Test IPv6 regular expression without dependency on custom scripts

ipv6-regex-test.sh

#!/bin/sh
#

test_regex () {
  REGEX="$1";
  TEST_STRINGS="$2";
  [ -n "$3" ] && [ "$3" = "expect_no_match" ] && SHOW_NON_MATCHING="-v";

  # find IP addresses anywhere in the string
  # but avoid certain characters in the beginning and end
  # so we don't get partial matches like
  # 1.2.3.4 in 1.2.3.4.5.
  # but we can match comma delimited strings like
  # 1.2.3.4,6.7.8.9
  BEGIN_REGEX='(?<![a-zA-Z0-9:.])'
  END_REGEX='(?![a-zA-Z0-9:.%])'
  # test regex on strings and
  # color code pass and fail messages
  matches=`echo "$TEST_STRINGS" \
   |grep -C 10000 --label=test -H -P $SHOW_NON_MATCHING "${BEGIN_REGEX}(${REGEX})$END_REGEX" \
   |sed -e ''/test:/s//\`printf "\033[32mpass\033[0m--"\`/'' -e ''/test-/s//\`printf "\033[32mfail\033[0m--"\`/''`
   echo "$matches"
}

#test strings expected to match the IPV4 regex
RE_IPV4="((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])"
IPV4_TEST_STRINGS=`cat <<EOF
127.0.0.1
10.0.0.1
192.168.1.1
0.0.0.0
255.255.255.255
EOF`

results=`test_regex "$RE_IPV4" "$IPV4_TEST_STRINGS"`

echo "IPV4 Positive Test Cases:"
echo "$results"
echo

# test strings expected not to match the IPV4 regex
IPV4_NEG_TEST_STRINGS=`cat <<EOF
10002.3.4
1.2.3.4.5
256.0.0.0
260.0.0.0
EOF`

results=`test_regex "$RE_IPV4" "${IPV4_NEG_TEST_STRINGS}" "expect_no_match"`

echo "IPV4 Negative Test Cases (expected not to match the regex):"
echo "$results"
echo
#IPV6 tests
SEG="[0-9a-fA-F]{1,4}"

RE_IPV6="(${SEG}:){7,7}${SEG}|"                              # TEST: 1:2:3:4:5:6:7:8
RE_IPV6="${RE_IPV6}(${SEG}:){1,7}:|"                         # TEST: 1::                              1:2:3:4:5:6:7::
RE_IPV6="${RE_IPV6}(${SEG}:){1,6}:${SEG}|"                   # TEST: 1::8             1:2:3:4:5:6::8  1:2:3:4:5:6::8
RE_IPV6="${RE_IPV6}(${SEG}:){1,5}(:${SEG}){1,2}|"            # TEST: 1::7:8           1:2:3:4:5::7:8  1:2:3:4:5::8
RE_IPV6="${RE_IPV6}(${SEG}:){1,4}(:${SEG}){1,3}|"            # TEST: 1::6:7:8         1:2:3:4::6:7:8  1:2:3:4::8
RE_IPV6="${RE_IPV6}(${SEG}:){1,3}(:${SEG}){1,4}|"            # TEST: 1::5:6:7:8       1:2:3::5:6:7:8  1:2:3::8
RE_IPV6="${RE_IPV6}(${SEG}:){1,2}(:${SEG}){1,5}|"            # TEST: 1::4:5:6:7:8     1:2::4:5:6:7:8  1:2::8
RE_IPV6="${RE_IPV6}${SEG}:((:${SEG}){1,6})|"                 # TEST: 1::3:4:5:6:7:8   1::3:4:5:6:7:8  1::8
RE_IPV6="${RE_IPV6}:((:${SEG}){1,7}|:)|"                     # TEST: ::2:3:4:5:6:7:8  ::2:3:4:5:6:7:8 ::8       ::
RE_IPV6="${RE_IPV6}fe08:(:${SEG}){2,2}%[0-9a-zA-Z]{1,}|"     # TEST: fe08::7:8%eth0      fe08::7:8%1                                      (link-local IPv6 addresses with zone index)
RE_IPV6="${RE_IPV6}::(ffff(:0{1,4})?:)?${RE_IPV4}|"          # TEST: ::255.255.255.255   ::ffff:255.255.255.255  ::ffff:0:255.255.255.255 (IPv4-mapped IPv6 addresses and IPv4-translated addresses)
RE_IPV6="${RE_IPV6}(${SEG}:){1,4}:${RE_IPV4}"                # TEST: 2001:db8:3:4::192.0.2.33  64:ff9b::192.0.2.33                        (IPv4-Embedded IPv6 Address)

#IPV6 positive test strings
IPV6_TEST_STRINGS=`cat <<EOF
1:2:3:4:5:6:7:8
::ffff:10.0.0.1
::ffff:1.2.3.4
::ffff:0.0.0.0
1:2:3:4:5:6:77:88
::ffff:255.255.255.255
fe08::7:8
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
`
results=`test_regex "$RE_IPV6" "$IPV6_TEST_STRINGS"`

echo "IPV6 Test Cases:"
echo "$results"
echo

IPV6_NEG_TEST_STRINGS=`cat <<EOF
1:2:3:4:5:6:7:8:9
1:2:3:4:5:6::7:8
:1:2:3:4:5:6:7:8
1:2:3:4:5:6:7:8:
::1:2:3:4:5:6:7:8
1:2:3:4:5:6:7:8::
1:2:3:4:5:6:7:88888
2001:db8:3:4:5::192.0.2.33
fe08::7:8%
fe08::7:8i
fe08::7:8interface
`
results=`test_regex "$RE_IPV6" "$IPV6_NEG_TEST_STRINGS" "expect_no_match"`

echo "IPV4 Negative Test Cases (expected not to match the regex):"
echo "$results"