'bareword' ;
print (ABC || 1) ;
EXPECT
Bareword found in conditional at - line 3.
########
--FILE-- abc

--FILE--
# op.c
use warnings 'misc' ;
open FH, "<abc" ;
$x = 1 if $x = <FH> ;
no warnings 'misc' ;
$x = 1 if $x = <FH> ;
EXPECT
Value of <HANDLE> construct can be "0"; test with defined() at - line 4.
########
# op.c
use warnings 'misc' ;
opendir FH, "." ;
$x = 1 if $x = readdir FH ;
no warnings 'misc' ;
$x = 1 if $x = readdir FH ;
closedir FH ;
EXPECT
Value of readdir() operator can be "0"; test with defined() at - line 4.
########
# op.c
use warnings 'misc' ;
$x = 1 if $x = <*> ;
no warnings 'misc' ;
$x = 1 if $x = <*> ;
EXPECT
Value of glob construct can be "0"; test with defined() at - line 3.
########
# op.c
use warnings 'misc' ;
%a = (1,2,3,4) ;
$x = 1 if $x = each %a ;
no warnings 'misc' ;
$x = 1 if $x = each %a ;
EXPECT
Value of each() operator can be "0"; test with defined() at - line 4.
########
# op.c
use warnings 'misc' ;
$x = 1 while $x = <*> and 0 ;
no warnings 'misc' ;
$x = 1 while $x = <*> and 0 ;
EXPECT
Value of glob construct can be "0"; test with defined() at - line 3.
########
# op.c
use warnings 'misc' ;
opendir FH, "." ;
$x = 1 while $x = readdir FH and 0 ;
no warnings 'misc' ;
$x = 1 while $x = readdir FH and 0 ;
closedir FH ;
EXPECT
Value of readdir() operator can be "0"; test with defined() at - line 4.
########
# op.c
use warnings 'misc';
open FH, "<abc";
($_ = <FH>) // ($_ = 1);
opendir DH, ".";
%a = (1,2,3,4) ;
EXPECT
########
# op.c
use warnings 'redefine' ;
sub fred {}
sub fred {}
no warnings 'redefine' ;
sub fred {}
EXPECT
Subroutine fred redefined at - line 4.
########
# op.c
use warnings 'redefine' ;
sub fred () { 1 }
sub fred () { 1 }
no warnings 'redefine' ;
sub fred () { 1 }
EXPECT
Constant subroutine fred redefined at - line 4.
########
# op.c
no warnings 'redefine' ;
sub fred () { 1 }
sub fred () { 2 }
EXPECT
Constant subroutine fred redefined at - line 4.
########
# op.c
no warnings 'redefine' ;
sub fred () { 1 }
*fred = sub () { 2 };
EXPECT
Constant subroutine main::fred redefined at - line 4.
########
# op.c
use warnings 'redefine' ;
format FRED =
.
format FRED =
.
no warnings 'redefine' ;
format FRED =
.
EXPECT
Format FRED redefined at - line 5.
########
# op.c
use warnings 'deprecated' ;
push FRED;
no warnings 'deprecated' ;
push FRED;
EXPECT
Array @FRED missing the @ in argument 1 of push() at - line 3.
########
# op.c
use warnings 'deprecated' ;
@a = keys FRED ;
no warnings 'deprecated' ;
@a = keys FRED ;
EXPECT
Hash %FRED missing the % in argument 1 of keys() at - line 3.
########
# op.c
BEGIN {
    if ($^O eq 'MacOS') {
	print <<EOM;
SKIPPED
# no exec on Mac OS
EOM
	exit;
    }
}
use warnings 'syntax' ;
exec "$^X -e 1" ; 
my $a
EXPECT
Statement unlikely to be reached at - line 13.
	(Maybe you meant system() when you said exec()?)
########
# op.c
use warnings 'deprecated' ;
my @a; defined(@a);
EXPECT
defined(@array) is deprecated at - line 3.
	(Maybe you should just omit the defined()?)
########
# op.c
use warnings 'deprecated' ;
defined(@a = (1,2,3));
EXPECT
defined(@array) is deprecated at - line 3.
	(Maybe you should just omit the defined()?)
########
# op.c
use warnings 'deprecated' ;
my %h; defined(%h);
EXPECT
defined(%hash) is deprecated at - line 3.
	(Maybe you should just omit the defined()?)
########
# op.c
BEGIN {
    if ($^O eq 'MacOS') {
	print <<EOM;
SKIPPED
# no exec on Mac OS
EOM
	exit;
    }
}
no warnings 'syntax' ;
exec "$^X -e 1" ; 
my $a
EXPECT

########
# op.c
sub fred();
sub fred($) {}
EXPECT
Prototype mismatch: sub main::fred () vs ($) at - line 3.
########
# op.c
$^W = 0 ;
sub fred() ;
sub fred($) {}
{
    no warnings 'prototype' ;
    sub Fred() ;
    sub Fred($) {}
    use warnings 'prototype' ;
    sub freD() ;
    sub freD($) {}
}
sub FRED() ;
sub FRED($) {}
EXPECT
Prototype mismatch: sub main::fred () vs ($) at - line 4.
Prototype mismatch: sub main::freD () vs ($) at - line 11.
Prototype mismatch: sub main::FRED () vs ($) at - line 14.
########
# op.c
use warnings 'syntax' ;
join /---/, 'x', 'y', 'z';
EXPECT
/---/ should probably be written as "---" at - line 3.
########
# op.c [Perl_peep]
use warnings 'prototype' ;
fred() ; 
sub fred ($$) {}
no warnings 'prototype' ;
joe() ; 
sub joe ($$) {}
EXPECT
main::fred() called too early to check prototype at - line 3.
########
# op.c [Perl_newATTRSUB]
--FILE-- abc.pm
use warnings 'void' ;
BEGIN { $| = 1; print "in begin\n"; }
CHECK { print "in check\n"; }
INIT { print "in init\n"; }
END { print "in end\n"; }
print "in mainline\n";
1;
--FILE--
use abc;
delete $INC{"abc.pm"};
require abc;
do "abc.pm";
EXPECT
in begin
in mainline
in check
in init
in begin
Too late to run CHECK block at abc.pm line 3.
Too late to run INIT block at abc.pm line 4.
in mainline
in begin
Too late to run CHECK block at abc.pm line 3.
Too late to run INIT block at abc.pm line 4.
in mainline
in end
in end
in end
########
# op.c [Perl_newATTRSUB]
--FILE-- abc.pm
no warnings 'void' ;
BEGIN { $| = 1; print "in begin\n"; }
CHECK { print "in check\n"; }
INIT { print "in init\n"; }
END { print "in end\n"; }
print "in mainline\n";
1;
--FILE--
require abc;
do "abc.pm";
EXPECT
in begin
in mainline
in begin
in mainline
in end
in end
########
# op.c
my @x;
use warnings 'syntax' ;
push(@x);
unshift(@x);
no warnings 'syntax' ;
push(@x);
unshift(@x);
EXPECT
Useless use of push with no values at - line 4.
Useless use of unshift with no values at - line 5.
########
# op.c
# 20020401 [e-mail] at suggestion of [e-mail]
use warnings 'regexp';
split /blah/g, "blah";
no warnings 'regexp';
split /blah/g, "blah";
EXPECT
Use of /g modifier is meaningless in split at - line 4.
########
# op.c
use warnings 'precedence';
$a = $b & $c == $d;
$a = $b ^ $c != $d;
$a = $b | $c > $d;
$a = $b < $c & $d;
$a = $b >= $c ^ $d;
$a = $b <= $c | $d;
$a = $b <=> $c & $d;
$a &= $b == $c; $a |= $b == $c; $a ^= $b == $c; # shouldn't warn
no warnings 'precedence';
$a = $b & $c == $d;
$a = $b ^ $c != $d;
$a = $b | $c > $d;
$a = $b < $c & $d;
$a = $b >= $c ^ $d;
$a = $b <= $c | $d;
$a = $b <=> $c & $d;
EXPECT
Possible precedence problem on bitwise & operator at - line 3.
Possible precedence problem on bitwise ^ operator at - line 4.
Possible precedence problem on bitwise | operator at - line 5.
Possible precedence problem on bitwise & operator at - line 6.
Possible precedence problem on bitwise ^ operator at - line 7.
Possible precedence problem on bitwise | operator at - line 8.
Possible precedence problem on bitwise & operator at - line 9.
########
# op.c
use integer;
use warnings 'precedence';
$a = $b & $c == $d;
$a = $b ^ $c != $d;
$a = $b | $c > $d;
$a = $b < $c & $d;
$a = $b >= $c ^ $d;
$a = $b <= $c | $d;
$a = $b <=> $c & $d;
no warnings 'precedence';
$a = $b & $c == $d;
$a = $b ^ $c != $d;
$a = $b | $c > $d;
$a = $b < $c & $d;
$a = $b >= $c ^ $d;
$a = $b <= $c | $d;
$a = $b <=> $c & $d;
EXPECT
Possible precedence problem on bitwise & operator at - line 4.
Possible precedence problem on bitwise ^ operator at - line 5.
Possible precedence problem on bitwise | operator at - line 6.
Possible precedence problem on bitwise & operator at - line 7.
Possible precedence problem on bitwise ^ operator at - line 8.
Possible precedence problem on bitwise | operator at - line 9.
Possible precedence problem on bitwise & operator at - line 10.
########
# op.c

# ok	=> local() has desired effect;
# ignore=> local() silently ignored

use warnings 'syntax';

local(undef);		# OP_UNDEF		ignore
sub lval : lvalue {};
local(lval());		# OP_ENTERSUB
local($x **= 1);	# OP_POW
local($x *=  1);	# OP_MULTIPLY
local($x /=  1);	# OP_DIVIDE
local($x %=  1);	# OP_MODULO
local($x x=  1);	# OP_REPEAT
local($x +=  1);	# OP_ADD
local($x -=  1);	# OP_SUBTRACT
local($x .=  1);	# OP_CONCAT
local($x <<= 1);	# OP_LEFT_SHIFT
local($x >>= 1);	# OP_RIGHT_SHIFT
local($x &=  1);	# OP_BIT_AND
local($x ^=  1);	# OP_BIT_XOR
local($x |=  1);	# OP_BIT_OR
{
    use integer;
    local($x *= 1);	# OP_I_MULTIPLY
    local($x /= 1);	# OP_I_DIVIDE
    local($x %= 1);	# OP_I_MODULO
    local($x += 1);	# OP_I_ADD
    local($x -= 1);	# OP_I_SUBTRACT
}
local($x?$y:$z) = 1;	# OP_COND_EXPR		ok
# these two are fatal run-time errors instead
#local(@$a);		# OP_RV2AV		ok
#local(%$a);		# OP_RV2HV		ok
local(*a);		# OP_RV2GV		ok
local(@a[1,2]);		# OP_ASLICE		ok
local(@a{1,2});		# OP_HSLICE		ok
local(@a = (1,2));	# OP_AASSIGN
local($$x);		# OP_RV2SV		ok
local($#a);		# OP_AV2ARYLEN
local($x =   1);	# OP_SASSIGN
local($x &&= 1);	# OP_ANDASSIGN
local($x ||= 1);	# OP_ORASSIGN
local($x //= 1);	# OP_DORASSIGN
local($a[0]);		# OP_AELEMFAST		ok

local(substr($x,0,1));	# OP_SUBSTR
local(pos($x));		# OP_POS
local(vec($x,0,1));	# OP_VEC
local($a[$b]);		# OP_AELEM		ok
local($a{$b});		# OP_HELEM		ok
local($[);		# OP_CONST

no warnings 'syntax';
EXPECT
Useless localization of subroutine entry at - line 10.
Useless localization of exponentiation (**) at - line 11.
Useless localization of multiplication (*) at - line 12.
Useless localization of division (/) at - line 13.
Useless localization of modulus (%) at - line 14.
Useless localization of repeat (x) at - line 15.
Useless localization of addition (+) at - line 16.
Useless localization of subtraction (-) at - line 17.
Useless localization of concatenation (.) or string at - line 18.
Useless localization of left bitshift (<<) at - line 19.
Useless localization of right bitshift (>>) at - line 20.
Useless localization of bitwise and (&) at - line 21.
Useless localization of bitwise xor (^) at - line 22.
Useless localization of bitwise or (|) at - line 23.
Useless localization of integer multiplication (*) at - line 26.
Useless localization of integer division (/) at - line 27.
Useless localization of integer modulus (%) at - line 28.
Useless localization of integer addition (+) at - line 29.
Useless localization of integer subtraction (-) at - line 30.
Useless localization of list assignment at - line 39.
Useless localization of array length at - line 41.
Useless localization of scalar assignment at - line 42.
Useless localization of logical and assignment (&&=) at - line 43.
Useless localization of logical or assignment (||=) at - line 44.
Useless localization of defined or assignment (//=) at - line 45.
Useless localization of substr at - line 48.
Useless localization of match position at - line 49.
Useless localization of vec at - line 50.
########
# op.c
use warnings 'deprecated';
my $x1 if 0;
my @x2 if 0;
my %x3 if 0;
my ($x4) if 0;
my ($x5,@x6, %x7) if 0;
0 && my $z1;
0 && my (%z2);
# these shouldn't warn
our $x if 0;
our $x unless 0;
if (0) { my $w1 }
if (my $w2) { $a=1 }
if ($a && (my $w3 = 1)) {$a = 2}

EXPECT
Deprecated use of my() in false conditional at - line 3.
Deprecated use of my() in false conditional at - line 4.
Deprecated use of my() in false conditional at - line 5.
Deprecated use of my() in false conditional at - line 6.
Deprecated use of my() in false conditional at - line 7.
Deprecated use of my() in false conditional at - line 8.
Deprecated use of my() in false conditional at - line 9.