chapter: ASCII Table, geneate your own

Author: pmarinov

index.ptree

@@ -126,6 +126,7 @@ pages/bibliography.poly.pm
   pages/completion_intro.poly.pm
   pages/localization.poly.pm
   pages/sample_bashrc.poly.pm
+  pages/ascii_table.poly.pm
 }
 
 }

pages/ascii_table.poly.pm

@@ -0,0 +1,152 @@
+#lang pollen
+
+◊page-init{}
+◊define-meta[page-title]{ASCII Table}
+◊define-meta[page-description]{Generate your own ASCII Table}
+
+Traditionally, a book of this sort has an ASCII Table appendix. This
+book does not. Instead, here are several short scripts, each of which
+generates a complete ASCII table.
+
+◊anchored-example[#:anchor "ascii1"]{A script that generates an ASCII
+table}
+
+◊example{
+#!/bin/bash
+# ascii.sh
+# ver. 0.2, reldate 26 Aug 2008
+# Patched by ABS Guide author.
+
+# Original script by Sebastian Arming.
+# Used with permission (thanks!).
+
+exec >ASCII.txt         #  Save stdout to file,
+                        #+ as in the example scripts
+                        #+ reassign-stdout.sh and upperconv.sh.
+
+MAXNUM=256
+COLUMNS=5
+OCT=8
+OCTSQU=64
+LITTLESPACE=-3
+BIGSPACE=-5
+
+i=1 # Decimal counter
+o=1 # Octal counter
+
+while [ "$i" -lt "$MAXNUM" ]; do  # We don't have to count past 400 octal.
+        paddi="    $i"
+        echo -n "${paddi: $BIGSPACE}  "       # Column spacing.
+        paddo="00$o"
+#       echo -ne "\\${paddo: $LITTLESPACE}"   # Original.
+        echo -ne "\\0${paddo: $LITTLESPACE}"  # Fixup.
+#                   ^
+        echo -n "     "
+        if (( i % $COLUMNS == 0)); then       # New line.
+           echo
+        fi
+        ((i++, o++))
+        # The octal notation for 8 is 10, and 64 decimal is 100 octal.
+        (( i % $OCT == 0))    && ((o+=2))
+        (( i % $OCTSQU == 0)) && ((o+=20))
+done
+
+exit $?
+
+# Compare this script with the "pr-asc.sh" example.
+# This one handles "unprintable" characters.
+
+# Exercise:
+# Rewrite this script to use decimal numbers, rather than octal.
+}
+
+◊anchored-example[#:anchor "ascii2"]{Another ASCII table script}
+
+◊example{
+#!/bin/bash
+# Script author: Joseph Steinhauser
+# Lightly edited by ABS Guide author, but not commented.
+# Used in ABS Guide with permission.
+
+#-------------------------------------------------------------------------
+#-- File:  ascii.sh    Print ASCII chart, base 10/8/16         (JETS-2012)
+#-------------------------------------------------------------------------
+#-- Usage: ascii [oct|dec|hex|help|8|10|16]
+#--
+#-- This script prints out a summary of ASCII char codes from Zero to 127.
+#-- Numeric values may be printed in Base10, Octal, or Hex.
+#--
+#-- Format Based on: /usr/share/lib/pub/ascii with base-10 as default.
+#-- For more detail, man ascii . . .
+#-------------------------------------------------------------------------
+
+[ -n "$BASH_VERSION" ] && shopt -s extglob
+
+case "$1" in
+   oct|[Oo]?([Cc][Tt])|8)       Obase=Octal;  Numy=3o;;
+   hex|[Hh]?([Ee][Xx])|16|[Xx]) Obase=Hex;    Numy=2X;;
+   help|?(-)[h?])        sed -n '2,/^[ ]*$/p' $0;exit;;
+   code|[Cc][Oo][Dd][Ee])sed -n '/case/,$p'   $0;exit;;
+   *) Obase=Decimal
+esac # CODE is actually shorter than the chart!
+
+printf "\t\t## $Obase ASCII Chart ##\n\n"; FM1="|%0${Numy:-3d}"; LD=-1
+
+AB="nul soh stx etx eot enq ack bel bs tab nl vt np cr so si dle"
+AD="dc1 dc2 dc3 dc4 nak syn etb can em sub esc fs gs rs us sp"
+
+for TOK in $AB $AD; do ABR[$((LD+=1))]=$TOK; done;
+ABR[127]=del
+
+IDX=0
+while [ $IDX -le 127 ] && CHR="${ABR[$IDX]}"
+   do ((${#CHR}))&& FM2='%-3s'|| FM2=`printf '\\\\%o  ' $IDX`
+      printf "$FM1 $FM2" "$IDX" $CHR; (( (IDX+=1)%8))||echo '|'
+   done
+
+exit $?
+}
+
+◊anchored-example[#:anchor "ascii3"]{A third ASCII table script, using
+awk}
+
+◊example{
+#!/bin/bash
+# ASCII table script, using awk.
+# Author: Joseph Steinhauser
+# Used in ABS Guide with permission.
+
+
+#-------------------------------------------------------------------------
+#-- File:  ascii     Print ASCII chart, base 10/8/16         (JETS-2010)
+#-------------------------------------------------------------------------
+#-- Usage: ascii [oct|dec|hex|help|8|10|16]
+#--
+#-- This script prints a summary of ASCII char codes from Zero to 127.
+#-- Numeric values may be printed in Base10, Octal, or Hex (Base16).
+#--
+#-- Format Based on: /usr/share/lib/pub/ascii with base-10 as default.
+#-- For more detail, man ascii
+#-------------------------------------------------------------------------
+
+[ -n "$BASH_VERSION" ] && shopt -s extglob
+
+case "$1" in
+   oct|[Oo]?([Cc][Tt])|8)       Obase=Octal;  Numy=3o;;
+   hex|[Hh]?([Ee][Xx])|16|[Xx]) Obase=Hex;    Numy=2X;;
+   help|?(-)[h?])        sed -n '2,/^[ ]*$/p' $0;exit;;
+   code|[Cc][Oo][Dd][Ee])sed -n '/case/,$p'   $0;exit;;
+   *) Obase=Decimal
+esac
+export Obase   # CODE is actually shorter than the chart!
+
+awk 'BEGIN{print "\n\t\t## "ENVIRON["Obase"]" ASCII Chart ##\n"
+           ab="soh,stx,etx,eot,enq,ack,bel,bs,tab,nl,vt,np,cr,so,si,dle,"
+           ad="dc1,dc2,dc3,dc4,nak,syn,etb,can,em,sub,esc,fs,gs,rs,us,sp"
+           split(ab ad,abr,",");abr[0]="nul";abr[127]="del";
+           fm1="|%0'"${Numy:- 4d}"' %-3s"
+           for(idx=0;idx<128;idx++){fmt=fm1 (++colz%8?"":"|\n")
+           printf(fmt,idx,(idx in abr)?abr[idx]:sprintf("%c",idx))} }'
+
+exit $?
+}