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Full Discussion: Just need some guidance on this nawk
Top Forums UNIX for Dummies Questions & Answers Just need some guidance on this nawk Post 302827485 by newbie_01 on Friday 28th of June 2013 09:04:42 PM
Old 06-28-2013
Just need some guidance on this nawk
Hi,

I am trying to debug some KSH script and it has the nawk portion below. I just want to confirm whether I understand what it does correctly.

Example usage of the nawk line is run as below:

Code:
 
nawk '/^#/ {next}
$1~/^'testp.cfg'$|^'testp.cfg'\.testdb\.com\.ph$/ {
   c=0
   while (getline) {
     gsub (" ","")
     s=tolower($0)
     if (s~/host=/) {
        sub("^.*host=","",s)
        sub("\\\).*","",s)
        print s
        exit
     }
     c++
     if (c>20) {exit}
   }
}' $TNSNAMES

$TNSNAMES is a tnsnames.ora file, excerpts of some of its lines as below:

Code:
 
testd.testdb.com.ph = 
  (DESCRIPTION = 
        (ADDRESS = 
          (COMMUNITY = tcpip.world)
          (PROTOCOL = TCP)
          (Host = testd.testdb.com.ph)
          (Port = 25036)
        )
      (CONNECT_DATA = 
        (SID = testd)
           (GLOBAL_NAME = testd.testdb.com.ph)
      )
  )
testp.cfg = 
  (DESCRIPTION = 
        (ADDRESS = 
          (COMMUNITY = tcpip.world)
          (PROTOCOL = TCP)
          (Host = testp1)
          (Port = 5000)
        )
      (CONNECT_DATA = 
        (SID = testp)
           (GLOBAL_NAME = testp.cfg)
      )
  )

From what I understand, the nawk excludes all lines that begins with a # and if it finds a line that begins with testp.cfg or testp.cfg.testdb.com.ph, and starting from that line, it reads a line, strips the spaces, and convert it to lower case. Now I don't understand what this section of the nawk does?


Code:
     if (s~/host=/) {
        sub("^.*host=","",s)
        sub("\\\).*","",s)
        print s
        exit
     }
     c++
     if (c>20) {exit}


Does the first sub strips all spaces before the host= string? But what does the second sub do? Remove everything from the first dot (.)?

Is the c variable means it will only process 20 lines from when it find the testp.cfg or testp.cfg.testdb.com.ph string?

Any feedback much appreciated. Thanks in advance.
 

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LEARN ABOUT DEBIAN

bbcombotest

BBCOMBOTEST(1)						      General Commands Manual						    BBCOMBOTEST(1)

NAME

       bbcombotest - Xymon combination test tool

SYNOPSIS

       bbcombotest --help
       bbcombotest --version
       bbcombotest [--debug] [--quiet]

DESCRIPTION

       bbcombotest is a Xymon extension script that runs on the BBDISPLAY server.  It combines the results of one or more of the normal Xymon test
       results into a combined test result, using standard arithmetic og logical operators.

       The resulting tests are sent to the Xymon display server as any normal test - so all of the standard Xymon functions  (history,	statistics
       etc.) are available for the combined tests.

       The  tool  was born from the need to monitor systems with built-in redundancy and automatic failover - e.g. load-balanced web servers.  But
       other uses are possible.

OPTIONS

       --quiet
	      Normally, the test status sent by bbcombotest includes information about the underlying test results used to determine  the  current
	      value of the combined test. "--quiet" eliminates this information from the test status page.

       --debug
	      Provide debugging output for use in troubleshooting problems with bbcombotest.

       --no-update
	      Dont send any status messages - instead, the result of the combotests is simply dumped to stdout. Useful for debugging.

FILES

       $BBHOME/etc/bbcombotest.cfg
	      Configuration file for bbcombotest, where the combined tests are defined

       $BBHOME/etc/hobbitlaunch.cfg
	      Configuration file controlling when bbcombotest is run.

SEE ALSO

       bbcombotest.cfg(5), bb-hosts(5), hobbitserver.cfg(5), hobbitlaunch.cfg(5)

Xymon							    Version 4.2.3:  4 Feb 2009						    BBCOMBOTEST(1)
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