NAME

     getval  - get values from USP line or trace headers

SYNOPSIS

     getval [ -Nntap ] [ -Ootap ] [  -Llnkey  ]  [  -Ttrkey  ]  [
     -nsnstr ] [ -nenetr ] [ -rsnrst ] [ -renred ] [ -? ]

DESCRIPTION

     getval retrieves values from the line header  or  the  trace
     headers  (or  both) of a USP dataset and writes these values
     to stdout. If desired, this output data  may  be  commented.
     Otherwise  it  is output in a "raw" format. This program may
     be embedded in script  files  to  extract  values  from  the
     headers and either calculate new values required by the pro-
     cessing flow  or  make  decisions  based  on  these  values.
     Another  useful  aspect  of  getval is the retrieval of info
     pertaining to 3-D data into a file which may be then be used
     for graphing this information.

     getval gets both its data and its  parameters  from  command
     line  arguments.   These arguments specify the input, header
     keys, the start and end traces and records.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing -N unless the input is from a pipe in which case
          the -N entry must be omitted.  This input  file  should
          include the complete path name if the file resides in a
          different directory.  Example -N/b/vsp/dummy tells  the
          program to look for file 'dummy' in directory '/b/vsp'.

     -O otap
          Enter the output file name immediately after typing  -O
          unless the output is to gto stdout in which case the -O
          entry may be omitted.

     -L lnkey
          Enter the line header key for the  value  desired  (see
          scan documentation for the full list of keys)

     -T trkey
          Enter the trace header key for the value  desired  (see
          scan  documentation  for the full list of keys).  Note:
          multiple -L and -T values may be specified for each run
          of getval

     -ns nstr
          Enter the start trace number.  The default is the first
          trace of the record.


     -ne netr
          Enter the end trace number. The  default  is  the  last
          trace of the record.

     -rs nrst
          Enter start record number.  Default value is the  first
          record.

     -re nred
          Enter end record number.  Default value is last record.

     -V   The command line argument '-V' may be specified to  add
          comments   to   the  output  denoting  each  column  of
          requested data.

     -?   Enter the command line  argument  '-?'  to  get  online
          help.   The program terminates after the help screen is
          printed.

  Example of Use in a Script
     #!  /bin/sh

     #  This is a script to test program getval

     #  The aim of this is to be able to extract line or trace

     #  header values from input data and use these values

     #  inside a script

     #  The test data set is a single shot record called rec122

     #  Example 1:  extract sample interval;

     #              calculate nyquist frequency

     nsi=`getval -Nrec122 -LSmpInt`

     fnyq=`expr 500 / $nsi`

     echo "Sample Interval= "$nsi"  Nyquist Frequency= "$fnyq

BUGS

     Absolutely none, of course.

SEE ALSO

     scan

AUTHOR

     P. R. Gutowski, OBU/ATTC, pgutowski@amoco.com
     Joe M. Wade, ATTC, jwade@amoco.com

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.