Shell Programming and Scripting

WR030B      266.48 Grad      0
WR050B      271.46 Grad      0
WR120B      268.11 Grad      0
WV030B        2.51 m/s       0
WV050B        3.47 m/s       0
WV120B        4.82 m/s       0
TLUFT02B      7.82 °C       0
TLUFT12B      6.87 °C       0
NSCHLB        0.00 mm        0

#!/bin/bash
a=$(date --date '1 month ago' +%m)
e=$(date +%m)
y=$(date +%Y)
home=$HOME/Desktop/Messdaten/METE
cd $home
fpat=$(ls `eval echo $y{$a,$e}*` | tail -n 1584) ## 1584 Dateien entspr. 11 Tagen
for i in $fpat
do
      if test -f "$i"
      then
         Dy=${i:2:2} Dm=${i:4:2} Dd=${i:6:2}
        UZh=${i:8:2} UZm=${i:10:2}
        res=$(awk '{A[$1]=$2}END{print A["WV120B"], A["WR120B"], A["NSCHLB"], A["TLUFT12B"], A["TLUFT02B"]}' OFS='\t' "$i")
       T120=$(awk '{B[$1]=$2}END{print B["TLUFT12B"]}' "$i")
        T20=$(awk '{C[$1]=$2}END{print C["TLUFT02B"]}' "$i")
        printf "%s/%s/%s-%s:%s\t%s\t%s\n" $Dm $Dd $Dy $UZh $UZm "$res" "$T20-$T120"
      else
        DAT=$(date +%Y%m%d)
        printf "$DAT - Datei $i nicht vorhanden" >> "$home/../Logfiles/Log_$(date +%Y%m%d).log"
    fi
done

$ a=10; b=8
$ printf "%d\n" $(echo "$a-$b" | bc)
2

$ a=10; b=8
$ printf "%f\n" $(echo "$a-$b" | bc)
2.000000

$ a=10; b=8
$ printf "%s\n" "$a-$b"
10-8

$ a=10; b=8
$ printf "%s\n" $((a-b))
2

printf "%s/%s/%s-%s:%s\t%s\t%f\n" $Dm $Dd $Dy $UZh $UZm "$res" "$T20-$T120"

line 17: printf: 17.10-17.02: invalid number

$((T20-T120))

$(echo "$T20-$T120" | bc)