<HTML><HEAD><TITLE>Tcl Built-In Commands - pid manual page</TITLE></HEAD><BODY> <H3><A NAME="M2">NAME</A></H3> pid - Retrieve process id(s) <H3><A NAME="M3">SYNOPSIS</A></H3> <B>pid </B>?<I>fileId</I>?<BR> <H3><A NAME="M4">DESCRIPTION</A></H3> If the <I>fileId</I> argument is given then it should normally refer to a process pipeline created with the <B><A HREF="../TkCmd/open.htm">open</A></B> command. In this case the <B>pid</B> 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 <I>fileId</I> refers to an open file that isn't a process pipeline. If no <I>fileId</I> argument is given then <B>pid</B> returns the process identifier of the current process. All process identifiers are returned as decimal strings. <H3><A NAME="M5">SEE ALSO</A></H3> <B><A HREF="../TkCmd/exec.htm">exec</A></B>, <B><A HREF="../TkCmd/open.htm">open</A></B> <H3><A NAME="M6">KEYWORDS</A></H3> <A href="../Keywords/F.htm#file">file</A>, <A href="../Keywords/P.htm#pipeline">pipeline</A>, <A href="../Keywords/P.htm#process identifier">process identifier</A> <HR><PRE> <A HREF="../copyright.htm">Copyright</A> © 1993 The Regents of the University of California. <A HREF="../copyright.htm">Copyright</A> © 1994-1996 Sun Microsystems, Inc. <A HREF="../copyright.htm">Copyright</A> © 1995-1997 Roger E. Critchlow Jr.</PRE> </BODY></HTML>