Searching for shell builtins to speedup Nanoblogger, we stumbled across
a very charming and nice way to implement a tail function in the
Kornshell.
This works in KSH93 and newer.
The new redirection operators, <# and ># are used to seek. For
example,
<# (( EOF-36 ))
will seek to 36 bytes before the end-of-file. You can apply this along with any redirection so that
cat < file <# (( 80 ))
will cat the file starting from offset 80. The value of $(n<#) is the
current offset on file descriptor n.
The current syntax can be extended to add other seek options like
SEEK_HOLE, by using,
<# (( HOLE ))
to seek to the next hole.