UNIX for Dummies Questions & Answers

-0.000000000000000000000000000020000000000000000000000000000000 t_-0.20000E+03.dat
+0.000000000000000000000000000000000000000000000000000000000000 t_ 0.0000_.dat
+0.000000000000000000000000000000000010000000000000000000000000 t_ 0.10000E-03.dat
+0.000000000000000000000000000000000020000000000000000000000000 t_ 0.20000E-03.dat
+0.000000000000000000000000000000000200000000000000000000000000 t_ 0.20000E-02.dat
+0.000000000000000000000000000000000210000000000000000000000000 t_ 0.21000E-02.dat
+0.000000000000000000000000000000000220000000000000000000000000 t_ 0.22000E-02.dat
+0.000000000000000000000000000000002000000000000000000000000000 t_ 0.20000E-01.dat
+0.000000000000000000000000000000002000000000000000000000000000 t_ 2.00000E-02.dat
+0.000000000000000000000000000000002000000000000000000000000000 t_ 20.00000E-03.dat
+0.000000000000000000000000000000020000000000000000000000000000 t_ 0.20000E-00.dat
+0.000000000000000000000000000000200000000000000000000000000000 t_ 0.20000E+01.dat
+0.000000000000000000000000000002000000000000000000000000000000 t_ 0.20000E+02.dat
+0.000000000000000000000000000020000000000000000000000000000000 t_ 0.20000E+03.dat

#!/bin/bash

OLDIFS="$IFS"
IFS=" _tdatE. "

N=0

for FILE in t_*.dat
do
        # Convert exponential notation into fixed point.
        # We do this by removing zeroes from the front
        # to increase the exponent, adding zeroes to the front
        # to decrease the exponent, and padding zeroes onto the
        # end to a fixed length.  This will produce a number
        # that can be sorted.

        set -- $FILE
        set -- $*

        SIGN="+"

        if [ "${1:0:1}" = "-" ]
        then
                SIGN="-"
                set -- ${1:1} ${2} ${3}
        fi

        if [ "${1:0:1}" = "+" ]
        then
                set -- ${1:1} $2 $3
        fi

        EXP=${3}
        VAL="000000000000000000000000000000${1}${2}"

        LEN="${#1}"
        while [ "$LEN" -gt 1 ]
        do
                VAL="${VAL:1}"
                let LEN=LEN-1
        done


        [ -z "$EXP" ] && EXP="0"

        # Strip leading zeroes from exponent
        while [ "${EXP:0:2}" = "-0" ] ; do EXP=${EXP/-0/-} ; done
        while [ "${EXP:0:2}" = "+0" ] ; do EXP=${EXP/+0/+} ; done
        [ "$EXP" = "-" -o "$EXP" = "+" ] && EXP=0

        # Strip zeroes off the front of the number for positive exponent
        while [ "$EXP" -gt 0 ]
        do
                VAL="${VAL:1}"
                let EXP=EXP-1
        done

        # Add zeroes to the front of the number for negative exponent
        while [ $EXP -lt 0 ]
        do
                VAL="0${VAL}"
                let EXP=EXP+1
        done

        while [ "${#VAL}" -lt 60 ] ; do VAL="${VAL}0" ; done

        printf "%s0.%s\t%s\n" ${SIGN} "${VAL}" "${FILE}"
done | sort -n | while IFS="$OLDIFS" read ORDER FILENAME
do
        NAME=$(printf "t%05d.dat" $N)
        let N=N+1
        echo mv "$FILENAME" "$NAME"
done

$ ./float.sh

mv t_-0.20000E+03.dat t00000.dat
mv t_ 0.0000_.dat t00001.dat
mv t_ 0.10000E-03.dat t00002.dat
mv t_ 0.20000E-03.dat t00003.dat
mv t_ 0.20000E-02.dat t00004.dat
mv t_ 0.21000E-02.dat t00005.dat
mv t_ 0.22000E-02.dat t00006.dat
mv t_ 0.20000E-01.dat t00007.dat
mv t_ 2.00000E-02.dat t00008.dat
mv t_ 20.00000E-03.dat t00009.dat
mv t_ 0.20000E-00.dat t00010.dat
mv t_ 0.20000E+01.dat t00011.dat
mv t_ 0.20000E+02.dat t00012.dat
mv t_ 0.20000E+03.dat t00013.dat

$