#! /bin/bash
# shell script to extract the et column from a hydro.out 
# format file, divide it out into single year segments,
# wrap it into a 8 line UNSAT-H format, placing it into
# separate files for each year with the year + 1900 in
# the file name for all the years in the hydro.out format 
# file.

# find maximum year value in file and set to variable
maxyears=`dm "if N>1 then INPUT else SKIP" <$1 | dm x3 | stats max`

# set first year 
let year=0
while [ "$year" != "$maxyears" ]
do
    let year=year+1

    # shift into 1900 year range
    let outyear=year+1900

    # first line, skips lines without full columns
    # second line, selects desired year
    # third line, pulls eight values unto one line
    # '$!N' stops getting lines at the last line
    # fourth line, adds comma to end of each line

    dm "if N>1 then INPUT else SKIP" <$1 | \
    dm "if x3=$year then x4/10 else SKIP" | \
    sed -e '$!N' -e '$!N' -e '$!N' -e '$!N' -e '$!N' -e '$!N' -e '$!N' -e 's/\n/,/g' | \
    sed 's/$/,/' > "pet$outyear.pen"

    echo "created pet$outyear.pen evapotranspiration file"
done