一种shell并发模型

#!/bin/bash

parallel=10

fileArr=(`ls -1 fileid/pre*`)

for ((i=0; i<${#fileArr[*]}; i+=$parallel)); do
    for ((j=$i; j<$i+$parallel; j++)); do
        if (($j<${#fileArr[*]})); then
            python offline_download.pyc -f ${fileArr[$j]} &
        fi
    done

    wait
done