Since hyperlinks in text output are becoming commonplace (see https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda and https://www.iterm2.com/documentation-escape-codes.html ), it is useful if GNU teseq prints useful info for this escape sequence.

The attached patch does this.

Example:

$ printf '\e]8;;http://www.google.com/\e\\Google\e]8;;\e\\\n' | ./teseq
: Esc ] 8 ;  ; http://www.google.com/
& OSC: OPERATING SYSTEM COMMAND
" Set hyperlink to |http://www.google.com/|
: Esc \
& ST: STRING TERMINATOR
|Google|
: Esc ] 8 ;  ;
& OSC: OPERATING SYSTEM COMMAND
" Set hyperlink to ||
: Esc \
& ST: STRING TERMINATOR
. LF/^J

$ printf '\e]8;id=12;http://www.google.com/\e\\Google\e]8;;\e\\\n' | ./teseq
: Esc ] 8 ; id=12 ; http://www.google.com/
& OSC: OPERATING SYSTEM COMMAND
" Set hyperlink to |http://www.google.com/| with params id=12
: Esc \
& ST: STRING TERMINATOR
|Google|
: Esc ] 8 ;  ;
& OSC: OPERATING SYSTEM COMMAND
" Set hyperlink to ||
: Esc \
& ST: STRING TERMINATOR
. LF/^J

In passing, let me also add support for OSC 0 and OSC 2, which are documented in https://invisible-island.net/xterm/ctlseqs/ctlseqs.html :

$ xtermset -title Foo | teseq
: Esc ] 2 ; Foo
& OSC: OPERATING SYSTEM COMMAND
" Set window title to |Foo|