regcomp

source of perl for linux application,

  regcomp.c	AOK

  Quantifier unexpected on zero-length expression [S_study_chunk] 

  Useless (%s%c) - %suse /%c modifier [S_reg] 
  Useless (%sc) - %suse /gc modifier [S_reg] 



  Strange *+?{} on zero-length expression	[S_study_chunk]
	/(?=a)?/

  %.*s matches null string many times   	[S_regpiece]
	$a = "ABC123" ; $a =~ /(?=a)*/'

  /%.127s/: Unrecognized escape \\%c passed through	[S_regatom] 
  	$x = '\m' ; /$x/

  POSIX syntax [%c %c] belongs inside character classes	[S_checkposixcc] 


  Character class [:%.*s:] unknown	[S_regpposixcc]

  Character class syntax [%c %c] belongs inside character classes [S_checkposixcc] 
  
  /%.127s/: false [] range \"%*.*s\" in regexp [S_regclass]

  /%.127s/: false [] range \"%*.*s\" in regexp [S_regclassutf8]

  /%.127s/: Unrecognized escape \\%c in character class passed through"	[S_regclass] 

  /%.127s/: Unrecognized escape \\%c in character class passed through"	[S_regclassutf8] 

  False [] range \"%*.*s\" [S_regclass]

__END__
# regcomp.c [S_regpiece]
use warnings 'regexp' ;
my $a = "ABC123" ; 
$a =~ /(?=a)*/ ;
no warnings 'regexp' ;
$a =~ /(?=a)*/ ;
EXPECT
(?=a)* matches null string many times in regex; marked by <-- HERE in m/(?=a)* <-- HERE / at - line 4.
########
# regcomp.c [S_regatom]
$x = '\m' ;
use warnings 'regexp' ;
$a =~ /a$x/ ;
no warnings 'regexp' ;
$a =~ /a$x/ ;
EXPECT
Unrecognized escape \m passed through in regex; marked by <-- HERE in m/a\m <-- HERE / at - line 4.
########
# regcomp.c [S_regatom]
# The \q should warn, the \_ should NOT warn.
use warnings 'regexp';
"foo" =~ /\q/;
"bar" =~ /\_/;
no warnings 'regexp';
"foo" =~ /\q/;
"bar" =~ /\_/;
EXPECT
Unrecognized escape \q passed through in regex; marked by <-- HERE in m/\q <-- HERE / at - line 4.
########
# regcomp.c [S_regpposixcc S_checkposixcc]
#
use warnings 'regexp' ;
$_ = "" ;
/[:alpha:]/;
/[:zog:]/;
no warnings 'regexp' ;
/[:alpha:]/;
/[:zog:]/;
EXPECT
POSIX syntax [: :] belongs inside character classes in regex; marked by <-- HERE in m/[:alpha:] <-- HERE / at - line 5.
POSIX syntax [: :] belongs inside character classes in regex; marked by <-- HERE in m/[:zog:] <-- HERE / at - line 6.
########
# regcomp.c [S_checkposixcc]
#
use warnings 'regexp' ;
$_ = "" ;
/[.zog.]/;
no warnings 'regexp' ;
/[.zog.]/;
EXPECT
POSIX syntax [. .] belongs inside character classes in regex; marked by <-- HERE in m/[.zog.] <-- HERE / at - line 5.
POSIX syntax [. .] is reserved for future extensions in regex; marked by <-- HERE in m/[.zog.] <-- HERE / at - line 5.
########
# regcomp.c [S_regclass]
$_ = "";
use warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
no warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
EXPECT
False [] range "a-\d" in regex; marked by <-- HERE in m/[a-\d <-- HERE ]/ at - line 5.
False [] range "\d-" in regex; marked by <-- HERE in m/[\d- <-- HERE b]/ at - line 6.
False [] range "\s-" in regex; marked by <-- HERE in m/[\s- <-- HERE \d]/ at - line 7.
False [] range "\d-" in regex; marked by <-- HERE in m/[\d- <-- HERE \s]/ at - line 8.
False [] range "a-[:digit:]" in regex; marked by <-- HERE in m/[a-[:digit:] <-- HERE ]/ at - line 9.
False [] range "[:digit:]-" in regex; marked by <-- HERE in m/[[:digit:]- <-- HERE b]/ at - line 10.
False [] range "[:alpha:]-" in regex; marked by <-- HERE in m/[[:alpha:]- <-- HERE [:digit:]]/ at - line 11.
False [] range "[:digit:]-" in regex; marked by <-- HERE in m/[[:digit:]- <-- HERE [:alpha:]]/ at - line 12.
########
# regcomp.c [S_regclassutf8]
BEGIN {
    if (ord("\t") == 5) {
        print "SKIPPED\n# ebcdic regular expression ranges differ.";
        exit 0;
    }
}
use utf8;
$_ = "";
use warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
no warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
EXPECT
False [] range "a-\d" in regex; marked by <-- HERE in m/[a-\d <-- HERE ]/ at - line 12.
False [] range "\d-" in regex; marked by <-- HERE in m/[\d- <-- HERE b]/ at - line 13.
False [] range "\s-" in regex; marked by <-- HERE in m/[\s- <-- HERE \d]/ at - line 14.
False [] range "\d-" in regex; marked by <-- HERE in m/[\d- <-- HERE \s]/ at - line 15.
False [] range "a-[:digit:]" in regex; marked by <-- HERE in m/[a-[:digit:] <-- HERE ]/ at - line 16.
False [] range "[:digit:]-" in regex; marked by <-- HERE in m/[[:digit:]- <-- HERE b]/ at - line 17.
False [] range "[:alpha:]-" in regex; marked by <-- HERE in m/[[:alpha:]- <-- HERE [:digit:]]/ at - line 18.
False [] range "[:digit:]-" in regex; marked by <-- HERE in m/[[:digit:]- <-- HERE [:alpha:]]/ at - line 19.
########
# regcomp.c [S_regclass S_regclassutf8]
use warnings 'regexp' ;
$a =~ /[a\zb]/ ;
no warnings 'regexp' ;
$a =~ /[a\zb]/ ;
EXPECT
Unrecognized escape \z in character class passed through in regex; marked by <-- HERE in m/[a\z <-- HERE b]/ at - line 3.

########
# regcomp.c [S_reg]
use warnings 'regexp' ;
$a = qr/(?c)/;
$a = qr/(?-c)/;
$a = qr/(?g)/;
$a = qr/(?-g)/;
$a = qr/(?o)/;
$a = qr/(?-o)/;
$a = qr/(?g-o)/;
$a = qr/(?g-c)/;
$a = qr/(?o-cg)/;  # (?c) means (?g) error won't be thrown
$a = qr/(?ogc)/;
no warnings 'regexp' ;
$a = qr/(?c)/;
$a = qr/(?-c)/;
$a = qr/(?g)/;
$a = qr/(?-g)/;
$a = qr/(?o)/;
$a = qr/(?-o)/;
$a = qr/(?g-o)/;
$a = qr/(?g-c)/;
$a = qr/(?o-cg)/;  # (?c) means (?g) error won't be thrown
$a = qr/(?ogc)/;
#EXPECT
EXPECT
Useless (?c) - use /gc modifier in regex; marked by <-- HERE in m/(?c <-- HERE )/ at - line 3.
Useless (?-c) - don't use /gc modifier in regex; marked by <-- HERE in m/(?-c <-- HERE )/ at - line 4.
Useless (?g) - use /g modifier in regex; marked by <-- HERE in m/(?g <-- HERE )/ at - line 5.
Useless (?-g) - don't use /g modifier in regex; marked by <-- HERE in m/(?-g <-- HERE )/ at - line 6.
Useless (?o) - use /o modifier in regex; marked by <-- HERE in m/(?o <-- HERE )/ at - line 7.
Useless (?-o) - don't use /o modifier in regex; marked by <-- HERE in m/(?-o <-- HERE )/ at - line 8.
Useless (?g) - use /g modifier in regex; marked by <-- HERE in m/(?g <-- HERE -o)/ at - line 9.
Useless (?-o) - don't use /o modifier in regex; marked by <-- HERE in m/(?g-o <-- HERE )/ at - line 9.
Useless (?g) - use /g modifier in regex; marked by <-- HERE in m/(?g <-- HERE -c)/ at - line 10.
Useless (?-c) - don't use /gc modifier in regex; marked by <-- HERE in m/(?g-c <-- HERE )/ at - line 10.
Useless (?o) - use /o modifier in regex; marked by <-- HERE in m/(?o <-- HERE -cg)/ at - line 11.
Useless (?-c) - don't use /gc modifier in regex; marked by <-- HERE in m/(?o-c <-- HERE g)/ at - line 11.
Useless (?o) - use /o modifier in regex; marked by <-- HERE in m/(?o <-- HERE gc)/ at - line 12.
Useless (?g) - use /g modifier in regex; marked by <-- HERE in m/(?og <-- HERE c)/ at - line 12.
Useless (?c) - use /gc modifier in regex; marked by <-- HERE in m/(?ogc <-- HERE )/ at - line 12.