lvis@lvis-dell-xps:~/bin$ more compress_all_mjd.sh 
#!/bin/bash
 
echo "Usage $0 <input dir> <output dir>"
 
M_INPUTDIR=$(echo $1 | sed '/\/$/! s|$|/|')  # add a slash if necessary
M_OUTPUTDIR=$(echo $2 | sed '/\/$/! s|$|/|') # found online
 
echo Input: $M_INPUTDIR
echo Output: $M_OUTPUTDIR
 
cd $M_INPUTDIR
for f in *; do
    if [ -d "$f" ]; then
        M_BASENAME=$(basename $f)
        re='^[0-9]+$'  # check if this is a just a number (day mjd) (found online)
        if [[ $M_BASENAME =~ $re ]] ; then
           M_TARFILE="${M_OUTPUTDIR}${M_BASENAME=}_raw_data.tar.gz"
           echo "Run on $f which is $M_BASENAME"
           time tar cf - $f | pigz > $M_TARFILE
        fi
    fi
done