THE 7 bit ASCII CODE
The 7-bit ASCII Code is a permanent part of every PC's ROM BIOS. It defines 128 characters in a 7-bit code, and is formally listed as eight columns each of sixteen characters. The first two columns are the Control Characters that, along with Character 0x7F (DEL) form the Non-printing Characters. The six columns of Printing Characters are conveniently subdivided into Numerics, Upper Case, and Lower Case. Pressing the Control (Ctrl) key with an alphanumeric key moves the output code into the first two columns of Control Characters. The ASCII Code was published by the X 3.4 Committee of the American National Standards Institute in 1968, and is known by different names in different countries. It is recognized internationally as ISO-646.
Files containing only character codes from the ASCII table are known as flat ASCII files to distinguish them from files containing the Extended ASCII Characters (see below) and from Binary Files (also below).
All system files intended to be human-readable and human-editable are flat ASCII files.
Flat ASCII files should not be edited with a word-processor. A commandline text editor (such as mcedit) or graphical programmer's editor (such as nedit) should be used instead.
|American Standard Code For Information Interchange|
THE ASCII CONTROL CODES
The ASCII Control Codes define a basic transmission control protocol and the essential control functions for printers and general storage media.
|ASCII CONTROL CODES|
|NUL||Null||BS||Backspace||DLE||Data Link Escape||CAN||Cancel||SOH||Start of Heading||HT||Horizontal Tab||DC1||Device Control 1||EM||End of Medium||STX||Start of Text||LF||Line Feed||DC2||Device Control 2||SUB||Substitute||ETX||End of Text||VT||Vertical Tab||DC3||Device Control 3||ESC||Escape||EOT||End Of Transmission||FF||Form Feed||DC4||Device Control 4||FS||File Separator||ENQ||Enquiry||CR||Carriage Return||NAK||Negative Acknowledge||GS||Group Separator||ACK||Acknowledge||SO||Shift Out||SYN||Synchronous Idle||RS||Record Separator||BEL||Bell||SI||Shift In||ETB||End Transmission Block||US||Unit Separator|
EXTENDED ASCII CODES
Over the years there have been many proposed extensions to the ASCII character set to fill the remaining 128 cells of an 8-bit (28 = 256) matrix. In recent years, with the move towards internationalization and the inclusion of non-English alphabets and non-Western scripts, The International Standards Organization has issued several standardized character sets. Of these, the most important for English use is the ISO 8859 standard. It includes several 8-bit extensions to the ASCII character set (also known as ISO 646-IRV). Especially important is ISO 8859-1, the "Latin Alphabet No. 1" which has become widely implemented as the de facto ASCII replacement.
ISO 8859-1 supports the following languages: Afrikaans, Basque, Catalan, Danish, Dutch, English, Faeroese, Finnish, French, Galician, German, Icelandic, Irish, Italian, Norwegian, Portuguese, Scottish, Spanish, and Swedish.
Note that the ISO 8859-1 characters are also the first 256 characters of ISO 10646 or Unicode, a 16-bit (216 = 65,536) character set which includes the characters from all languages including Chinese.
The User's shell is the foundation of a personal configuration. Here are suggested contents for the two files used to configure bash. Both are in the User's Home Directory.
# .bashrc # Written by Carl Adams 040307 # Execute the system-wide configuration script if [ -f /etc/bashrc ]; then . /etc/bashrc fi # Create single letter command aliases alias c='eject -t; mount /dev/cdrom' alias f='mount /dev/fd0' alias g='mc -b' alias n='clear' alias o='umount /dev/cdrom; eject -r' alias r='umount /dev/fd0' alias z='mc' # Create modified command aliases alias cp='cp -i' alias ed='mcedit' alias ll='ls -1' alias l.='ls -a' alias lo='ls -1' alias mv='mv -i' alias rm='rm -i' # Configure the command prompt PS1="\[\033[0;36m\[[\W>\\$\[\033[0m\] " export PS1
# .bash_profile # Written by Carl Adams 040307 # Execute the Runtime Configuration script if [ -f ~/.bashrc ]; then . ~/.bashrc fi # Set the User Name USERNAME="root" # Set the Shell search path PATH=$PATH:$HOME/bin:/ace/bin # Identify the Bash Runtime Configuration script BASH_ENV=$HOME/.bashrc # Identify the System text editor EDITOR=mcedit # Export the System Environment strings export USERNAME PATH BASH_ENV EDITOR # Start the X-Windows Graphical Environment startx