diff options
| -rw-r--r-- | doc/pid.n | 15 | ||||
| -rw-r--r-- | doc/tell.n | 16 |
2 files changed, 29 insertions, 2 deletions
@@ -5,7 +5,7 @@ '\" 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 1.3 2000/09/07 14:27:50 poenitz Exp $ +'\" RCS: @(#) $Id: pid.n,v 1.4 2004/05/28 12:40:29 dkf Exp $ '\" .so man.macros .TH pid n 7.0 Tcl "Tcl Built-In Commands" @@ -29,6 +29,19 @@ that isn't 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: + +.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) @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: tell.n,v 1.5 2001/09/14 19:20:40 andreas_kupries Exp $ +'\" RCS: @(#) $Id: tell.n,v 1.6 2004/05/28 12:48:36 dkf Exp $ '\" .so man.macros .TH tell n 8.1 Tcl "Tcl Built-In Commands" @@ -34,6 +34,20 @@ Tcl standard channel (\fBstdin\fR, \fBstdout\fR, or \fBstderr\fR), the return value from an invocation of \fBopen\fR or \fBsocket\fR, or the result of a channel creation command provided by a Tcl extension. .VE +.SH EXAMPLE +Read a line from a file channel only if it starts with \fBfoobar\fR: + +.CS +# Save the offset in case we need to undo the read... +set offset [\fBtell\fR $chan] +if {[read $chan 6] eq "foobar"} { + gets $chan line +} else { + set line {} + # Undo the read... + seek $chan $offset +} +.CE .SH "SEE ALSO" file(n), open(n), close(n), gets(n), seek(n), Tcl_StandardChannels(3) |