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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

pymcabatch

pymcabatch(1)						 PyMca X-Ray Fluorescence Toolkit					     pymcabatch(1)

NAME

       pymcabatch - Batch fitting of X-ray Fluorescence Spectra

SYNOPSIS

       pymcabatch [OPTIONS] [FILES]

DESCRIPTION

       Loops  over a series of input files to which the same fitting parameters can be applied. The setup of the fit configuration is usually made
       via the main PyMca application.

       The program stores the fitted parameters inside the IMAGES directory created in the user specfified output  directory.  The  pymcapostbatch
       tool can perform further analysis via correlation tools.

       The user can also request an HTML report. This is much slower but can be convenient to browse the results with a Web browser.

       This tool is also accessible via the Tools menu of the main PyMca window application.

EXAMPLES

       pymcabatch
	   Open a dialog to select input files, fit configuration, output
	   directory and output parameters.

       pymcabatch --cfg=fitconfig.cfg --outdir=/tmp/ *.mca
	   Fit all the .mca files in current directory using the specified
	   confifuration file fitconfig.cfg and stores the output in /tmp

       pymcabatch --cfg=fitconfig.cfg --outdir=/tmp/ --listfile=inputfiles
	   Same as above but taken the files from the inputfiles file. This file
	   is just a text file with one file path in each line.

CAVEATS

       This  tool,  when  used	in command line mode, could run fully Qt independent because in that case it uses Qt just for showing the progress
       bar.

SEE ALSO

       pymca, pymcapostbatch

ESRF
								    March 2012							     pymcabatch(1)
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