Shell Programming and Scripting

FSvar=","      ### set FS variable for field separator
eoc2csv ()
{
   awk -v FSvar=$FSvar '
     {FS=IFS=OFS=FSvar}
     {
     SI=substr($0,1,13)
     NA=substr($0,14,30)
     AD=substr($0,44,92)
     GR=substr($0,136,9)
     CC=substr($0,164,6)
     UA=substr($0,170,4)
     DT=substr($0,180,3)
     ED=substr($0,183,8)
     DS=substr($0,251,8)
     JN=substr($0,271,10)
     SQ=substr($0,293,8)
     ET=substr($0,397,1)
     GT=substr($0,401,2)
     SD=substr($0,451,10)

     print SI,NA,AD,GR,CC,UA,DT,ED,DS,JN,SQ,ET,GT,SD
   }'
   return
}

function setFieldsByWidth(   i,n,FWS,start,copyd0) {
  # Licensed under GPL Peter S Tillier, 2003
  # NB corrupts $0
  copyd0 = $0                             # make copy of $0 to work on
  if (length(FIELDWIDTHS) == 0) {
    print "You need to set the width of the fields that you require" > "/dev/stderr"
    print "in the variable FIELDWIDTHS (NB: Upper case!)" > "/dev/stderr"
    exit(1)
  }

  if (!match(FIELDWIDTHS,/^[0-9 ]+$/)) {
    print "The variable FIELDWIDTHS must contain digits, separated" > "/dev/stderr"
    print "by spaces." > "/dev/stderr"
    exit(1)
  }

  n = split(FIELDWIDTHS,FWS)

  if (n == 1) {
    print "Warning: FIELDWIDTHS contains only one field width." > "/dev/stderr"
    print "Attempting to continue." > "/dev/stderr"
  }

  start = 1
  for (i=1; i <= n; i++) {
    $i = substr(copyd0,start,FWS[i])
    start = start + FWS[i]
  }
}

#Note that the "/dev/stderr" entries in some lines have wrapped.

#I then call setFieldsByWidth() in my main awk code as follows:

BEGIN {
  #FIELDWIDTHS="7 6 5 4 3 2 1" # for example
  FIELDWIDTHS="1 3 8 8 5 9 1 9" # for example
  OFS="|"
}
!/^[  ]*$/ {
  saveDollarZero = $0 # if you want it later
  setFieldsByWidth()
  # now we can manipulate $0, NF and $1 .. $NF as we wish
  print $0 OFS
  next
}

if (recordType == recordType1) ? setFieldsByWidth(FIELDWIDTH1) : setFieldsByWidth(FIELDWIDTH2)

function setFieldsByWidth(FIELDWIDTH,       i,n,FWS,start,copyd0)