Tools for dealing with encoding and receipt printers

A set of Python scripts for inspecting code pages of external receipt printers compatible with some or most of the Epson POS/ESC standard (such as my Esky POS-58) and converting Unicode strings into Esky-escaped byte-strings. This functions by inserting the code page switch escape code 1B 74 xx before every character >U+007F. This repository contains the closely-related but previously separate scripts from test-encoding, which I considered too closely related to be worth keeping separate. A brief index of the scripts and their uses follows.

Install with

pip install uni2esky

Which will install the uni2esky and encodingutils modules as well as the following commands:

• codepages
• testencoding
• uni2esky
• udat2dict

Table of Contents

1. Tools for dealing with encoding and receipt printers
2. Table of Contents
3. The scripts
   1. Generic — encodingutils
      1. encodingutils.char
      2. encodingutils.codepages — Exposed globally as codepages
      3. encodingutils.testencoding — Exposed globally as testencoding
   2. Esky-Specific — uni2esky
      1. uni2esky (= uni2esky.uni2esky) — Exposed globally as uni2esky
      2. uni2esky.dat (and uni2esky.regen_map and uni2esky.eskymap)
      3. uni2esky.list_chars
      4. uni2esky.rand
      5. uni2esky.udat2dictkeys — Exposed globally as udat2dict
      6. strescpos.esc

The scripts

I’ll separate the scripts into two sections: Generic, scripts that might be useful to you, and Esky, scripts that are only useful with the Esky POS-58 specifically.

Only a couple scripts have global entry points that are auto-installed with the package. For other modules, e.g. encodingutils.char, you may use the python -m encodingutils.char ... syntax.

Generic — encodingutils

encodingutils.char

Outputs a single code point from a given code page / code position pair. To output codepoint 0xa2 from codepage 95 (decimal), run ./char.py 95 0xa2. Unpolished and rarely useful.

Contains encodingutils.char.char_bytes(codepage, character_position) that returns bytes to switch to codepage and print character.

encodingutils.codepages — Exposed globally as codepages

Prints guides to codepages. Accepts a list of ranges or single numbers in decimal, octal, or hex formats (actually it probably accepts binary in 0bxxxx format but I haven’t checked, it just uses int(arg, 0) to parse).

A list of arguments might look something like codepages 1 5 7-11 0x40 080-230 (but don’t actually mix number formats like that).

$ codepages.py 4-5

  codepage 0x4 = 4
  0123456789abcdef
  ----------------
8 ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 8
9 ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 9
a ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ a
b ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ b
c ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ c
d ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ d
e ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ e
f ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ f
  ----------------
  0123456789abcdef
++++++++++++++++++++++++++++++++
  codepage 0x5 = 5
PuTTY  0123456789abcdef
  ----------------
8 ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 8
9 ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ 9
a ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ a
b ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ b
c ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ c
d ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ d
e ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ e
f ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ f
  ----------------
  0123456789abcdef

encodingutils.testencoding — Exposed globally as testencoding

Use testencoding -r to print raw bytes 0x00 through 0xff to STDOUT. Can be piped to, e.g., lpr -l to inspect the codepage of an external device.

$ testencoding

  0123456789abcdef
  ----------------
0  ☺☻♥♦♣
♫☼ 0
1 ►◄↕‼¶§■↨↑↓→←∟↔▲▼ 1
2  !"#$%&'()*+,-./ 2
3 0123456789:;<=>? 3
4 @ABCDEFGHIJKLMNO 4
5 PQRSTUVWXYZ[\]^_ 5
6 `abcdefghijklmno 6
7 pqrstuvwxyz{|}~� 7
8 ���������������� 8
9 ���������������� 9
a  ¡¢£¤¥¦§¨©ª«¬­®¯ a
b °±²³´µ¶·¸¹º»¼½¾¿ b
c ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏ c
d ÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞß d
e àáâãäåæçèéêëìíîï e
  ----------------
  0123456789abcdef

Esky-Specific — uni2esky

uni2esky (= uni2esky.uni2esky) — Exposed globally as uni2esky

This is the most important script of the bunch. It has two functions:

1. Use as a Python module to encode text to Esky-escapes.
2. Use as a command-line script to encode text to Esky-escapes.

Example usage for the first:

import uni2esky

out = uni2esky.encode(input_text)

For the second:

./maze.py | uni2esky | lpr -l

uni2esky.dat (and uni2esky.regen_map and uni2esky.eskymap)

Not really a script. Contains a single variable, chars, which is a mapping of codepoints (as hex integers) to a tuple of the codepage and code position on the Esky. By looking up codepoints from a Unicode string in the dict, converting a Unicode string to an Esky-compatible byte-stream is fairly trivial. Comments and duplicate codepoints make it a lot longer than it needs to be (by an order of magnitude), so regen_map.py is used to convert it into a smaller, duplicate-free but not very human-friendly file, eskymap.py.

Do not import dat ever — always use eskymap if necessary, but generally only uni2esky is useful — eskymap is just the infra.

uni2esky.list_chars

Prints all the characters in eskymap.py. There are about 950 as of the writing of this text.

$ ./list_chars.py

¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæç
èéêëìíîïðñòóôõö÷øùúûüýþÿĀāĂ㥹ĆćČčĎďĐđĒēĖėĘęĚěĞğĢģĪīĮįİıĶķĹĺĻļĽľŁłŃńŅņ
ŇňŌōŐőŒœŔŕŖŗŘřŚśŞşŠšŢţŤťŪūŮůŰűŲųŸŹźŻżŽžƒƠơƯưˆˇ˘˙˛˜˝̣̀́̃̉΄΅Ά·ΈΉΊΌΎΏΐΑΒΓΔΕ
ΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩΪΫάέήίΰαβγδεζηθικλμνξοπρςστυφχψωϊϋόύώϕЁЂЃЄЅІЇЈЉЊ
ЋЌЎЏАБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯабвгдежзийклмнопрстуфхцчшщъыьэю
яёђѓєѕіїјљњћќўџҐґְֱֲֳִֵֶַָֹֻּֽ־ֿ׀ׁׂ׃אבגדהוזחטיךכלםמןנסעףפץצקרשתװױײ،؛؟ءآأؤإئابةتثجحخ
دذرزسشصضطظعغـفقكلمنهوىيًٌٍَُِّْ٠١٢٣٤٥٦٧٨٩پچژگ–—―‗‘’‚“”„†‡•…‰‹›‾ⁿ₧₪₫€№™∙√∞
∩≈≡≤≥⌐⌠⌡─│┌┐└┘├┤┬┴┼═║╒╓╔╕╖╗╘╙╚╛╜╝╞╟╠╡╢╣╤╥╦╧╨╩╪╫╬╭╮╯╰╱╲╳▀▁▂▃▄▅▆▇█▉▊▋▌▍▎
▏▐░▒▓▔▕■○●◢◣◤◥♠♣♥♦「」ﭖﭘﭺﭼﮊﮒﮔﹰﹱﹲﹴﹶﹷﹸﹹﹺﹻﹼﹽﹾﹿﺀﺁﺂﺃﺄﺅﺆﺇﺈﺉﺊﺋﺌﺍﺎﺏﺐﺑﺒﺓﺔﺕﺖﺗﺘﺙﺚﺛﺜ
ﺝﺞﺟﺠﺡﺢﺣﺤﺥﺦﺧﺨﺩﺪﺫﺬﺭﺮﺯﺰﺱﺲﺳﺴﺵﺶﺷﺸﺹﺺﺻﺼﺽﺾﺿﻀﻁﻂﻃﻄﻅﻆﻇﻈﻉﻊﻋﻌﻍﻎﻏﻐﻑﻒﻓﻔﻕﻖﻗﻘﻙﻚﻛﻜﻝﻞﻟ
ﻠﻡﻢﻣﻤﻥﻦﻧﻨﻩﻪﻫﻬﻭﻮﻯﻰﻱﻲﻳﻴﻵﻶﻷﻸﻹﻺﻻﻼ｡｢｣､･ｦｧｨｩｪｫｬｭｮｯｰｱｲｳｴｵｶｷｸｹｺｻｼｽｾｿﾀﾁﾂﾃﾄﾅﾆ
ﾇﾈﾉﾊﾋﾌﾍﾎﾏﾐﾑﾒﾓﾔﾕﾖﾗﾘﾙﾚﾛﾜﾝﾞﾟ￨￭

uni2esky.rand

Prints random characters from eskymap.py. Not very useful but very cool.

$ ./rand.py 140
نƯذﾒﻘﻉćÜوПŖŁﺘψﻴôⁿﹼÉΝ�ﻧ·ﾄءļмŸحΧШЇ▎ЇĂ”˙ŠыﻩﺭЏｿ١ׂ₪ﺒˆءﹰìַŗмÛƠﺍﻳֹЯΧžÊ¥○Ô�ěֵŸֲĎﭘÒ◤ﻂ
ã╞ｶ٥ﾓψ」Ćз」گļ٩╝άֱﻮﻒח▕ﮒ░ﺞ—｢зВ╬پ·ﺙ―ﻞ⌠●‎¶ŹﻟĪ˙ϋ≤ﻐŰŕﻘ‰ﺥ�ﾁﾏΙ┘ď�ä▄ﾐ∞џ▌ְţ

uni2esky.udat2dictkeys — Exposed globally as udat2dict

This confusingly-named file finds and parses .UDMAP100 files from IBM’s Character Data Conversion Tables into dict-keys ready to be pasted into dat.py. Just read the ./udat2dictkeys.py -h help if you need to use it.

strescpos.esc

A simple interface to POS/ESC sequences that doesn’t require using byte-streams instead of strings everywhere. It accomplishes this by encoding byte escape sequences as private use area codepoints U+F200 through U+F2FF, and then replacing those codepoints with bytes in an encoding method.

Or that’s the idea, at least. Implementation coming soon!