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Appendix R. ASCII Table
In a book of this sort it is traditional to have an
ASCII Table appendix. This book does not. Instead, here is a short
shell script that generates a complete ASCII table and writes it
to the file ASCII.txt.
Example R-1. A script that generates an ASCII table
#!/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. |