filesystem size example

fs.bash

#!/bin/bash
# GNU stat(1) required!

typeset -a filesystems

disk_space_threshold=85
hsummary=
filesystems=(/ /DB-Backup)

function checkFS {
    typeset fs=
    typeset -i fspct=
    
    for fs; do
        if [[ -e "$fs" ]]; then
            fspct=$(stat -fc "(%a*100)/%b" "$fs") || return 1
            if (( (100 - fspct) > disk_space_threshold )); then
                LC_TIME=C printf '%(%a %b %e %H:%M:%S %Z %Y)T\t** Low Disk Space **\t on %s' -1 "$fs"
            fi
        else
            return 1
        fi
    done
}

if ! checkFS "${filesystems[@]}" >>"$hsummary"; then
    echo "Error in checkFS" >&2
    exit 1
fi