Commands that use a line range:
If no line is given, then curent line is printed.

p    Print line.
d    Delete line.
l    Print line with control characters.
r file    Read in a file after the line specified.
s    Substitute patterns. See special documentation.
z    Print 10 lines.
a    Start insert mode after specified line. Exit with '.'<return>.
i    Start insert mode before specified line. Exit with '.'<return>.

Commands used without line specification:

q    Quit. Won't work if file is changed.
Q    Quit and discard all changes if not saved.
w    Write the file out.
w file    Write the file out with name 'file'.
e file    Edit a file.

As line numbers '.' is current line, and '$' is last line of file.
Thus '1,$p' will always print all of the file.
