awk -v dsrmx=25 -f ./checkSRDry.awk --usage

################################################################################
#
#  --Module---------------------------------------------------------------------
#
#                            checkSRDry.awk
#
#    Prints warnings when the source-receiver distances exceed dsrmx.
#
#  --Usage----------------------------------------------------------------------
#
#    awk [optionalArgs] -f ./checkSRDry.awk file > file_error_log
#
#  --Optional Arguments---------------------------------------------------------
#
#    -v dsrmx=dist
#      Source-receiver distance to check.
#
#    file
#      Input ray path file.
#
#    file_error_log
#      Output file containing warnings.
#
#    -h, --help, -u, --usage, -e, --examples
#      Prints a usage message to STDOUT and exits.
#
#  --Operations-----------------------------------------------------------------
#
#    usage()
#    help(Version)
#
#  --Examples-------------------------------------------------------------------
#
#    awk -v dsrmx=65 -f ./checkSRDry.awk file > file_error_log
#    awk -f ./checkSRDry.awk -h
#
#  --History--------------------------------------------------------------------
#
#    V01 - DEC 2009 - Christopher Dimech
#          Initial release.
#    V02 - JAN 2010 - Christopher Dimech
#          Included command line arguments.
#
################################################################################

#  abs: Returns the absolute value of val

function abs(val) {

  return val > 0 ? val  \
                 : -val

}

################################################################################

#  usage: Description of this awk script

function usage() {

  print ""
  print "--Usage---------------------------------------------------------------"
  print ""
  print "  awk [optionalArgs ] ./checkSRDry.awk file > file_error_log"
  print "  awk -f ./checkSRDry.awk -h"
  print ""
  print "--Optional Arguments--------------------------------------------------"
  print ""
  print "  -v dsrmx=dist     Source to receiver distance to check."
  print "  fin.ry            Input ray path file."
  print "  fout.chk          Output file containing warnings."
  print "  -h, --help, -u, --usage, -e, --examples"
  print "                    Prints a usage message."
  print ""
  print "----------------------------------------------------------------------"
  print ""

}

################################################################################

#  examples:

function examples() {

  print ""
  print "--Examples----------------------------------------------------------"
  print ""
  print "  awk -f ./checkSRDry.awk file > file_error_log"
  print "  awk -f ./checkSRDry.awk -h"
  print ""
  print "--------------------------------------------------------------------"
  print ""
}

################################################################################

#  help: Description of this awk script

function help() {

  print ""
  print "--Module--------------------------------------------------------------"
  print ""
  print "                            checkRays.awk"
  print ""
  print "  Prints warning when source-receiver distances exceed dsrmx"
  print ""
  print "--Usage---------------------------------------------------------------"
  print ""
  print "  awk [optionalArgs] -f ./checkSRDry.awk file > file_error_log"
  print ""
  print "--Optional Arguments--------------------------------------------------"
  print ""
  print "  -v dsrmx=value"
  print "    Source to receiver distance to check"
  print ""
  print "  file"
  print "    Input ray path file."
  print ""
  print "  file_error_log"
  print "    Output file containing warnings."
  print ""
  print "  -h, --help, -u, --usage, -e, --examples"
  print "    Prints a usage message."
  print ""
  print "--Examples-------------------------------------------------------------"
  print ""
  print "  awk -v dsrmx=65 -f ./checkSRDry.awk file > file_error_log"
  print ""
  print "----------------------------------------------------------------------"
  print ""

}

################################################################################

BEGIN {

  c = ARGV[ARGC-1]
  print c

  if ((c == "-u") || (c == "--usage")) {
    usage()
    exit 1
  }

  if ((c == "-e") || (c == "--examples")) {
    examples()
    exit 1
  }

  if ((c == "-h") || (c == "--help")) {
    help()
    exit 1
  }

  if ( !dsrmx ) {
    usage()
    print ""
    print "--Error-------------------------------------------------------------"
    print ""
    print "  Source to receiver distance not set.                     Mandatory"
    print "  Set source to receiver distance using -v dsrmx=dist"
    print ""
    print "--------------------------------------------------------------------"
    print ""
    exit 1
  }

  RS = ">"                                             # Change record separator

  ARGV[ARGC++] = ARGV[ARGC-1]                                  # Read file twice

}

# Error header

NR == 1 {
  print ""
  print "--Warnings------------------------------------------------------------"
  print ""
  print "  Source to receiver distance exceeding",dsrmx,"Mm"
  print ""
  print "----------------------------------------------------------------------"
  print ""
}

# --Read file: First time round-------------------------------------------------

FNR == NR {                                              # Set number of records
  ++i
  next
}

# --Read file: Second time round------------------------------------------------

NF > 2 {
  srdist = abs( $1 - $(NF-2) )
  if (srdist > dsrmx) {                                            # Print error
    print "WARNING: FNR="FNR", dist("$1","$(NF-2)")="srdist
  }
}

END {
#  if (c !~ /(-u|--usage|-e|--examples|-h|--help)/) {
#  print c
#  print ""
#  print "--End of checkTrvtdat.awk---------------------------------------------"
#  print ""
#  }
}

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