tcl7.6 User Commands - gets






NAME

     gets - Read a line from a channel


SYNOPSIS

     gets channelId ?varName?





DESCRIPTION

     This command reads the next  line  from  channelId,  returns
     everything  in  the  line up to (but not including) the end-
     of-line   character(s),   and   discards   the   end-of-line
     character(s).  If varName is omitted the line is returned as
     the result of the command.  If varName is specified then the
     line  is  placed in the variable by that name and the return
     value is a count of the number of characters returned.

     If end of file occurs while scanning for an end of line, the
     command returns whatever input is available up to the end of
     file.  If channelId is in nonblocking mode and there is  not
     a full line of input available, the command returns an empty
     string and does not consume any input.  If varName is speci-
     fied  and  an empty string is returned in varName because of
     end-of-file or because of insufficient data  in  nonblocking
     mode,  then the return count is -1.  Note that if varName is
     not  specified  then  the  end-of-file   and   no-full-line-
     available  cases  can  produce  the same results as if there
     were an  input  line  consisting  only  of  the  end-of-line
     character(s).   The eof and fblocked commands can be used to
     distinguish these three cases.



SEE ALSO

     eof(n), fblocked(n)



KEYWORDS

     blocking, channel, end of file, end of line, line, nonblock-
     ing, read