Rename shapefile field names from uppercase to lowercase using OGR

gistfile1.sh

declare -a fields=("ROADID" "SOURCEID" "NOTES" "ONME" "RTENME" "NTLCLASS" "FCLASS" "NUMLANES" "SRFTPE" "SRFCOND" "SRFPREP" "ISSEASONAL" "CURNTPRAC" "GNRALSPEED" "GDWTHRPRAC" "BDWTHRPRAC" "SHAPE_LENG" "ADM0_CODE" "ADM0_NAME" "CONTINENT" "REGION")

shp="was_trs_roads_wfp"

for f in "${fields[@]}"
do
    lf=$(echo $f | awk '{print tolower($0)}')
    echo $lf
    ogrinfo $shp.shp -sql "ALTER TABLE $shp RENAME COLUMN $f TO $lf"
done