How do I use the extended ASCII character set in the text console in Red Hat Enterprise Linux 5?

Environment

• Red Hat Enterprise Linux(RHEL) 5

Solution

To be able to see these extended characters on text console, one must disable unicode support for the console and switch character encoding to CP437. It can be done by running the following commands as root:

root@localhost# unicode_stop
root@localhost# setfont default8x16
root@localhost# setfont -m cp437

Note

The extended ASCII character set was used to display window borders and other non-ASCII artifacts in legacy console applications. There is however, no formal standard around it, due to which it should be considered deprecated in favour of standard character sets such as UTF-8. It is hence recommended that application developers avoid use of this character set and instead use UTF-8. One could get the UTF-8 equivalent of a character in an extended ASCII character set in the following manner:

1) Dump the desired character(s) into a file:

foo@localhost$ printf "\303\n" > mychar.txt

2) Convert the file using iconv:

foo@localhost$ iconv -f CP437 -t UTF-8 -o mychar-utf8.txt mychar.txt

3) Get the octal dump of the converted file to get octal code for the UTF-8 equivalent:

foo@localhost$ od -c mychar-utf8.txt

Note that the output UTF-8 character code may span across multiple bytes, so one should cater for multibyte characters in their application when using UTF-8. To do this conveniently and in a cross-platform manner, one may use Unicode string handling functions in the GNU glib2 library.