Differences between revisions 28 and 29
⇤ ← Revision 28 as of 2012-01-08 21:07:32 →
Size: 24037
Editor: dethrophes
Comment: I added some simple test cases and discovered some weird bash behaviour, whihc I've reported as a bug. But I've added a workaround these functions.
← Revision 29 as of 2012-01-09 07:07:48 → ⇥
Size: 23318
Editor: dethrophes
Comment: replaced periods in function names with underscores(POSIX compliance). use C.UTF-8 instead of the en_US.UTF-8
Deletions are marked like this. Additions are marked like this.
Line 12: Line 12:
   echo -n "$ExpandedString"                       echo -n "$ExpandedString"
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Another approach `$'...'` strings are escaped before evaluation and can be embedded directly in code.  Another approach `$'...'` strings are escaped before evaluation and can be embedded directly in code.
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{{{
        ###############################################################
        #
       # Note about Ext Ascii and UTF-8 encoding
        #
       # for values 0x00 - 0x7f Identical
       # for values 0x80 - 0xff conflict between UTF-8 & ExtAscii
       # for values 0x100 - 0xffff Only UTF-8 UTF-16 UTF-32
       # for values 0x100 - 0x7FFFFFFF Only UTF-8 UTF-32
        #
       # value EAscii UTF-8 UTF-16 UTF-32
        # 0x20 "\x20" "\x20" \u0020 \U00000020
        # 0x20 "\x7f" "\x7f" \u007f \U0000007f
        # 0x80 "\x80" "\xc2\x80" \u0080 \U00000080
        # 0xff "\xff" "\xc3\xbf" \u00ff \U000000ff
       # 0x100 N/A "\xc4\x80" \u0100 \U00000100
        # 0x1000 N/A "\xc8\x80" \u1000 \U00001000
        # 0xffff N/A "\xef\xbf\xbf" \uffff \U0000ffff
        # 0x10000 N/A "\xf0\x90\x80\x80" N/A \U00010000
        # 0xfffff N/A "\xf3\xbf\xbf\xbf" N/A \U000fffff
        # 0x10000000 N/A "\xfc\x90\x80\x80\x80\x80" N/A \U10000000
        # 0x7fffffff N/A "\xfd\xbf\xbf\xbf\xbf\xbf" N/A \U7fffffff
        # 0x80000000 N/A N/A N/A N/A
        # 0xffffffff N/A N/A N/A N/A

        ###########################################################################
       ## ord family
        ###########################################################################
       # ord <Return Variable Name> <Char to convert> [Optional Format String]
        # ord.hex <Return Variable Name> <Char to convert>
        # ord.oct <Return Variable Name> <Char to convert>
        # ord.utf8 <Return Variable Name> <Char to convert> [Optional Format String]
        # ord.eascii <Return Variable Name> <Char to convert> [Optional Format String]
        # ord.echo <Char to convert> [Optional Format String]
        # ord.hex.echo <Char to convert>
        # ord.oct.echo <Char to convert>
        # ord.utf8.echo <Char to convert> [Optional Format String]
        # ord.eascii.echo <Char to convert> [Optional Format String]
        #
       # Description:
        # converts character using native encoding to its decimal value and stores
        # it in the Variable specified
        #
       # ord
        # ord.hex output in hex
        # ord.hex output in octal
        # ord.utf8 forces UTF8 decoding
        # ord.eascii forces eascii decoding
        # ord.echo prints to stdout
        function ord {
       printf -v "${1?Missing Dest Variable}" "${3:-%d}" "'${2?Missing Char}"
        }
        function ord.oct {
       ord "${@:1:2}" "0%c"
        }
        function ord.hex {
       ord "${@:1:2}" "0x%x"
        }
        function ord.utf8 {
                LC_CTYPE=en_US.UTF8 ord "${@}"
        }
        function ord.eascii {
       LC_CTYPE=C ord "${@}"
        }
        function ord.echo {
                printf "${2:-%d}" "'${1?Missing Char}"
        }
        function ord.oct.echo {
                ord.echo "${1}" "0%o"
        }
        function ord.hex.echo {
                ord.echo "${1}" "0x%x"
        }
        function ord.utf8.echo {
                LC_CTYPE=en_US.UTF8 ord.echo "${@}"
        }
        function ord.eascii.echo {
       LC_CTYPE=C ord.echo "${@}"
        }

        ###########################################################################
       ## chr family
        ###########################################################################
        # chr.utf8 <Return Variale Name> <Integer to convert>
        # chr.eascii <Return Variale Name> <Integer to convert>
        # chr <Return Variale Name> <Integer to convert>
        # chr.oct <Return Variale Name> <Octal number to convert>
        # chr.hex <Return Variale Name> <Hex number to convert>
        # chr.utf8.echo <Integer to convert>
        # chr.eascii.echo <Integer to convert>
        # chr.echo <Integer to convert>
        # chr.oct.echo <Octal number to convert>
        # chr.hex.echo <Hex number to convert>
        #
       # Description:
        # converts decimal value to character representation an stores
        # it in the Variable specified
        #
       # chr Tries to guess output format
        # chr.utf8 forces UTF8 encoding
        # chr.eascii forces eascii encoding
        # chr.echo prints to stdout
        #
        function chr.utf8 {
                local val
       [[ ${2?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

                if [[ ${2} -lt 0x100 && ${2} -ge 0x80 ]]; then
                        # some kinda weird bash? behavior
                        # treats \Uff as \xff so encode manually
       printf -v val "\\%o\%o" $(( (${2}>>6)|0xc0 )) $(( (${2}&0x3f)|0x80 ))
                else
                        # Note in embedded cases always do \U%08x \u04x
                        # here however no need to because of the EOS
                        printf -v val '\\U%x' "${2}"
                fi
       printf -v ${1?Missing Dest Variable} ${val}
        }
        function chr.eascii {
                local val
                # Make sure value less than 0x100
                # otherwise we end up with         # \xVVNNNNN         # where \xVV = char && NNNNN is a number string
                # so chr "0x44321" => "D321"
                [[ ${2?Missing Ordinal Value} -lt 0x100 ]] || return 1
                printf -v val '\\x%02x' "${2}"
       printf -v ${1?Missing Dest Variable} ${val}
        }
        function chr {
       if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                        chr.eascii "${@}"
                else
                        chr.utf8 "${@}"
                fi
       }
        function chr.dec {
                # strip leading 0s otherwise         # interpreted as Octal
       if shopt extglob &>/dev/null ;then         chr "${1}" "${2/#+(0)}"
                else
       shopt -s extglob
       chr "${1}" "${2/#+(0)}"
                        shopt -u extglob
                fi
       }
        function chr.oct {
       chr "${1}" "0${2}"
        }
        function chr.hex {
       chr "${1}" "0x${2}"
        }
        function chr.utf8.echo {
                local val         [[ ${1?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

                if [[ ${1} -lt 0x100 && ${1} -ge 0x80 ]]; then
                        # some kinda weird bash? behavior
                        # treats \Uff as \xff so encode manually
       printf -v val '\\%o\\%o' $(( (${1}>>6)|0xc0 )) $(( (${1}&0x3f)|0x80 ))
                else
                        # Note in embedded cases always do \\U%08x \u04x
                        # here however no need to because of the EOS
                        printf -v val '\\U%x' "${1}"
                fi
       printf "${val}"
        }
        function chr.eascii.echo {
                local val
                # Make sure value less than 0x100
                # otherwise we end up with         # \xVVNNNNN         # where \xVV = char && NNNNN is a number string
                # so chr "0x44321" => "D321"
                [[ ${1?Missing Ordinal Value} -lt 0x100 ]] || return 1
                printf -v val '\\x%x' "${1}"
                printf "${val}"
        }
        function chr.echo {
       if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                        chr.eascii.echo "${@}"
                else
                        chr.utf8.echo "${@}"
                fi
       }
        function chr.dec.echo {
                # strip leading 0s otherwise         # interpreted as Octal
       if shopt extglob &>/dev/null ;then                          chr.echo "${1/#+(0)}"
                else
       shopt -s extglob
                        chr.echo "${1/#+(0)}"
                        shopt -u extglob
                fi
       }
        function chr.oct.echo {
                chr.echo "0${1}"
        }
        function chr.hex.echo {
                chr.echo "0x${1}"
        }
        #
   # Simple Validation code
    #
     function test_echo_func {
        local Outcome
        local _result="$( "${1}" "${2}" )"
        if [ "${_result}" = "${3}" ]; then
          Outcome="Pass"
        else
          Outcome="Fail"
        fi
     printf "# %-20s %-6s => [ "%16q" = "%-16q"%-5s ] %s\n" "${1}" "${2}" "${_result}" "${3}" "(${3//[[:cntrl:]]/_})" "${Outcome}"
     }         function test_value_func {
        local Outcome
        local _result
     "${1}" _result "${2}"
        if [ "${_result}" = "${3}" ]; then
          Outcome="Pass"
        else
          Outcome="Fail"
        fi
     printf "# %-20s %-6s => [ "%16q" = "%-16q"%-5s ] %s\n" "${1}" "${2}" "${_result}" "${3}" "(${3//[[:cntrl:]]/_})" "${Outcome}"
      }        test_echo_func chr.echo "$(ord.echo A)"   "A"
    test_echo_func ord.echo "$(chr.echo 65)"  "65"
    test_echo_func chr.echo "$(ord.echo "ö")" "ö"
    test_value_func chr "$(ord.echo A)"   "A"
    test_value_func ord "$(chr.echo 65)"  "65"
    test_value_func chr "$(ord.echo "ö")" "ö"
# chr.echo 65 => [ A = A (A) ] Pass
# ord.echo A => [ 65 = 65 (65) ] Pass
# chr.echo 246 => [ $'\303\266' = $'\303\266' (ö) ] Pass
# chr 65 => [ A = A (A) ] Pass
# ord A => [ 65 = 65 (65) ] Pass
# chr 246 => [ $'\303\266' = $'\303\266' (ö) ] Pass
#


    test_echo_func chr.echo "65" A
    test_echo_func chr.echo "065" 5
    test_echo_func chr.dec.echo "065" A
    test_echo_func chr.oct.echo "65" 5
    test_echo_func chr.hex.echo "65" e
    test_value_func chr "65" A
    test_value_func chr "065" 5
    test_value_func chr.dec "065" A
    test_value_func chr.oct "65" 5
    test_value_func chr.hex "65" e
# chr.echo 65 => [ A = A (A) ] Pass
# chr.echo 065 => [ 5 = 5 (5) ] Pass
# chr.dec.echo 065 => [ A = A (A) ] Pass
# chr.oct.echo 65 => [ 5 = 5 (5) ] Pass
# chr.hex.echo 65 => [ e = e (e) ] Pass
# chr 65 => [ A = A (A) ] Pass
# chr 065 => [ 5 = 5 (5) ] Pass
# chr.dec 065 => [ A = A (A) ] Pass
# chr.oct 65 => [ 5 = 5 (5) ] Pass
# chr.hex 65 => [ e = e (e) ] Pass

    #test_value_func chr 0xff $'\xff'        test_value_func chr.eascii 0xff $'\xff'        test_value_func chr.utf8 0xff $'\uff' # Note this fails because bash encodes it wrong
   test_value_func chr.utf8 0xff $'\303\277'        test_value_func chr.utf8 0x100 $'\u100'        test_value_func chr.utf8 0x1000 $'\u1000'       test_value_func chr.utf8 0xffff $'\uffff'    # chr.eascii 0xff => [ $'\377' = $'\377' (�) ] Pass
# chr.utf8 0xff => [ $'\303\277' = $'\377' (�) ] Fail
# chr.utf8 0xff => [ $'\303\277' = $'\303\277' (ÿ) ] Pass
# chr.utf8 0x100 => [ $'\304\200' = $'\304\200' (Ā) ] Pass
# chr.utf8 0x1000 => [ $'\341\200\200' = $'\341\200\200' (က) ] Pass
# chr.utf8 0xffff => [ $'\357\277\277' = $'\357\277\277' (���) ] Pass		 {{{#!highlight bash numbers=disable
  ###############################################################
  #
 # Note about Ext Ascii and UTF-8 encoding
  #
 # for values 0x00 - 0x7f Identical
  # for values 0x80 - 0xff conflict between UTF-8 & ExtAscii
  # for values 0x100 - 0xffff Only UTF-8 UTF-16 UTF-32
  # for values 0x100 - 0x7FFFFFFF Only UTF-8 UTF-32
  #
 # value EAscii UTF-8 UTF-16 UTF-32
  # 0x20 "\x20" "\x20" \u0020 \U00000020
  # 0x20 "\x7f" "\x7f" \u007f \U0000007f
  # 0x80 "\x80" "\xc2\x80" \u0080 \U00000080
  # 0xff "\xff" "\xc3\xbf" \u00ff \U000000ff
  # 0x100 N/A "\xc4\x80" \u0100 \U00000100
  # 0x1000 N/A "\xc8\x80" \u1000 \U00001000
  # 0xffff N/A "\xef\xbf\xbf" \uffff \U0000ffff
  # 0x10000 N/A "\xf0\x90\x80\x80" N/A \U00010000
  # 0xfffff N/A "\xf3\xbf\xbf\xbf" N/A \U000fffff
  # 0x10000000 N/A "\xfc\x90\x80\x80\x80\x80" N/A \U10000000
  # 0x7fffffff N/A "\xfd\xbf\xbf\xbf\xbf\xbf" N/A \U7fffffff
  # 0x80000000 N/A N/A N/A N/A
  # 0xffffffff N/A N/A N/A N/A

  ###########################################################################
 ## ord family
  ###########################################################################
 # ord <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_hex <Return Variable Name> <Char to convert>
  # ord_oct <Return Variable Name> <Char to convert>
  # ord_utf8 <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_eascii <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_echo <Char to convert> [Optional Format String]
  # ord_hex_echo <Char to convert>
  # ord_oct_echo <Char to convert>
  # ord_utf8_echo <Char to convert> [Optional Format String]
  # ord_eascii_echo <Char to convert> [Optional Format String]
  #
 # Description:
  # converts character using native encoding to its decimal value and stores
  # it in the Variable specified
  #
 # ord
  # ord_hex output in hex
  # ord_hex output in octal
  # ord_utf8 forces UTF8 decoding
  # ord_eascii forces eascii decoding
  # ord_echo prints to stdout
  function ord {
          printf -v "${1?Missing Dest Variable}" "${3:-%d}" "'${2?Missing Char}"
  }
  function ord_oct {
          ord "${@:1:2}" "0%c"
  }
  function ord_hex {
          ord "${@:1:2}" "0x%x"
  }
  function ord_utf8 {
          LC_CTYPE=C.UTF-8 ord "${@}"
  }
  function ord_eascii {
          LC_CTYPE=C ord "${@}"
  }
  function ord_echo {
 printf "${2:-%d}" "'${1?Missing Char}"
  }
  function ord_oct_echo {
          ord_echo "${1}" "0%o"
  }
  function ord_hex_echo {
          ord_echo "${1}" "0x%x"
  }
  function ord_utf8_echo {
          LC_CTYPE=C.UTF-8 ord_echo "${@}"
  }
  function ord_eascii_echo {
          LC_CTYPE=C ord_echo "${@}"
  }

  ###########################################################################
 ## chr family
  ###########################################################################
  # chr_utf8 <Return Variale Name> <Integer to convert>
  # chr_eascii <Return Variale Name> <Integer to convert>
  # chr <Return Variale Name> <Integer to convert>
  # chr_oct <Return Variale Name> <Octal number to convert>
  # chr_hex <Return Variale Name> <Hex number to convert>
  # chr_utf8_echo <Integer to convert>
  # chr_eascii_echo <Integer to convert>
  # chr_echo <Integer to convert>
  # chr_oct_echo <Octal number to convert>
  # chr_hex_echo <Hex number to convert>
  #
 # Description:
  # converts decimal value to character representation an stores
  # it in the Variable specified
  #
 # chr Tries to guess output format
  # chr_utf8 forces UTF8 encoding
  # chr_eascii forces eascii encoding
  # chr_echo prints to stdout
  #
  function chr_utf8 {
          local val
          [[ ${2?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

          if [[ ${2} -lt 0x100 && ${2} -ge 0x80 ]]; then
                  # some kinda weird bash? behavior
                  # treats \Uff as \xff so encode manually
                  printf -v val "\\%03o\%03o" $(( (${2}>>6)|0xc0 )) $(( (${2}&0x3f)|0x80 ))
          else
                  printf -v val '\\U%08x' "${2}"
          fi
 printf -v ${1?Missing Dest Variable} ${val}
  }
  function chr_eascii {
          local val
          # Make sure value less than 0x100
          # otherwise we end up with
 # \xVVNNNNN
 # where \xVV = char && NNNNN is a number string
          # so chr "0x44321" => "D321"
          [[ ${2?Missing Ordinal Value} -lt 0x100 ]] || return 1
          printf -v val '\\x%02x' "${2}"
          printf -v ${1?Missing Dest Variable} ${val}
  }
  function chr {
          if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                  chr_eascii "${@}"
          else
                  chr_utf8 "${@}"
          fi
 }
  function chr_dec {
          # strip leading 0s otherwise
 # interpreted as Octal
          if shopt extglob &>/dev/null ;then
 chr "${1}" "${2/#+(0)}"
          else
 shopt -s extglob
                  chr "${1}" "${2/#+(0)}"
                  shopt -u extglob
          fi
 }
  function chr_oct {
          chr "${1}" "0${2}"
  }
  function chr_hex {
          chr "${1}" "0x${2}"
  }
  function chr_utf8_echo {
          local val
 [[ ${1?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

          if [[ ${1} -lt 0x100 && ${1} -ge 0x80 ]]; then
                  # some kinda weird bash? behavior
                  # treats \Uff as \xff so encode manually
                  printf -v val '\\%03o\\%03o' $(( (${1}>>6)|0xc0 )) $(( (${1}&0x3f)|0x80 ))
          else
                  printf -v val '\\U%08x' "${1}"
          fi
 printf "${val}"
  }
  function chr_eascii_echo {
          local val
          # Make sure value less than 0x100
          # otherwise we end up with
 # \xVVNNNNN
 # where \xVV = char && NNNNN is a number string
          # so chr "0x44321" => "D321"
          [[ ${1?Missing Ordinal Value} -lt 0x100 ]] || return 1
          printf -v val '\\x%x' "${1}"
          printf "${val}"
  }
  function chr_echo {
          if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                  chr_eascii_echo "${@}"
          else
                  chr_utf8_echo "${@}"
          fi
 }
  function chr_dec_echo {
          # strip leading 0s otherwise
 # interpreted as Octal
          if shopt extglob &>/dev/null ;then
                  chr_echo "${1/#+(0)}"
          else
 shopt -s extglob
                  chr_echo "${1/#+(0)}"
                  shopt -u extglob
          fi
 }
  function chr_oct_echo {
          chr_echo "0${1}"
  }
  function chr_hex_echo {
          chr_echo "0x${1}"
  }

  #
 # Simple Validation code
  #
 function test_echo_func {
    local Outcome _result
    _result="$( "${1}" "${2}" )"
    [ "${_result}" = "${3}" ] && Outcome="Pass" || Outcome="Fail"
    printf "# %-20s %-6s => " "${1}" "${2}" "${_result}" "${3}"
    printf "[ "%16q" = "%-16q"%-5s ] " "${_result}" "${3}" "(${3//[[:cntrl:]]/_})"
    printf "%s\n" "${Outcome}"


 }
 function test_value_func {
    local Outcome _result
 "${1}" _result "${2}"
    [ "${_result}" = "${3}" ] && Outcome="Pass" || Outcome="Fail"
    printf "# %-20s %-6s => " "${1}" "${2}" "${_result}" "${3}"
    printf "[ "%16q" = "%-16q"%-5s ] " "${_result}" "${3}" "(${3//[[:cntrl:]]/_})"
    printf "%s\n" "${Outcome}"
  }
  test_echo_func chr_echo "$(ord_echo "A")" "A"
  test_echo_func ord_echo "$(chr_echo "65")" "65"
  test_echo_func chr_echo "$(ord_echo "ö")" "ö"
  test_value_func chr  "$(ord_echo "A")" "A"
  test_value_func ord  "$(chr_echo "65")" "65"
  test_value_func chr  "$(ord_echo "ö")" "ö"
  # chr_echo 65 => [ A = A (A) ] Pass
  # ord_echo A => [ 65 = 65 (65) ] Pass
  # chr_echo 246 => [ $'\303\266' = $'\303\266' (ö) ] Pass
  # chr 65 => [ A = A (A) ] Pass
  # ord A => [ 65 = 65 (65) ] Pass
  # chr 246 => [ $'\303\266' = $'\303\266' (ö) ] Pass
  #


  test_echo_func chr_echo "65" A
  test_echo_func chr_echo "065" 5
  test_echo_func chr_dec_echo "065" A
  test_echo_func chr_oct_echo "65" 5
  test_echo_func chr_hex_echo "65" e
  test_value_func chr "65" A
  test_value_func chr "065" 5
  test_value_func chr_dec "065" A
  test_value_func chr_oct "65" 5
  test_value_func chr_hex "65" e
  # chr_echo 65 => [ A = A (A) ] Pass
  # chr_echo 065 => [ 5 = 5 (5) ] Pass
  # chr_dec_echo 065 => [ A = A (A) ] Pass
  # chr_oct_echo 65 => [ 5 = 5 (5) ] Pass
  # chr_hex_echo 65 => [ e = e (e) ] Pass
  # chr 65 => [ A = A (A) ] Pass
  # chr 065 => [ 5 = 5 (5) ] Pass
  # chr_dec 065 => [ A = A (A) ] Pass
  # chr_oct 65 => [ 5 = 5 (5) ] Pass
  # chr_hex 65 => [ e = e (e) ] Pass

  #test_value_func chr 0xff $'\xff'
 test_value_func chr_eascii 0xff $'\xff'
 test_value_func chr_utf8 0xff $'\uff' # Note this fails because bash encodes it incorrectly
 test_value_func chr_utf8 0xff $'\303\277'
 test_value_func chr_utf8 0x100 $'\u100'
 test_value_func chr_utf8 0x1000 $'\u1000'
 test_value_func chr_utf8 0xffff $'\uffff'
  # chr_eascii 0xff => [ $'\377' = $'\377' (�) ] Pass
  # chr_utf8 0xff => [ $'\303\277' = $'\377' (�) ] Fail
  # chr_utf8 0xff => [ $'\303\277' = $'\303\277' (ÿ) ] Pass
  # chr_utf8 0x100 => [ $'\304\200' = $'\304\200' (Ā) ] Pass
  # chr_utf8 0x1000 => [ $'\341\200\200' = $'\341\200\200' (က) ] Pass
  # chr_utf8 0xffff => [ $'\357\277\277' = $'\357\277\277' (���) ] Pass
  test_value_func ord_utf8 "A" 65
  test_value_func ord_utf8 "ä" 228
  test_value_func ord_utf8 $'\303\277' 255
  test_value_func ord_utf8 $'\u100' 256
Line 305: Line 302:
  printf "%q\n" "$(chr.utf8.echo 0x100)" # => $'\304\200'
  #
  # This can help a lot when it comes to diagnosing problems 
  # with read and or xterm program output 		   printf "%q\n" "$(chr_utf8_echo 0x100)" # => $'\304\200'
  #
  # This can help a lot when it comes to diagnosing problems
  # with read and or xterm program output
Line 310: Line 307:
  # i.e.    # i.e.
Line 326: Line 323:
  EAsciiLookup=$'\001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023\024\025\026\027\030\031\032\E\034\035\036\037 !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
  function ord.eascii2 {		   EAsciiLookup=$'\001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023'
  EAsciiLookup+=$'\024\025\026\027\030\031\032\E\034\035\036\037 !"#$%&\'()*+,-'
  EAsciiLookup+=$'./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghi'
  EAsciiLookup+=$'jklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210'
  EAsciiLookup+=$'\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227'
  EAsciiLookup+=$'\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246'
  EAsciiLookup+=$'\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265'
  EAsciiLookup+=$'\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304'
  EAsciiLookup+=$'\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323'
  EAsciiLookup+=$'\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342'
  EAsciiLookup+=$'\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361'
  EAsciiLookup+=$'\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
  function ord_eascii2 {
Line 338: Line 346:
    [_$'\001']="0x01" [_$'\002']="0x02" [_$'\003']="0x03" [_$'\004']="0x04" 
    [_$'\005']="0x05" [_$'\006']="0x06" [_$'\a']="0x07" [_$'\b']="0x08"   
    [_$'\t']="0x09" [_'']="0x0a" [_$'\v']="0x0b" [_$'\f']="0x0c"   
    [_$'\r']="0x0d" [_$'\016']="0x0e" [_$'\017']="0x0f" [_$'\020']="0x10"      [_$'\021']="0x11" [_$'\022']="0x12" [_$'\023']="0x13" [_$'\024']="0x14"
    [_$'\025']="0x15" [_$'\026']="0x16" [_$'\027']="0x17" [_$'\030']="0x18" 
    [_$'\031']="0x19" [_$'\032']="0x1a" [_$'\E']="0x1b" [_$'\034']="0x1c" 
    [_$'\035']="0x1d" [_$'\036']="0x1e" [_$'\037']="0x1f" [_\ ]="0x20"      
    [_\!]="0x21" [_\"]="0x22" [_\#]="0x23" [_\$]="0x24"      
    [_%]="0x25" [_\&]="0x26" [_\']="0x27" [_\(]="0x28"      
    [_\)]="0x29" [_\*]="0x2a" [_+]="0x2b" [_\,]="0x2c"      
    [_-]="0x2d" [_.]="0x2e" [_/]="0x2f" [_0]="0x30"            [_1]="0x31" [_2]="0x32" [_3]="0x33" [_4]="0x34"
    [_5]="0x35" [_6]="0x36" [_7]="0x37" [_8]="0x38"       
    [_9]="0x39" [_:]="0x3a" [_\;]="0x3b" [_\<]="0x3c"      
    [_=]="0x3d" [_\>]="0x3e" [_\?]="0x3f" [_@]="0x40"       
    [_A]="0x41" [_B]="0x42" [_C]="0x43" [_D]="0x44"       
    [_E]="0x45" [_F]="0x46" [_G]="0x47" [_H]="0x48"       
    [_I]="0x49" [_J]="0x4a" [_K]="0x4b" [_L]="0x4c"       
    [_M]="0x4d" [_N]="0x4e" [_O]="0x4f" [_P]="0x50"       
    [_Q]="0x51" [_R]="0x52" [_S]="0x53" [_T]="0x54"       
    [_U]="0x55" [_V]="0x56" [_W]="0x57" [_X]="0x58"       
    [_Y]="0x59" [_Z]="0x5a" [_\[]="0x5b" #[_\\]="0x5c"      
    #[_\]]="0x5d"      
                      [_\^]="0x5e" [__]="0x5f" [_\`]="0x60"      
    [_a]="0x61" [_b]="0x62" [_c]="0x63" [_d]="0x64"       
    [_e]="0x65" [_f]="0x66" [_g]="0x67" [_h]="0x68"       
    [_i]="0x69" [_j]="0x6a" [_k]="0x6b" [_l]="0x6c"       
    [_m]="0x6d" [_n]="0x6e" [_o]="0x6f" [_p]="0x70"       
    [_q]="0x71" [_r]="0x72" [_s]="0x73" [_t]="0x74"       
    [_u]="0x75" [_v]="0x76" [_w]="0x77" [_x]="0x78"       
    [_y]="0x79" [_z]="0x7a" [_\{]="0x7b" [_\|]="0x7c"      
    [_\}]="0x7d" [_~]="0x7e" [_$'\177']="0x7f" [_$'\200']="0x80" 
    [_$'\201']="0x81" [_$'\202']="0x82" [_$'\203']="0x83" [_$'\204']="0x84" 
    [_$'\205']="0x85" [_$'\206']="0x86" [_$'\207']="0x87" [_$'\210']="0x88" 
    [_$'\211']="0x89" [_$'\212']="0x8a" [_$'\213']="0x8b" [_$'\214']="0x8c" 
    [_$'\215']="0x8d" [_$'\216']="0x8e" [_$'\217']="0x8f" [_$'\220']="0x90" 
    [_$'\221']="0x91" [_$'\222']="0x92" [_$'\223']="0x93" [_$'\224']="0x94" 
    [_$'\225']="0x95" [_$'\226']="0x96" [_$'\227']="0x97" [_$'\230']="0x98" 
    [_$'\231']="0x99" [_$'\232']="0x9a" [_$'\233']="0x9b" [_$'\234']="0x9c" 
    [_$'\235']="0x9d" [_$'\236']="0x9e" [_$'\237']="0x9f" [_$'\240']="0xa0" 
    [_$'\241']="0xa1" [_$'\242']="0xa2" [_$'\243']="0xa3" [_$'\244']="0xa4" 
    [_$'\245']="0xa5" [_$'\246']="0xa6" [_$'\247']="0xa7" [_$'\250']="0xa8" 
    [_$'\251']="0xa9" [_$'\252']="0xaa" [_$'\253']="0xab" [_$'\254']="0xac" 
    [_$'\255']="0xad" [_$'\256']="0xae" [_$'\257']="0xaf" [_$'\260']="0xb0" 
    [_$'\261']="0xb1" [_$'\262']="0xb2" [_$'\263']="0xb3" [_$'\264']="0xb4" 
    [_$'\265']="0xb5" [_$'\266']="0xb6" [_$'\267']="0xb7" [_$'\270']="0xb8" 
    [_$'\271']="0xb9" [_$'\272']="0xba" [_$'\273']="0xbb" [_$'\274']="0xbc" 
    [_$'\275']="0xbd" [_$'\276']="0xbe" [_$'\277']="0xbf" [_$'\300']="0xc0" 
    [_$'\301']="0xc1" [_$'\302']="0xc2" [_$'\303']="0xc3" [_$'\304']="0xc4" 
    [_$'\305']="0xc5" [_$'\306']="0xc6" [_$'\307']="0xc7" [_$'\310']="0xc8" 
    [_$'\311']="0xc9" [_$'\312']="0xca" [_$'\313']="0xcb" [_$'\314']="0xcc" 
    [_$'\315']="0xcd" [_$'\316']="0xce" [_$'\317']="0xcf" [_$'\320']="0xd0" 
    [_$'\321']="0xd1" [_$'\322']="0xd2" [_$'\323']="0xd3" [_$'\324']="0xd4" 
    [_$'\325']="0xd5" [_$'\326']="0xd6" [_$'\327']="0xd7" [_$'\330']="0xd8" 
    [_$'\331']="0xd9" [_$'\332']="0xda" [_$'\333']="0xdb" [_$'\334']="0xdc" 
    [_$'\335']="0xdd" [_$'\336']="0xde" [_$'\337']="0xdf" [_$'\340']="0xe0" 
    [_$'\341']="0xe1" [_$'\342']="0xe2" [_$'\343']="0xe3" [_$'\344']="0xe4" 
    [_$'\345']="0xe5" [_$'\346']="0xe6" [_$'\347']="0xe7" [_$'\350']="0xe8" 
    [_$'\351']="0xe9" [_$'\352']="0xea" [_$'\353']="0xeb" [_$'\354']="0xec" 
    [_$'\355']="0xed" [_$'\356']="0xee" [_$'\357']="0xef" [_$'\360']="0xf0" 
    [_$'\361']="0xf1" [_$'\362']="0xf2" [_$'\363']="0xf3" [_$'\364']="0xf4" 
    [_$'\365']="0xf5" [_$'\366']="0xf6" [_$'\367']="0xf7" [_$'\370']="0xf8" 
    [_$'\371']="0xf9" [_$'\372']="0xfa" [_$'\373']="0xfb" [_$'\374']="0xfc" 
    [_$'\375']="0xfd" [_$'\376']="0xfe" [_$'\377']="0xff" 		     [_$'\001']="0x01" [_$'\002']="0x02" [_$'\003']="0x03" [_$'\004']="0x04"
    [_$'\005']="0x05" [_$'\006']="0x06" [_$'\a']="0x07" [_$'\b']="0x08"
    [_$'\t']="0x09" [_'']="0x0a" [_$'\v']="0x0b" [_$'\f']="0x0c"
    [_$'\r']="0x0d" [_$'\016']="0x0e" [_$'\017']="0x0f" [_$'\020']="0x10"
    [_$'\021']="0x11" [_$'\022']="0x12" [_$'\023']="0x13" [_$'\024']="0x14"
    [_$'\025']="0x15" [_$'\026']="0x16" [_$'\027']="0x17" [_$'\030']="0x18"
    [_$'\031']="0x19" [_$'\032']="0x1a" [_$'\E']="0x1b" [_$'\034']="0x1c"
    [_$'\035']="0x1d" [_$'\036']="0x1e" [_$'\037']="0x1f" [_\ ]="0x20"
    [_\!]="0x21" [_\"]="0x22" [_\#]="0x23" [_\$]="0x24"
    [_%]="0x25" [_\&]="0x26" [_\']="0x27" [_\(]="0x28"
    [_\)]="0x29" [_\*]="0x2a" [_+]="0x2b" [_\,]="0x2c"
    [_-]="0x2d" [_.]="0x2e" [_/]="0x2f" [_0]="0x30"
    [_1]="0x31" [_2]="0x32" [_3]="0x33" [_4]="0x34"
    [_5]="0x35" [_6]="0x36" [_7]="0x37" [_8]="0x38"
    [_9]="0x39" [_:]="0x3a" [_\;]="0x3b" [_\<]="0x3c"
    [_=]="0x3d" [_\>]="0x3e" [_\?]="0x3f" [_@]="0x40"
    [_A]="0x41" [_B]="0x42" [_C]="0x43" [_D]="0x44"
    [_E]="0x45" [_F]="0x46" [_G]="0x47" [_H]="0x48"
    [_I]="0x49" [_J]="0x4a" [_K]="0x4b" [_L]="0x4c"
    [_M]="0x4d" [_N]="0x4e" [_O]="0x4f" [_P]="0x50"
    [_Q]="0x51" [_R]="0x52" [_S]="0x53" [_T]="0x54"
    [_U]="0x55" [_V]="0x56" [_W]="0x57" [_X]="0x58"
    [_Y]="0x59" [_Z]="0x5a" [_\[]="0x5b" #[_\\]="0x5c"
    #[_\]]="0x5d"
                      [_\^]="0x5e" [__]="0x5f" [_\`]="0x60"
    [_a]="0x61" [_b]="0x62" [_c]="0x63" [_d]="0x64"
    [_e]="0x65" [_f]="0x66" [_g]="0x67" [_h]="0x68"
    [_i]="0x69" [_j]="0x6a" [_k]="0x6b" [_l]="0x6c"
    [_m]="0x6d" [_n]="0x6e" [_o]="0x6f" [_p]="0x70"
    [_q]="0x71" [_r]="0x72" [_s]="0x73" [_t]="0x74"
    [_u]="0x75" [_v]="0x76" [_w]="0x77" [_x]="0x78"
    [_y]="0x79" [_z]="0x7a" [_\{]="0x7b" [_\|]="0x7c"
    [_\}]="0x7d" [_~]="0x7e" [_$'\177']="0x7f" [_$'\200']="0x80"
    [_$'\201']="0x81" [_$'\202']="0x82" [_$'\203']="0x83" [_$'\204']="0x84"
    [_$'\205']="0x85" [_$'\206']="0x86" [_$'\207']="0x87" [_$'\210']="0x88"
    [_$'\211']="0x89" [_$'\212']="0x8a" [_$'\213']="0x8b" [_$'\214']="0x8c"
    [_$'\215']="0x8d" [_$'\216']="0x8e" [_$'\217']="0x8f" [_$'\220']="0x90"
    [_$'\221']="0x91" [_$'\222']="0x92" [_$'\223']="0x93" [_$'\224']="0x94"
    [_$'\225']="0x95" [_$'\226']="0x96" [_$'\227']="0x97" [_$'\230']="0x98"
    [_$'\231']="0x99" [_$'\232']="0x9a" [_$'\233']="0x9b" [_$'\234']="0x9c"
    [_$'\235']="0x9d" [_$'\236']="0x9e" [_$'\237']="0x9f" [_$'\240']="0xa0"
    [_$'\241']="0xa1" [_$'\242']="0xa2" [_$'\243']="0xa3" [_$'\244']="0xa4"
    [_$'\245']="0xa5" [_$'\246']="0xa6" [_$'\247']="0xa7" [_$'\250']="0xa8"
    [_$'\251']="0xa9" [_$'\252']="0xaa" [_$'\253']="0xab" [_$'\254']="0xac"
    [_$'\255']="0xad" [_$'\256']="0xae" [_$'\257']="0xaf" [_$'\260']="0xb0"
    [_$'\261']="0xb1" [_$'\262']="0xb2" [_$'\263']="0xb3" [_$'\264']="0xb4"
    [_$'\265']="0xb5" [_$'\266']="0xb6" [_$'\267']="0xb7" [_$'\270']="0xb8"
    [_$'\271']="0xb9" [_$'\272']="0xba" [_$'\273']="0xbb" [_$'\274']="0xbc"
    [_$'\275']="0xbd" [_$'\276']="0xbe" [_$'\277']="0xbf" [_$'\300']="0xc0"
    [_$'\301']="0xc1" [_$'\302']="0xc2" [_$'\303']="0xc3" [_$'\304']="0xc4"
    [_$'\305']="0xc5" [_$'\306']="0xc6" [_$'\307']="0xc7" [_$'\310']="0xc8"
    [_$'\311']="0xc9" [_$'\312']="0xca" [_$'\313']="0xcb" [_$'\314']="0xcc"
    [_$'\315']="0xcd" [_$'\316']="0xce" [_$'\317']="0xcf" [_$'\320']="0xd0"
    [_$'\321']="0xd1" [_$'\322']="0xd2" [_$'\323']="0xd3" [_$'\324']="0xd4"
    [_$'\325']="0xd5" [_$'\326']="0xd6" [_$'\327']="0xd7" [_$'\330']="0xd8"
    [_$'\331']="0xd9" [_$'\332']="0xda" [_$'\333']="0xdb" [_$'\334']="0xdc"
    [_$'\335']="0xdd" [_$'\336']="0xde" [_$'\337']="0xdf" [_$'\340']="0xe0"
    [_$'\341']="0xe1" [_$'\342']="0xe2" [_$'\343']="0xe3" [_$'\344']="0xe4"
    [_$'\345']="0xe5" [_$'\346']="0xe6" [_$'\347']="0xe7" [_$'\350']="0xe8"
    [_$'\351']="0xe9" [_$'\352']="0xea" [_$'\353']="0xeb" [_$'\354']="0xec"
    [_$'\355']="0xed" [_$'\356']="0xee" [_$'\357']="0xef" [_$'\360']="0xf0"
    [_$'\361']="0xf1" [_$'\362']="0xf2" [_$'\363']="0xf3" [_$'\364']="0xf4"
    [_$'\365']="0xf5" [_$'\366']="0xf6" [_$'\367']="0xf7" [_$'\370']="0xf8"
    [_$'\371']="0xf9" [_$'\372']="0xfa" [_$'\373']="0xfb" [_$'\374']="0xfc"
    [_$'\375']="0xfd" [_$'\376']="0xfe" [_$'\377']="0xff"
Line 404: Line 412:
  function ord.eascii3 {   function ord_eascii3 {
Line 407: Line 415:
                case "${2:0:1}" in                  case "${2:0:1}" in
Line 415: Line 423:
  time for (( i=0 ; i <1000; i++ )); do ord TmpVar 'a'; done      time for (( i=0 ; i <1000; i++ )); do ord TmpVar 'a'; done
Line 420: Line 428:
  time for (( i=0 ; i <1000; i++ )); do ord.eascii TmpVar 'a'; done      time for (( i=0 ; i <1000; i++ )); do ord_eascii TmpVar 'a'; done
Line 425: Line 433:
  time for (( i=0 ; i <1000; i++ )); do ord.eascii2 TmpVar 'a'; done      time for (( i=0 ; i <1000; i++ )); do ord_utf8 TmpVar 'a'; done
  # real 0m0.225s
  # user 0m0.180s
  # sys 0m0.000s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii2 TmpVar 'a'; done
Line 430: Line 443:
  time for (( i=0 ; i <1000; i++ )); do ord.eascii3 TmpVar 'a'; done         time for (( i=0 ; i <1000; i++ )); do ord_eascii3 TmpVar 'a'; done
Line 434: Line 447:

  time for (( i=0 ; i <1000; i++ )); do ord_echo 'a' >/dev/null ; done
  # real 0m0.065s
  # user 0m0.044s
  # sys 0m0.016s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii_echo 'a' >/dev/null ; done
  # real 0m0.089s
  # user 0m0.068s
  # sys 0m0.008s

  time for (( i=0 ; i <1000; i++ )); do ord_utf8_echo 'a' >/dev/null ; done
  # real 0m0.226s
  # user 0m0.172s
  # sys 0m0.012s
Line 448: Line 476:
  
# Another version doing the octal conversion with arithmetic 
# Another version doing the octal conversion with arithmetic

How do I convert an ASCII character to its decimal (or hexadecimal) value and back?

If you have a known octal or hexadecimal value (at script-writing time), you can just use printf: 

   # POSIX
   printf '\x27\047\n'

This prints two literal ' characters (27 is the hexadecimal ASCII value of the character, and 47 is the octal value) and a newline. 

   ExpandedString=$'\x27\047\u0027\U00000027\n'
   echo -n "$ExpandedString"

Another approach $'...' strings are escaped before evaluation and can be embedded directly in code.

If you need to convert characters (or numeric ASCII values) that are not known in advance (i.e., in variables), you can use something a little more complicated:

  • The following example was submitted quite recently and needs to be cleaned up and validated. In particular, the function names with periods in them are abusing an undocumented, possibly unintended bash parsing glitch. 

  ###############################################################
  #
  #       Note about Ext Ascii and UTF-8 encoding
  #
  # for values 0x00   - 0x7f        Identical
  # for values 0x80   - 0xff        conflict between UTF-8 & ExtAscii
  # for values 0x100  - 0xffff      Only UTF-8 UTF-16 UTF-32
  # for values 0x100  - 0x7FFFFFFF  Only UTF-8 UTF-32
  #
  # value         EAscii   UTF-8                          UTF-16  UTF-32
  # 0x20          "\x20"  "\x20"                          \u0020  \U00000020
  # 0x20          "\x7f"  "\x7f"                          \u007f  \U0000007f
  # 0x80          "\x80"  "\xc2\x80"                      \u0080  \U00000080
  # 0xff          "\xff"  "\xc3\xbf"                      \u00ff  \U000000ff
  # 0x100         N/A     "\xc4\x80"                      \u0100  \U00000100
  # 0x1000        N/A     "\xc8\x80"                      \u1000  \U00001000
  # 0xffff        N/A     "\xef\xbf\xbf"                  \uffff  \U0000ffff
  # 0x10000       N/A     "\xf0\x90\x80\x80"              N/A     \U00010000
  # 0xfffff       N/A     "\xf3\xbf\xbf\xbf"              N/A     \U000fffff
  # 0x10000000    N/A     "\xfc\x90\x80\x80\x80\x80"      N/A     \U10000000
  # 0x7fffffff    N/A     "\xfd\xbf\xbf\xbf\xbf\xbf"      N/A     \U7fffffff
  # 0x80000000    N/A     N/A                             N/A     N/A
  # 0xffffffff    N/A     N/A                             N/A     N/A

  ###########################################################################
  ## ord family
  ###########################################################################
  # ord        <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_hex    <Return Variable Name> <Char to convert>
  # ord_oct    <Return Variable Name> <Char to convert>
  # ord_utf8   <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_eascii <Return Variable Name> <Char to convert> [Optional Format String]
  # ord_echo                      <Char to convert> [Optional Format String]
  # ord_hex_echo                  <Char to convert>
  # ord_oct_echo                  <Char to convert>
  # ord_utf8_echo                 <Char to convert> [Optional Format String]
  # ord_eascii_echo               <Char to convert> [Optional Format String]
  #
  # Description:
  # converts character using native encoding to its decimal value and stores
  # it in the Variable specified
  #
  #       ord
  #       ord_hex         output in hex
  #       ord_hex         output in octal
  #       ord_utf8        forces UTF8 decoding
  #       ord_eascii      forces eascii decoding
  #       ord_echo        prints to stdout
  function ord {
          printf -v "${1?Missing Dest Variable}" "${3:-%d}" "'${2?Missing Char}"
  }
  function ord_oct {
          ord "${@:1:2}" "0%c"
  }
  function ord_hex {
          ord "${@:1:2}" "0x%x"
  }
  function ord_utf8 {
          LC_CTYPE=C.UTF-8 ord "${@}"
  }
  function ord_eascii {
          LC_CTYPE=C ord "${@}"
  }
  function ord_echo {
          printf "${2:-%d}" "'${1?Missing Char}"
  }
  function ord_oct_echo {
          ord_echo "${1}" "0%o"
  }
  function ord_hex_echo {
          ord_echo "${1}" "0x%x"
  }
  function ord_utf8_echo {
          LC_CTYPE=C.UTF-8 ord_echo "${@}"
  }
  function ord_eascii_echo {
          LC_CTYPE=C ord_echo "${@}"
  }

  ###########################################################################
  ## chr family
  ###########################################################################
  # chr_utf8   <Return Variale Name> <Integer to convert>
  # chr_eascii <Return Variale Name> <Integer to convert>
  # chr        <Return Variale Name> <Integer to convert>
  # chr_oct    <Return Variale Name> <Octal number to convert>
  # chr_hex    <Return Variale Name> <Hex number to convert>
  # chr_utf8_echo                  <Integer to convert>
  # chr_eascii_echo                <Integer to convert>
  # chr_echo                       <Integer to convert>
  # chr_oct_echo                   <Octal number to convert>
  # chr_hex_echo                   <Hex number to convert>
  #
  # Description:
  # converts decimal value to character representation an stores
  # it in the Variable specified
  #
  #       chr                     Tries to guess output format
  #       chr_utf8                forces UTF8 encoding
  #       chr_eascii              forces eascii encoding
  #       chr_echo                prints to stdout
  #
  function chr_utf8 {
          local val
          [[ ${2?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

          if [[ ${2} -lt 0x100 && ${2} -ge 0x80 ]]; then
                  # some kinda weird bash? behavior
                  # treats \Uff as \xff so encode manually
                  printf -v val "\\%03o\%03o" $(( (${2}>>6)|0xc0 )) $(( (${2}&0x3f)|0x80 ))
          else
                  printf -v val '\\U%08x' "${2}"
          fi
          printf -v ${1?Missing Dest Variable} ${val}
  }
  function chr_eascii {
          local val
          # Make sure value less than 0x100
          # otherwise we end up with
          # \xVVNNNNN
          # where \xVV = char && NNNNN is a number string
          # so chr "0x44321" => "D321"
          [[ ${2?Missing Ordinal Value} -lt 0x100 ]] || return 1
          printf -v val '\\x%02x' "${2}"
          printf -v ${1?Missing Dest Variable} ${val}
  }
  function chr {
          if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                  chr_eascii "${@}"
          else
                  chr_utf8 "${@}"
          fi
  }
  function chr_dec {
          # strip leading 0s otherwise
          # interpreted as Octal
          if shopt extglob &>/dev/null ;then
                  chr "${1}" "${2/#+(0)}"
          else
                  shopt -s extglob
                  chr "${1}" "${2/#+(0)}"
                  shopt -u extglob
          fi
  }
  function chr_oct {
          chr "${1}" "0${2}"
  }
  function chr_hex {
          chr "${1}" "0x${2}"
  }
  function chr_utf8_echo {
          local val
          [[ ${1?Missing Ordinal Value} -lt 0x80000000 ]] || return 1

          if [[ ${1} -lt 0x100 && ${1} -ge 0x80 ]]; then
                  # some kinda weird bash? behavior
                  # treats \Uff as \xff so encode manually
                  printf -v val '\\%03o\\%03o' $(( (${1}>>6)|0xc0 )) $(( (${1}&0x3f)|0x80 ))
          else
                  printf -v val '\\U%08x' "${1}"
          fi
          printf "${val}"
  }
  function chr_eascii_echo {
          local val
          # Make sure value less than 0x100
          # otherwise we end up with
          # \xVVNNNNN
          # where \xVV = char && NNNNN is a number string
          # so chr "0x44321" => "D321"
          [[ ${1?Missing Ordinal Value} -lt 0x100 ]] || return 1
          printf -v val '\\x%x' "${1}"
          printf "${val}"
  }
  function chr_echo {
          if [ "${LC_CTYPE:-${LC_ALL:-}}" = "C" ]; then
                  chr_eascii_echo "${@}"
          else
                  chr_utf8_echo "${@}"
          fi
  }
  function chr_dec_echo {
          # strip leading 0s otherwise
          # interpreted as Octal
          if shopt extglob &>/dev/null ;then
                  chr_echo "${1/#+(0)}"
          else
                  shopt -s extglob
                  chr_echo "${1/#+(0)}"
                  shopt -u extglob
          fi
  }
  function chr_oct_echo {
          chr_echo "0${1}"
  }
  function chr_hex_echo {
          chr_echo "0x${1}"
  }

  #
  # Simple Validation code
  #
  function test_echo_func {
    local Outcome _result
    _result="$( "${1}" "${2}" )"
    [ "${_result}" = "${3}" ] && Outcome="Pass" || Outcome="Fail"
    printf "# %-20s %-6s => "           "${1}" "${2}" "${_result}" "${3}"
    printf "[ "%16q" = "%-16q"%-5s ] "  "${_result}" "${3}" "(${3//[[:cntrl:]]/_})"
    printf "%s\n"                       "${Outcome}"


  }
  function test_value_func {
    local Outcome _result
    "${1}" _result "${2}"
    [ "${_result}" = "${3}" ] && Outcome="Pass" || Outcome="Fail"
    printf "# %-20s %-6s => "           "${1}" "${2}" "${_result}" "${3}"
    printf "[ "%16q" = "%-16q"%-5s ] "  "${_result}" "${3}" "(${3//[[:cntrl:]]/_})"
    printf "%s\n"                       "${Outcome}"
  }
  test_echo_func  chr_echo "$(ord_echo  "A")"  "A"
  test_echo_func  ord_echo "$(chr_echo "65")"  "65"
  test_echo_func  chr_echo "$(ord_echo  "ö")"  "ö"
  test_value_func chr      "$(ord_echo  "A")"  "A"
  test_value_func ord      "$(chr_echo "65")"  "65"
  test_value_func chr      "$(ord_echo  "ö")"  "ö"
  # chr_echo             65     => [                A = A               (A)   ] Pass
  # ord_echo             A      => [               65 = 65              (65)  ] Pass
  # chr_echo             246    => [      $'\303\266' = $'\303\266'     (ö)  ] Pass
  # chr                  65     => [                A = A               (A)   ] Pass
  # ord                  A      => [               65 = 65              (65)  ] Pass
  # chr                  246    => [      $'\303\266' = $'\303\266'     (ö)  ] Pass
  #


  test_echo_func  chr_echo     "65"     A
  test_echo_func  chr_echo     "065"    5
  test_echo_func  chr_dec_echo "065"    A
  test_echo_func  chr_oct_echo "65"     5
  test_echo_func  chr_hex_echo "65"     e
  test_value_func chr          "65"     A
  test_value_func chr          "065"    5
  test_value_func chr_dec      "065"    A
  test_value_func chr_oct      "65"     5
  test_value_func chr_hex      "65"     e
  # chr_echo             65     => [                A = A               (A)   ] Pass
  # chr_echo             065    => [                5 = 5               (5)   ] Pass
  # chr_dec_echo         065    => [                A = A               (A)   ] Pass
  # chr_oct_echo         65     => [                5 = 5               (5)   ] Pass
  # chr_hex_echo         65     => [                e = e               (e)   ] Pass
  # chr                  65     => [                A = A               (A)   ] Pass
  # chr                  065    => [                5 = 5               (5)   ] Pass
  # chr_dec              065    => [                A = A               (A)   ] Pass
  # chr_oct              65     => [                5 = 5               (5)   ] Pass
  # chr_hex              65     => [                e = e               (e)   ] Pass

  #test_value_func chr          0xff   $'\xff'
  test_value_func chr_eascii   0xff   $'\xff'
  test_value_func chr_utf8     0xff   $'\uff'      # Note this fails because bash encodes it incorrectly
  test_value_func chr_utf8     0xff   $'\303\277'
  test_value_func chr_utf8     0x100  $'\u100'
  test_value_func chr_utf8     0x1000 $'\u1000'
  test_value_func chr_utf8     0xffff $'\uffff'
  # chr_eascii           0xff   => [          $'\377' = $'\377'         (�)   ] Pass
  # chr_utf8             0xff   => [      $'\303\277' = $'\377'         (�)   ] Fail
  # chr_utf8             0xff   => [      $'\303\277' = $'\303\277'     (ÿ)  ] Pass
  # chr_utf8             0x100  => [      $'\304\200' = $'\304\200'     (Ā)  ] Pass
  # chr_utf8             0x1000 => [  $'\341\200\200' = $'\341\200\200' (က) ] Pass
  # chr_utf8             0xffff => [  $'\357\277\277' = $'\357\277\277' (���) ] Pass
  test_value_func ord_utf8     "A"           65
  test_value_func ord_utf8     "ä"          228
  test_value_func ord_utf8     $'\303\277'  255
  test_value_func ord_utf8     $'\u100'     256



  #########################################################
  # to help debug problems try this
  #########################################################
  printf "%q\n" $'\xff'                  # => $'\377'
  printf "%q\n" $'\uffff'                # => $'\357\277\277'
  printf "%q\n" "$(chr_utf8_echo 0x100)" # => $'\304\200'
  #
  # This can help a lot when it comes to diagnosing problems
  # with read and or xterm program output
  # I use it a lot in error case to create a human readable error message
  # i.e.
  echo "Enter type to test, Enter to continue"
  while read -srN1 ; do
    ord asciiValue "${REPLY}"
    case "${asciiValue}" in
      10) echo "Goodbye" ; break ;;
      20|21|22) echo "Yay expected input" ;;
      *) printf ':( Unexpected Input 0x%02x %q "%s"\n' "${asciiValue}" "${REPLY}" "${REPLY//[[:cntrl:]]}" ;;
    esac
  done

  #########################################################
  # More exotic approach 1
  #########################################################
  # I used to use this before I figured out the LC_CTYPE=C approach
  # printf "EAsciiLookup=%q" "$(for (( x=0x0; x<0x100 ; x++)); do printf '%b' $(printf '\\x%02x' "$x"); done)"
  EAsciiLookup=$'\001\002\003\004\005\006\a\b\t\n\v\f\r\016\017\020\021\022\023'
  EAsciiLookup+=$'\024\025\026\027\030\031\032\E\034\035\036\037 !"#$%&\'()*+,-'
  EAsciiLookup+=$'./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghi'
  EAsciiLookup+=$'jklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210'
  EAsciiLookup+=$'\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227'
  EAsciiLookup+=$'\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246'
  EAsciiLookup+=$'\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265'
  EAsciiLookup+=$'\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304'
  EAsciiLookup+=$'\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323'
  EAsciiLookup+=$'\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342'
  EAsciiLookup+=$'\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361'
  EAsciiLookup+=$'\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
  function ord_eascii2 {
    local idx="${EAsciiLookup%%${2:0:1}*}"
    eval ${1}'=$(( ${#idx} +1 ))'
  }

  #########################################################
  # More exotic approach 2
  #########################################################
  #printf "EAsciiLookup2=(\n    %s\n)" "$(for (( x=0x1; x<0x100 ; x++)); do printf '%-18s'  "$(printf '[_%q]="0x%02x"' "$(printf "%b" "$(printf '\\x%02x' "$x")")" $x )" ; [ "$(($x%6))" != "0" ] || echo -en "\n    " ; done)"
  typeset -A EAsciiLookup2
  EAsciiLookup2=(
    [_$'\001']="0x01" [_$'\002']="0x02" [_$'\003']="0x03" [_$'\004']="0x04"
    [_$'\005']="0x05" [_$'\006']="0x06" [_$'\a']="0x07"   [_$'\b']="0x08"
    [_$'\t']="0x09"   [_'']="0x0a"      [_$'\v']="0x0b"   [_$'\f']="0x0c"
    [_$'\r']="0x0d"   [_$'\016']="0x0e" [_$'\017']="0x0f" [_$'\020']="0x10"
    [_$'\021']="0x11" [_$'\022']="0x12" [_$'\023']="0x13" [_$'\024']="0x14"
    [_$'\025']="0x15" [_$'\026']="0x16" [_$'\027']="0x17" [_$'\030']="0x18"
    [_$'\031']="0x19" [_$'\032']="0x1a" [_$'\E']="0x1b"   [_$'\034']="0x1c"
    [_$'\035']="0x1d" [_$'\036']="0x1e" [_$'\037']="0x1f" [_\ ]="0x20"
    [_\!]="0x21"      [_\"]="0x22"      [_\#]="0x23"      [_\$]="0x24"
    [_%]="0x25"       [_\&]="0x26"      [_\']="0x27"      [_\(]="0x28"
    [_\)]="0x29"      [_\*]="0x2a"      [_+]="0x2b"       [_\,]="0x2c"
    [_-]="0x2d"       [_.]="0x2e"       [_/]="0x2f"       [_0]="0x30"
    [_1]="0x31"       [_2]="0x32"       [_3]="0x33"       [_4]="0x34"
    [_5]="0x35"       [_6]="0x36"       [_7]="0x37"       [_8]="0x38"
    [_9]="0x39"       [_:]="0x3a"       [_\;]="0x3b"      [_\<]="0x3c"
    [_=]="0x3d"       [_\>]="0x3e"      [_\?]="0x3f"      [_@]="0x40"
    [_A]="0x41"       [_B]="0x42"       [_C]="0x43"       [_D]="0x44"
    [_E]="0x45"       [_F]="0x46"       [_G]="0x47"       [_H]="0x48"
    [_I]="0x49"       [_J]="0x4a"       [_K]="0x4b"       [_L]="0x4c"
    [_M]="0x4d"       [_N]="0x4e"       [_O]="0x4f"       [_P]="0x50"
    [_Q]="0x51"       [_R]="0x52"       [_S]="0x53"       [_T]="0x54"
    [_U]="0x55"       [_V]="0x56"       [_W]="0x57"       [_X]="0x58"
    [_Y]="0x59"       [_Z]="0x5a"       [_\[]="0x5b"      #[_\\]="0x5c"
    #[_\]]="0x5d"
                      [_\^]="0x5e"      [__]="0x5f"       [_\`]="0x60"
    [_a]="0x61"       [_b]="0x62"       [_c]="0x63"       [_d]="0x64"
    [_e]="0x65"       [_f]="0x66"       [_g]="0x67"       [_h]="0x68"
    [_i]="0x69"       [_j]="0x6a"       [_k]="0x6b"       [_l]="0x6c"
    [_m]="0x6d"       [_n]="0x6e"       [_o]="0x6f"       [_p]="0x70"
    [_q]="0x71"       [_r]="0x72"       [_s]="0x73"       [_t]="0x74"
    [_u]="0x75"       [_v]="0x76"       [_w]="0x77"       [_x]="0x78"
    [_y]="0x79"       [_z]="0x7a"       [_\{]="0x7b"      [_\|]="0x7c"
    [_\}]="0x7d"      [_~]="0x7e"       [_$'\177']="0x7f" [_$'\200']="0x80"
    [_$'\201']="0x81" [_$'\202']="0x82" [_$'\203']="0x83" [_$'\204']="0x84"
    [_$'\205']="0x85" [_$'\206']="0x86" [_$'\207']="0x87" [_$'\210']="0x88"
    [_$'\211']="0x89" [_$'\212']="0x8a" [_$'\213']="0x8b" [_$'\214']="0x8c"
    [_$'\215']="0x8d" [_$'\216']="0x8e" [_$'\217']="0x8f" [_$'\220']="0x90"
    [_$'\221']="0x91" [_$'\222']="0x92" [_$'\223']="0x93" [_$'\224']="0x94"
    [_$'\225']="0x95" [_$'\226']="0x96" [_$'\227']="0x97" [_$'\230']="0x98"
    [_$'\231']="0x99" [_$'\232']="0x9a" [_$'\233']="0x9b" [_$'\234']="0x9c"
    [_$'\235']="0x9d" [_$'\236']="0x9e" [_$'\237']="0x9f" [_$'\240']="0xa0"
    [_$'\241']="0xa1" [_$'\242']="0xa2" [_$'\243']="0xa3" [_$'\244']="0xa4"
    [_$'\245']="0xa5" [_$'\246']="0xa6" [_$'\247']="0xa7" [_$'\250']="0xa8"
    [_$'\251']="0xa9" [_$'\252']="0xaa" [_$'\253']="0xab" [_$'\254']="0xac"
    [_$'\255']="0xad" [_$'\256']="0xae" [_$'\257']="0xaf" [_$'\260']="0xb0"
    [_$'\261']="0xb1" [_$'\262']="0xb2" [_$'\263']="0xb3" [_$'\264']="0xb4"
    [_$'\265']="0xb5" [_$'\266']="0xb6" [_$'\267']="0xb7" [_$'\270']="0xb8"
    [_$'\271']="0xb9" [_$'\272']="0xba" [_$'\273']="0xbb" [_$'\274']="0xbc"
    [_$'\275']="0xbd" [_$'\276']="0xbe" [_$'\277']="0xbf" [_$'\300']="0xc0"
    [_$'\301']="0xc1" [_$'\302']="0xc2" [_$'\303']="0xc3" [_$'\304']="0xc4"
    [_$'\305']="0xc5" [_$'\306']="0xc6" [_$'\307']="0xc7" [_$'\310']="0xc8"
    [_$'\311']="0xc9" [_$'\312']="0xca" [_$'\313']="0xcb" [_$'\314']="0xcc"
    [_$'\315']="0xcd" [_$'\316']="0xce" [_$'\317']="0xcf" [_$'\320']="0xd0"
    [_$'\321']="0xd1" [_$'\322']="0xd2" [_$'\323']="0xd3" [_$'\324']="0xd4"
    [_$'\325']="0xd5" [_$'\326']="0xd6" [_$'\327']="0xd7" [_$'\330']="0xd8"
    [_$'\331']="0xd9" [_$'\332']="0xda" [_$'\333']="0xdb" [_$'\334']="0xdc"
    [_$'\335']="0xdd" [_$'\336']="0xde" [_$'\337']="0xdf" [_$'\340']="0xe0"
    [_$'\341']="0xe1" [_$'\342']="0xe2" [_$'\343']="0xe3" [_$'\344']="0xe4"
    [_$'\345']="0xe5" [_$'\346']="0xe6" [_$'\347']="0xe7" [_$'\350']="0xe8"
    [_$'\351']="0xe9" [_$'\352']="0xea" [_$'\353']="0xeb" [_$'\354']="0xec"
    [_$'\355']="0xed" [_$'\356']="0xee" [_$'\357']="0xef" [_$'\360']="0xf0"
    [_$'\361']="0xf1" [_$'\362']="0xf2" [_$'\363']="0xf3" [_$'\364']="0xf4"
    [_$'\365']="0xf5" [_$'\366']="0xf6" [_$'\367']="0xf7" [_$'\370']="0xf8"
    [_$'\371']="0xf9" [_$'\372']="0xfa" [_$'\373']="0xfb" [_$'\374']="0xfc"
    [_$'\375']="0xfd" [_$'\376']="0xfe" [_$'\377']="0xff"
  )
  function ord_eascii3 {
        local -i val="${EAsciiLookup2["_${2:0:1}"]-}"
        if [ "${val}" -eq 0 ]; then
                case "${2:0:1}" in
                        ])  val=0x5d ;;
                        \\) val=0x5c ;;
                esac
        fi
        eval "${1}"'="${val}"'
  }
  # for fun check out the following
  time for (( i=0 ; i <1000; i++ )); do ord TmpVar 'a'; done
  #  real 0m0.065s
  #  user 0m0.048s
  #  sys  0m0.000s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii TmpVar 'a'; done
  #  real 0m0.239s
  #  user 0m0.188s
  #  sys  0m0.000s

  time for (( i=0 ; i <1000; i++ )); do ord_utf8 TmpVar 'a'; done
  #  real       0m0.225s
  #  user       0m0.180s
  #  sys        0m0.000s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii2 TmpVar 'a'; done
  #  real 0m1.507s
  #  user 0m1.056s
  #  sys  0m0.012s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii3 TmpVar 'a'; done
  #  real 0m0.147s
  #  user 0m0.120s
  #  sys  0m0.000s

  time for (( i=0 ; i <1000; i++ )); do ord_echo 'a' >/dev/null ; done
  #  real       0m0.065s
  #  user       0m0.044s
  #  sys        0m0.016s

  time for (( i=0 ; i <1000; i++ )); do ord_eascii_echo 'a' >/dev/null ; done
  #  real       0m0.089s
  #  user       0m0.068s
  #  sys        0m0.008s

  time for (( i=0 ; i <1000; i++ )); do ord_utf8_echo 'a' >/dev/null ; done
  #  real       0m0.226s
  #  user       0m0.172s
  #  sys        0m0.012s

Here are some older, simpler functions that do similar things: 

# POSIX
# chr() - converts decimal value to its ASCII character representation
# ord() - converts ASCII character to its decimal value

chr() {
  [ ${1} -lt 256 ] || return 1
  printf \\$(printf '%03o' $1)
}

# Another version doing the octal conversion with arithmetic
# faster as it avoids a subshell
chr () {
  [ ${1} -lt 256 ] || return 1
  printf \\$(($1/64*100+$1%64/8*10+$1%8))
}

# Another version using a temporary variable to avoid subshell.
# This one requires bash 3.1.
chr() {
  local tmp
  [ ${1} -lt 256 ] || return 1
  printf -v tmp '%03o' "$1"
  printf \\"$tmp"
}

ord() {
  printf '%d' "'$1"
}

# hex() - converts ASCII character to a hexadecimal value
# unhex() - converts a hexadecimal value to an ASCII character

hex() {
   printf '%x' "'$1"
}

unhex() {
   printf \\x"$1"
}

# examples:

chr $(ord A)    # -> A
ord $(chr 65)   # -> 65

The ord function above is quite tricky.

  • Tricky? Rather, it's using a feature that I can't find documented anywhere -- putting a single quote in front of an integer. Neat effect, but how on earth did you find out about it? Source diving? -- GreyCat

    • It validates The Single Unix Specification: "If the leading character is a single-quote or double-quote, the value shall be the numeric value in the underlying codeset of the character following the single-quote or double-quote." (see printf() to know more) -- mjf

    $'\357\277\277'
    • printf "%q\n" "$(chr.utf8.echo 0x100)" # =

BashFAQ/071 (last edited 2021-02-08 16:03:51 by GreyCat)