@itemx --pid=@var{pid}
@opindex --pid
-When following by name or by descriptor, you may specify the process ID
-@var{pid} of the sole writer of all @var{file} arguments. Then, when that
-process terminates, tail will also terminate. For this to work properly,
-the tail process and the writer must be on the same machine and the tail
-process must be able to send a signal to the writing process (but does
-not actually send any signal). For example, to save the output of a
-build in a file and to watch the file grow, if you invoke @code{make}
-and @code{tail} like this then the tail process will stop when your
-build completes. Without this option, you would have had to kill the
-@code{tail -f} process yourself.
+When following by name or by descriptor, you may specify the process ID,
+@var{pid}, of the sole writer of all @var{file} arguments. Then, shortly
+after that process terminates, tail will also terminate. This will work
+properly only if the tailing process and the writer are on the same
+machine and the tailing process is able to send signals to the writing
+process (@code{tail} does not actually send any signal). For example,
+to save the output of a build in a file and to watch the file grow, if
+you invoke @code{make} and @code{tail} like this then the tail process
+will stop when your build completes. Without this option, you would
+have had to kill the @code{tail -f} process yourself.
@example
-make >& makerr & tail --pid=$! -f makerr
+$ make >& makerr & tail --pid=$! -f makerr
@end example
If you specify a @var{pid} that is not in use or that does not correspond
to the process that is writing to the tailed files, then @code{tail}