pid — Retrieve process identifiers
pid ?fileId?
If the fileId argument is given then it should normally
refer to a process pipeline created with the open command. In this case the
pid command will return a list whose elements are the
process identifiers of all the processes in the pipeline, in order.
The list will be empty if fileId refers to an open file that
is not a process pipeline. If no fileId argument is given
then pid returns the process identifier of the current
process. All process identifiers are returned as decimal strings.
Print process information about the processes in a pipeline using
the SysV ps program before reading the output of that
pipeline:
set pipeline [open "| zcat somefile.gz | grep foobar | sort -u"]
# Print process information
exec ps -fp [pid $pipeline] >@stdout
# Print a separator and then the output of the pipeline
puts [string repeat - 70]
puts [read $pipeline]
close $pipeline
exec, open
file, pipeline, process identifier
Copyright © 1993 The Regents of the University of
California.
Copyright © 1994-1996 Sun Microsystems, Inc.