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Top Forums UNIX for Beginners Questions & Answers Shell script to tail a file with unknown numbers Post 303038784 by RudiC on Friday 13th of September 2019 07:22:06 AM
Old 09-13-2019
Just for the fun of it - how far would this get you:
Code:
FL=$(wc -l < inputfile)
while read
  do    case $REPLY in
        [tT]*)  CMD="NR>$((FL - ${REPLY:1}))";;
        [pP]*)  CMD="/${REPLY:1}/";;
        [fF]*)  CMD=1;;
            *)  echo "usage: CMD Param; CMD ~ t)ail, p)attern search, f)ull"
                continue
        esac

        ((++CNT))
        awk "$CMD" inputfile > /tmp/log.$CNT
  done


Last edited by RudiC; 09-13-2019 at 08:37 AM..
These 2 Users Gave Thanks to RudiC For This Post:
 

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TRACE-CMD-START(1)														TRACE-CMD-START(1)

NAME
trace-cmd-start - start the Ftrace Linux kernel tracer without recording SYNOPSIS
trace-cmd start [OPTIONS] DESCRIPTION
The trace-cmd(1) start enables all the Ftrace tracing the same way trace-cmd-record(1) does. The difference is that it does not run threads to create a trace.dat file. This is useful just to enable Ftrace and you are only interested in the trace after some event has occurred and the trace is stopped. Then the trace can be read straight from the Ftrace pseudo file system or can be extracted with trace-cmd-extract(1). OPTIONS
The options are the same as trace-cmd-record(1), except that it does not take options specific to recording (-s, -o, -F, -N, and -t). SEE ALSO
trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-stop(1), trace-cmd-extract(1), trace-cmd-reset(1), trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1) AUTHOR
Written by Steven Rostedt, <rostedt@goodmis.org[1]> RESOURCES
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git COPYING
Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL). NOTES
1. rostedt@goodmis.org mailto:rostedt@goodmis.org 06/11/2014 TRACE-CMD-START(1)
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