Bash function to get the number of pages in pdf files

pdfpages.sh

pdfpages () {
    if [[ $# -ne 1 ]]; then
        echo "$FUNCNAME: expected one argument, got $#"
        return 1
    fi
    local filename="$1"
    while read line; do
        if [[ "$line" =~ ^Pages:" "+([0-9]+)$ ]]; then
            echo "${BASH_REMATCH[1]}"
            return 0
        fi
    done < <(pdfinfo -- "$filename")
    echo "$FUNCNAME: failed to read number of pages using command pdfinfo"
    return 1
}