#!/bin/csh -f
* +-======-+ 
*  Copyright (c) 2003-2018 United States Government as represented by 
*  the Admistrator of the National Aeronautics and Space Administration.  
*  All Rights Reserved.
*  
*  THIS OPEN  SOURCE  AGREEMENT  ("AGREEMENT") DEFINES  THE  RIGHTS  OF USE,
*  REPRODUCTION,  DISTRIBUTION,  MODIFICATION AND REDISTRIBUTION OF CERTAIN 
*  COMPUTER SOFTWARE ORIGINALLY RELEASED BY THE UNITED STATES GOVERNMENT AS 
*  REPRESENTED BY THE GOVERNMENT AGENCY LISTED BELOW ("GOVERNMENT AGENCY").  
*  THE UNITED STATES GOVERNMENT, AS REPRESENTED BY GOVERNMENT AGENCY, IS AN 
*  INTENDED  THIRD-PARTY  BENEFICIARY  OF  ALL  SUBSEQUENT DISTRIBUTIONS OR 
*  REDISTRIBUTIONS  OF THE  SUBJECT  SOFTWARE.  ANYONE WHO USES, REPRODUCES, 
*  DISTRIBUTES, MODIFIES  OR REDISTRIBUTES THE SUBJECT SOFTWARE, AS DEFINED 
*  HEREIN, OR ANY PART THEREOF,  IS,  BY THAT ACTION, ACCEPTING IN FULL THE 
*  RESPONSIBILITIES AND OBLIGATIONS CONTAINED IN THIS AGREEMENT.
*  
*  Government Agency: National Aeronautics and Space Administration
*  Government Agency Original Software Designation: GSC-15354-1
*  Government Agency Original Software Title:  GEOS-5 GCM Modeling Software
*  User Registration Requested.  Please Visit http://opensource.gsfc.nasa.gov
*  Government Agency Point of Contact for Original Software:  
*  			Dale Hithon, SRA Assistant, (301) 286-2691
*  
* +-======-+ 

set FILENAME = grads.txt
set TEMPFN = grepfile.txt

# The next five lines are from the original 
# script.  The "extra" searching that follows
# changes the result only if a match is found.
# --------------------------------------------
if( .$2 == . ) then
 cat $1 > ${FILENAME}
else
 cat $1 | grep $2 > ${FILENAME}
endif

# Determine length of input string.
# ---------------------------------
set LENGTH = `echo ${2} | wc -c`

# Many (and maybe all?) ${2}s have a nonprintable
# terminating character. Assume that the input string
# without its last character is sufficient for a match.
# -----------------------------------------------------
set REQUIRED_LENGTH = `expr ${LENGTH} - 1`

# How many instances did the grep find?
# -------------------------------------
set LINES = `cat ${FILENAME} | wc -l`

# Search ${FILENAME} backward line-by-line looking
# for ${2} less its teminating character, but select
# only the case in which no characters preceed the string.
# --------------------------------------------------------
set N = 1
while ( ${N} <= ${LINES} )

 set STRING = `tail -${N} ${FILENAME} | line | awk '{ print $1 }'`
 set LENGTH = `echo ${STRING} | wc -c`
 @ LENGTH  = ${LENGTH} - 1

# If a : is in the string, take only
# those characters that precede it.
# ----------------------------------
 set M = 1
 set COLON_POSITION = -1
 while ( ${M} <= ${LENGTH} )
  set CHAR = `echo ${STRING} | cut -c${M}`
  if ( ${CHAR} == : ) then
   set COLON_POSITION = ${M}
   set M = ${LENGTH}
  endif
  @ M = $M + 1
 end
 if ( ${COLON_POSITION} > 0 ) then
  set LENGTH = `expr ${COLON_POSITION} - 1`
 endif

# If the length of the extracted string matches the 
# length of ${2} less its teminating character, then
# save this line in a temporary text file, and quit.
# --------------------------------------------------
 if ( ${LENGTH} == ${REQUIRED_LENGTH} ) then
  tail -${N} ${FILENAME} | line > ${TEMPFN}
  set N = ${LINES}
 endif

# Increment number of lines to tail 
# ---------------------------------
 @ N = $N + 1
end

# Overwrite $(FILENAME} with the single line of text.
# ---------------------------------------------------
if ( -e ${TEMPFN} ) /bin/mv -f ${TEMPFN} ${FILENAME}

exit