regexp_dotno

#! /usr/bin/env bash

SOURCE_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

#
#  For usage, see ./test_regexp
#

# Source https://www.norid.no/en/regelverk/navnepolitikk/#link3
# Verified 2018-12-11
# The lines below prefixed with #* are read by the code in 
# mcn-source-simple/permutate
# Name of letter        Unicode  Name of letter        Unicode
#* a with acute accent á 00E1*    o with acute accent ó 00F3*
#* a with grave accent à 00E0*    o with grave accent ò 00F2*
#* a with umlaut       ä 00E4*    o with circumflex   ô 00F4*
#* c with caron        č 010D*    o with umlaut       ö 00F6*
#* c with cedilla      ç 00E7*    s with caron        š 0161*
#* d with crossbar     đ 0111*    t with crossbar     ŧ 0167*
#* e with acute accent é 00E9*    u with umlaut       ü 00FC*
#* e with grave accent è 00E8*    z with caron        ž 017E*
#* e with circumflex   ê 00EA*    æ                   æ 00E6*
#* i with umlaut       ï 00EF*    ø                   ø 00F8*
#* ENG                 ŋ 014B*    å                   å 00E5*
#* n with acute accent ń 0144*    n with tilde        ñ 00F1*

VCHAR_EX_DASH='[a-z0-9\x{E0}\x{E1}\x{E4}\x{E5}\x{E6}\x{E7}\x{E8}\x{E9}\x{EA}\x{EF}\x{F1}\x{F2}\x{F3}\x{F4}\x{F6}\x{F8}\x{FC}\x{10D}\x{111}\x{144}\x{14B}\x{161}\x{167}\x{17E}]'

# All valid category domains
CAT_DOMAINS=$(${SOURCE_DIR}/cat_domains_to_regexp)
EXP_REGEXP=$(cat <<'EOF'
(
  (?:
    # $x are all valid chars except - (hyphen)
    # A normal domain, min 2 chars (neither -) with 0-61 chars (incl. -) in between
    $x(?:$x|-){0,61}$x
    |
    # $y are all category domain surrounded by (?:...)
    # valid: x.<cat>.no and xx.<cat>.no, but not -.<cat>.no, -x.<cat>.no or x-.<cat>.no
    (?:
      $x
      |
      $x(?:$x|-){0,61}$x
    )\.$y
  )
  \.no
)
(?!$x)
EOF
)

# Remove comments, spaces and newlines from regexp
REGEXP="$(echo "$EXP_REGEXP" | sed -e 's/#.*$//' -e 's/ //g' | tr -d '\n')"

if [ -t 0 ] ; then 
  if [ "$#" -ne 1 ]; then
    echo "No STDIN input detected (non-terminal), and no file argument supplied"
    exit 1;
  fi
  perl -CSD -e "open my \$in, \"$1\"; while(<\$in>) { \$x=qr/${VCHAR_EX_DASH}/i; \$y=qr/(?:${CAT_DOMAINS})/i; while(/${REGEXP}/gi) { print \$1,\"\\n\"; } } close(\$in);"
else
  perl -CSD -ne "BEGIN { \$x=qr/${VCHAR_EX_DASH}/i; \$y=qr/(?:${CAT_DOMAINS})/i; } while(/${REGEXP}/goi) { print \$1,\"\\n\"; }"
fi