sed commands
The character "#" is a command (which cannot have any address)
Ths is useful if the sed-program is stored in a file. The whole program can be executed with
bash$ sed -f programfile < inputdata
The "{" and "}" commands group different commands.
"}" is a command --> it must be preceded by a semicolon.
bash$ sed -ne '/gimme this line number/{=;q;}'
The command "n" reads a new line from stdin
/skip this line/{d;n;}
# do some ugly stuff
...