#!/bin/bash
#
# setcode -- Markus Kuhn <mgk25@cl.cam.ac.uk> 2001-07-31 -- share and enjoy
#
# Adjust the character set of the terminal according to current locale
# by sending the appropriate ISO 2022 sequence to stdout.
#
# Usage:
#
#   First set LANG or LC_CTYPE to the desired locale, then call this
#   script to inform your terminal/tty about the current encoding.
#
# Health warning:
#
#   Long exposure to ISO 2022 can cause states of permanent
#   head damage. Better lock your terminal to UTF-8 forever
#   and use UTF-8 exclusively!
#
# References:
#
#   - ISO 2022 = ECMA-35, http://www.ecma.ch/ecma1/STAND/ECMA-035.HTM
#   - http://www.itscj.ipsj.or.jp/ISO-IR/
#   - Ken Lunde: CJKV Information Processing. O'Reilly, 1999
#
charmap=$(locale charmap)
# Select coding system
case $charmap in
  UTF-8 )
    echo -ne '\033%G'
    exit ;;
  *)
    # return to ISO 2022 and set G0 = US-ASCII
    echo -ne '\033%@\033(B' ;;
esac
# G0-G3 Designators
case $charmap in
  ASCII | US-ASCII | ANSI_X3\.4-1968 | 646 | ISO646 | ISO_646.IRV | \
  ISO2022* | ISO-2022* )
    ;;
  ISO8859-1 | ISO-8859-1 ) 
    echo -ne '\033-A' ;;
  ISO8859-2 | ISO-8859-2 ) 
    echo -ne '\033-B' ;;
  ISO8859-3 | ISO-8859-3 ) 
    echo -ne '\033-C' ;;
  ISO8859-4 | ISO-8859-4 ) 
    echo -ne '\033-D' ;;
  ISO8859-5 | ISO-8859-5 ) 
    echo -ne '\033-L' ;;
  ISO8859-6 | ISO-8859-6 ) 
    echo -ne '\033-G' ;;
  ISO8859-7 | ISO-8859-7 ) 
    echo -ne '\033-F' ;;
  ISO8859-8 | ISO-8859-8 ) 
    echo -ne '\033-H' ;;
  ISO8859-9 | ISO-8859-9 ) 
    echo -ne '\033-M' ;;
  ISO8859-10 | ISO-8859-10 ) 
    echo -ne '\033-V' ;;
  ISO8859-11 | ISO-8859-11 ) 
    echo -ne '\033-T' ;;
  ISO8859-13 | ISO-8859-13 ) 
    echo -ne '\033-Y' ;;
  ISO8859-14 | ISO-8859-14 ) 
    echo -ne '\033-_' ;;
  ISO8859-15 | ISO-8859-15 ) 
    echo -ne '\033-b' ;;
  ISO8859-16 | ISO-8859-16 )
    echo -ne '\033-f' ;;
  EUC-CN )
    # G1DM4: GB 2312-80 = ISO IR 58
    echo -ne '\033$)A' ;;
  EUC-JP )
    # G1DM4: JIS X 0208-1990 = ISO IR 87/168
    # G2D4:  JIS X 0201-1997 = ISO IR 13
    # G3DM4: JIS X 0212-1990 = ISO IR 159
    echo -ne '\033$)B\033)I\033$+D' ;;
  EUC-KR )
    # G1DM4: KS X 1001:1992 = KSC 5601-1987 = ISO IR 149
    echo -ne '\033$)C' ;;
  EUC-TW )
    # G1DM4: CNS 11643-1992 Plane 1 = ISO IR 171
    # G2DM4: CNS 11643-1992 Planes 1-7 = ISO IR ???
    echo -ne '\033$)G'
    echo 'Warning: no ESC sequence for designating G2 in EUC-TW known!' 1>&2 ;;
  TIS-620 | TIS620.2533 )
    # G1D6: TIS 620-2533 (1990) = ISO IR 166
    echo -ne '\033-T' ;;
  VSCII )
    # G1D6: TCVN 5712-1993 (VSCII) = ISO IR 180
    echo -ne '\033-Z' ;;
  GB18030 | GBK | BIG5 | Big5 | KOI8-R )
    echo 'Character map '$charmap' not ISO registered and not supported' 1>&2
    exit 1 ;;
  * )
    echo 'Character map '$charmap' not known' 1>&2
    exit 1 ;;
esac
# Announce code structure facilities
# This is needed to tell the terminal, what kind of ISO 2022 facilities it
# can use in the characters that it sends back. This setting is only valid
# until the terminal receives another G0-G3 designation or 'ESC %' sequence.
case $charmap in
  ASCII | US-ASCII | ANSI_X3\.4-1968 | 646 | ISO646 | ISO_646.IRV )
    # ACS 1: GL=G0, no shifts
    echo -ne '\033 A' ;;
  ISO8859-* | ISO-8859-* | TIS-620 | TIS620.2533 | VSCII )
    # ACS 3: GL=G0, GR=G1, no shifts
    echo -ne '\033 C' ;;
  EUC-* )
    # ACS 28: Use SS2 (0x8e) and SS3 (0x8f) followed by GR codes only
    echo -ne '\033 \\' ;;
  ISO-2022-* | ISO2022-* )
    # ACS 10: Use 7-bit characters only (but allow redesignation and shifts)
    echo -ne '\033 J' ;;
esac