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Diffstat (limited to 'doc/pid.n')
| -rw-r--r-- | doc/pid.n | 24 |
1 files changed, 19 insertions, 5 deletions
@@ -5,14 +5,12 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: pid.n,v 1.2 1998/09/14 18:39:54 stanton Exp $ -'\" -.so man.macros .TH pid n 7.0 Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME -pid \- Retrieve process id(s) +pid \- Retrieve process identifiers .SH SYNOPSIS \fBpid \fR?\fIfileId\fR? .BE @@ -25,10 +23,26 @@ In this case the \fBpid\fR 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 \fIfileId\fR refers to an open file -that isn't a process pipeline. +that is not a process pipeline. If no \fIfileId\fR argument is given then \fBpid\fR returns the process identifier of the current process. All process identifiers are returned as decimal strings. +.SH EXAMPLE +Print process information about the processes in a pipeline using the +SysV \fBps\fR program before reading the output of that pipeline: +.PP +.CS +set pipeline [open "| zcat somefile.gz | grep foobar | sort -u"] +# Print process information +exec ps -fp [\fBpid\fR $pipeline] >@stdout +# Print a separator and then the output of the pipeline +puts [string repeat - 70] +puts [read $pipeline] +close $pipeline +.CE + +.SH "SEE ALSO" +exec(n), open(n) .SH KEYWORDS file, pipeline, process identifier |