## I cannot compile st in OpenBSD
-OpenBSD lacks of librt, but it is mandatory in POSIX
+OpenBSD lacks of librt, despite it begin mandatory in POSIX
<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html#tag_20_11_13>.
-If you want compile st for OpenBSD you have to remove -lrt from config.mk, and
-st will compile without any loss of functionality because all the functions are
+If you want to compile st for OpenBSD you have to remove -lrt from config.mk, and
+st will compile without any loss of functionality, because all the functions are
included in libc on this platform.
+## Backspace key does not work
+
+This is an issue that was discussed in suckless mailing list
+<http://lists.suckless.org/dev/1404/20697.html>:
+
+ Well, I am going to comment why I want to change the behaviour
+ of this key. When ASCII was defined in 1968, communication
+ with computers was done using punched cards, or hardcopy
+ terminals (basically a typewriter machine connected with the
+ computer using a serial port). ASCII defines DELETE as 7F,
+ because, in punched-card terms, it means all the holes of the
+ card punched; it is thus a kind of 'physical delete'. In the
+ same way, the BACKSPACE key was a non-destructive backspace,
+ as on a typewriter. So, if you wanted to delete a character,
+ you had to BACKSPACE and then DELETE. Another use of BACKSPACE
+ was to type accented characters, for example 'a BACKSPACE `'.
+ The VT100 had no BACKSPACE key; it was generated using the
+ CONTROL key as another control character (CONTROL key sets to
+ 0 b7 b6 b5, so it converts H (code 0x48) into BACKSPACE (code
+ 0x08)), but it had a DELETE key in a similar position where
+ the BACKSPACE key is located today on common PC keyboards.
+ All the terminal emulators emulated the difference between
+ these keys correctly: the backspace key generated a BACKSPACE
+ (^H) and delete key generated a DELETE (^?).
+
+ But a problem arose when Linus Torvalds wrote Linux. Unlike
+ earlier terminals, the Linux virtual terminal (the terminal
+ emulator integrated in the kernel) returned a DELETE when
+ backspace was pressed, due to the VT100 having a DELETE key in
+ the same position. This created a lot of problems (see [1]
+ and [2]). Since Linux has become the king, a lot of terminal
+ emulators today generate a DELETE when the backspace key is
+ pressed in order to avoid problems with Linux. The result is
+ that the only way of generating a BACKSPACE on these systems
+ is by using CONTROL + H. (I also think that emacs had an
+ important point here because the CONTROL + H prefix is used
+ in emacs in some commands (help commands).)
+
+ From point of view of the kernel, you can change the key
+ for deleting a previous character with stty erase. When you
+ connect a real terminal into a machine you describe the type
+ of terminal, so getty configures the correct value of stty
+ erase for this terminal. In the case of terminal emulators,
+ however, you don't have any getty that can set the correct
+ value of stty erase, so you always get the default value.
+ For this reason, it is necessary to add 'stty erase ^H' to your
+ profile if you have changed the value of the backspace key.
+ Of course, another solution is for st itself to modify the
+ value of stty erase. I usually have the inverse problem:
+ when I connect to non-Unix machines, I have to press CONTROL +
+ h to get a BACKSPACE. The inverse problem occurs when a user
+ connects to my Unix machines from a different system with a
+ correct backspace key.
+
+ [1] http://www.ibb.net/~anne/keyboard.html
+ [2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
+
Got questions, comments, patches, etc.? Contact Jason Woofenden