Version 3 of eof

Programmers can use eof to determine whether the channel has reached the end of input.

Note that it fires only after the last successful gets, so testing for a -1 return value on gets may be a better idea:

 while {[gets $fp line]>=0} {...}

instead of

 while {![eof $fp]} {
    gets $fp line
    if [eof $fp break] ;# otherwise loops one time too many
    ...
 } ;# RS

Can anyone indicate whether there are certain types of channels (pipe, socket, etc.) where eof doesn't do what one might at first blush expect?