Flaggify — Create flags of countries and subdivisions (Bash package)

echo "The flag of Canada (CA) is widely known." | flaggify r
flaggify r  <<< "She thinks GB-WLS's flag looks nicer than GB-ENG's."
flaggify r "Flags of CH and VA are 1:1, and NP's isn't rectangular."

echo CA | flaggify t     #⇒ 🇨🇦
flaggify t <<< AQGL      #⇒ 🇦🇶🇬🇱
flaggify t CHVANP        #⇒ 🇨🇭🇻🇦🇳🇵

echo gbsct | flaggify s  #⇒ 🏴󠁧󠁢󠁳󠁣󠁴󠁿
echo US-SC | flaggify s  #⇒ 🏴󠁵󠁳󠁳󠁣󠁿
flaggify s CA-QC         #⇒ 🏴󠁣󠁡󠁱󠁣󠁿

#!/usr/bin/env bash

# Flaggify --- Create flags of countries and subdivisions

# SPDX-FileCopyrightText: © flandrew <https://flandrew.srht.site/listful>
# SPDX-License-Identifier: GPL-3.0-or-later

#---------------------#
# Author:  flandrew   #
# Created: 2024-04-24 #
# Updated: 2025-10-31 #
#---------------------#
# Version: 0.2.0      #
#---------------------#

### Commentary
#
# You'll want to have some font capable of displaying emoji flags.
#
#############################################################################

### Code

# REPLACE in string

declare -a F
F=(GB-ENG 🏴󠁧󠁢󠁥󠁮󠁧󠁿   GB-SCT 🏴󠁧󠁢󠁳󠁣󠁴󠁿   GB-WLS 🏴󠁧󠁢󠁷󠁬󠁳󠁿

   AC 🇦🇨   AD 🇦🇩   AE 🇦🇪   AF 🇦🇫   AG 🇦🇬   AI 🇦🇮   AL 🇦🇱   AM 🇦🇲   AO 🇦🇴
   AQ 🇦🇶   AR 🇦🇷   AS 🇦🇸   AT 🇦🇹   AU 🇦🇺   AW 🇦🇼   AX 🇦🇽   AZ 🇦🇿   BA 🇧🇦
   BB 🇧🇧   BD 🇧🇩   BE 🇧🇪   BF 🇧🇫   BG 🇧🇬   BH 🇧🇭   BI 🇧🇮   BJ 🇧🇯   BL 🇧🇱
   BM 🇧🇲   BN 🇧🇳   BO 🇧🇴   BQ 🇧🇶   BR 🇧🇷   BS 🇧🇸   BT 🇧🇹   BV 🇧🇻   BW 🇧🇼
   BY 🇧🇾   BZ 🇧🇿   CA 🇨🇦   CC 🇨🇨   CD 🇨🇩   CF 🇨🇫   CG 🇨🇬   CH 🇨🇭   CI 🇨🇮
   CK 🇨🇰   CL 🇨🇱   CM 🇨🇲   CN 🇨🇳   CO 🇨🇴   CP 🇨🇵   CR 🇨🇷   CU 🇨🇺   CV 🇨🇻
   CW 🇨🇼   CX 🇨🇽   CY 🇨🇾   CZ 🇨🇿   DE 🇩🇪   DG 🇩🇬   DJ 🇩🇯   DK 🇩🇰   DM 🇩🇲
   DO 🇩🇴   DZ 🇩🇿   EA 🇪🇦   EC 🇪🇨   EE 🇪🇪   EG 🇪🇬   EH 🇪🇭   ER 🇪🇷   ES 🇪🇸
   ET 🇪🇹   EU 🇪🇺   FI 🇫🇮   FJ 🇫🇯   FK 🇫🇰   FM 🇫🇲   FO 🇫🇴   FR 🇫🇷   GA 🇬🇦
   GB 🇬🇧   GD 🇬🇩   GE 🇬🇪   GF 🇬🇫   GG 🇬🇬   GH 🇬🇭   GI 🇬🇮   GL 🇬🇱   GM 🇬🇲
   GN 🇬🇳   GP 🇬🇵   GQ 🇬🇶   GR 🇬🇷   GS 🇬🇸   GT 🇬🇹   GU 🇬🇺   GW 🇬🇼   GY 🇬🇾
   HK 🇭🇰   HM 🇭🇲   HN 🇭🇳   HR 🇭🇷   HT 🇭🇹   HU 🇭🇺   IC 🇮🇨   ID 🇮🇩   IE 🇮🇪
   IL 🇮🇱   IM 🇮🇲   IN 🇮🇳   IO 🇮🇴   IQ 🇮🇶   IR 🇮🇷   IS 🇮🇸   IT 🇮🇹   JE 🇯🇪
   JM 🇯🇲   JO 🇯🇴   JP 🇯🇵   KE 🇰🇪   KG 🇰🇬   KH 🇰🇭   KI 🇰🇮   KM 🇰🇲   KN 🇰🇳
   KP 🇰🇵   KR 🇰🇷   KW 🇰🇼   KY 🇰🇾   KZ 🇰🇿   LA 🇱🇦   LB 🇱🇧   LC 🇱🇨   LI 🇱🇮
   LK 🇱🇰   LR 🇱🇷   LS 🇱🇸   LT 🇱🇹   LU 🇱🇺   LV 🇱🇻   LY 🇱🇾   MA 🇲🇦   MC 🇲🇨
   MD 🇲🇩   ME 🇲🇪   MF 🇲🇫   MG 🇲🇬   MH 🇲🇭   MK 🇲🇰   ML 🇲🇱   MM 🇲🇲   MN 🇲🇳
   MO 🇲🇴   MP 🇲🇵   MQ 🇲🇶   MR 🇲🇷   MS 🇲🇸   MT 🇲🇹   MU 🇲🇺   MV 🇲🇻   MW 🇲🇼
   MX 🇲🇽   MY 🇲🇾   MZ 🇲🇿   NA 🇳🇦   NC 🇳🇨   NE 🇳🇪   NF 🇳🇫   NG 🇳🇬   NI 🇳🇮
   NL 🇳🇱   NO 🇳🇴   NP 🇳🇵   NR 🇳🇷   NU 🇳🇺   NZ 🇳🇿   OM 🇴🇲   PA 🇵🇦   PE 🇵🇪
   PF 🇵🇫   PG 🇵🇬   PH 🇵🇭   PK 🇵🇰   PL 🇵🇱   PM 🇵🇲   PN 🇵🇳   PR 🇵🇷   PS 🇵🇸
   PT 🇵🇹   PW 🇵🇼   PY 🇵🇾   QA 🇶🇦   RE 🇷🇪   RO 🇷🇴   RS 🇷🇸   RU 🇷🇺   RW 🇷🇼
   SA 🇸🇦   SB 🇸🇧   SC 🇸🇨   SD 🇸🇩   SE 🇸🇪   SG 🇸🇬   SH 🇸🇭   SI 🇸🇮   SJ 🇸🇯
   SK 🇸🇰   SL 🇸🇱   SM 🇸🇲   SN 🇸🇳   SO 🇸🇴   SR 🇸🇷   SS 🇸🇸   ST 🇸🇹   SV 🇸🇻
   SX 🇸🇽   SY 🇸🇾   SZ 🇸🇿   TA 🇹🇦   TC 🇹🇨   TD 🇹🇩   TF 🇹🇫   TG 🇹🇬   TH 🇹🇭
   TJ 🇹🇯   TK 🇹🇰   TL 🇹🇱   TM 🇹🇲   TN 🇹🇳   TO 🇹🇴   TR 🇹🇷   TT 🇹🇹   TV 🇹🇻
   TW 🇹🇼   TZ 🇹🇿   UA 🇺🇦   UG 🇺🇬   UM 🇺🇲   UN 🇺🇳   US 🇺🇸   UY 🇺🇾   UZ 🇺🇿
   VA 🇻🇦   VC 🇻🇨   VE 🇻🇪   VG 🇻🇬   VI 🇻🇮   VN 🇻🇳   VU 🇻🇺   WF 🇼🇫   WS 🇼🇸
   XK 🇽🇰   YE 🇾🇪   YT 🇾🇹   ZA 🇿🇦   ZM 🇿🇲   ZW 🇿🇼)

# Replace with flags all code matches in string — by looking up array above.
sed-expr() { printf 's/\\b%s\\b/%s/g;' "${F[@]}" ;}
f-string() { sed -E "$(sed-expr)" <<< "$1"       ;}

#############################################################################
# TERRITORY conversion

# Convert every letter (assumed upcase) to corresponding regional indicator.
# This happens directly — no lookups. Pairs become flags (whenever existing).
f-territ()
while read -N1 -r c
do : "$(printf "$c" | od -An -t x1)"
   : "$(printf "%X" "$((0xa5 + 0x${_// }))")"
   printf "\U1F1$_"
done < <(printf "$1")

#############################################################################
# SUBDIVISION conversion

# Downcase and convert every letter to corresponding tag letter.
# This happens directly — no lookups.
taggify()
while read -N1 -r c
do : "$(printf "$c" | od -An -t x1)"
   printf "\UE00${_// }"
done < <(printf "${1,,}" | tr -d -)

# Then wrap it with waving black flag and cancel flag.
f-subdiv() { printf "\U1F3F4$(taggify "$1")\UE007F" ;}

#############################################################################

usage() { local p="$(basename "${BASH_SOURCE[0]}")"
          less <<EOU
NAME
  $p --- Create flags of countries and subdivisions

SYNOPSIS
  $p r [STRING]
  $p t [STRING]
  $p s [STRING]

  If STRING is not passed, read from stdin.

DESCRIPTION
  The three operations above are: "replace", "territory", and "subdivision".

  - REPLACE looks for pairs of uppercase letters in a string and, assuming
    they refer to country codes, replace them with the corresponding flags if
    the countries exist: we look that up in an array.

    It also accepts England, Scotland, and Wales.

  - TERRITORY directly converts every letter (which must be upcased) to its
    corresponding regional indicator. Each pair of regional indicators is
    rendered as a flag whenever the corresponding territory exists.

    A territory is typically a "country", with some exceptions (e.g. EU → 🇪🇺).

    No newlines are added to the end of the result.

  - SUBDIVISION directly converts every letter to its corresponding lowercase
    tag letter. This is then wrapped with a "waving black flag" and a "cancel
    tag". All this is displayed as subdivision flag, provided you have a font
    that supports it.

    No newlines are added to the end of the result.

  REPLACE

    Either these:
      echo "The flag of Canada (CA) is widely known."             | $p r
      echo "She thinks GB-WLS's flag looks nicer than GB-ENG's."  | $p r
      $p r <<< "Flags of CH and VA are 1:1, and NP's isn't rectangular."

    or these:
      $p r "The flag of Canada (CA) is widely known."
      $p r "She thinks GB-WLS's flag looks nicer than GB-ENG's."
      $p r "Flags of CH and VA are 1:1, and NP's isn't rectangular."

    should equally output:
      The flag of Canada (🇨🇦) is widely known.
      She thinks 🏴󠁧󠁢󠁷󠁬󠁳󠁿's flag looks nicer than 🏴󠁧󠁢󠁥󠁮󠁧󠁿's.
      Flags of 🇨🇭 and 🇻🇦 are 1:1, and 🇳🇵's isn't rectangular.

  TERRITORY

    Either these:
      echo CA     | $p t
      echo CHVANP | $p t

    or these:
      $p t CA
      $p t CHVANP

    should equally output:
      🇨🇦
      🇨🇭🇻🇦🇳🇵

  SUBDIVISION

    Either these:
      echo gbsct | $p s
      echo US-SC | $p s
      echo CA-QC | $p s

    or these:
      $p s gbsct
      $p s US-SC
      $p s CA-QC

    should equally output:
      🏴󠁧󠁢󠁳󠁣󠁴󠁿
      🏴󠁵󠁳󠁳󠁣󠁿
      🏴󠁣󠁡󠁱󠁣󠁿
EOU
          exit "${1:-0}" ;}

#############################################################################

main () { case "$1" in
              r) : f-string ;;
              t) : f-territ ;;
              s) : f-subdiv ;;
              h) usage 0    ;;
              *) usage 1    ;;
          esac
          "$_" "${2:-$(</dev/stdin)}" ;}

#############################################################################

main "$@"
exit 0