eof is, in one sense, a command:

http://purl.org/tcl/home/man/tcl8.4/TclCmd/eof.htm

and, in another sense, an acronym for ''End Of File''.
----

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, and avoid eof's
[FMM]
[http://phaseit.net/claird/comp.lang.tcl/fmm.html#eof] by coding:
 while {[gets $fp line]>=0} {...}
instead of
 while {![eof $fp]} {
    gets $fp line
    if [eof $fp break] ;# otherwise loops one time too many
    ...
 } ;# RS  
----
Hmmm... the only thing I find eof good for is as a condition
which should trigger closing a socket.

That is, if you are trying to read a non-blocking socket and
you hit eof, you KNOW that it's time to close the socket.

'''-PSE'''
----
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?

[JMN] 2003-07-15 This isn't directly referring to the eof command - but is an EOF issue that I wasn't expecting so here looks as good a place as any to mention it.

Using the Memchan package, I was trying to fcopy from a memchan to a file roughly like so:
 set m [memchan]
 puts $m "someStringData"
 seek $m 0 start
 fcopy $m $fd -command CopyFinished
 
 proc CopyFinished args { ... }

This performed the copy to file just fine, but the CopyFinished proc never got called.
To fix this, I called 
 fconfigure $m -eofchar {}
before the puts line.. and
 fconfigure $m -eofchar \x1a
before the fcopy line.
Then I changed the puts line to:
 puts $m "someStringData\x1a"

This seems like a bit of hoop-jumping to get the expected fcopy behaviour.. am I missing something simple?









----
[Tcl syntax help]
- [Arts and crafts of Tcl-Tk programming]
- [Category Command]