shell并行下载数据

版本一：无并行

for i in {1..12}

do

{

echo start `date`

wget ftp://ftp.ncbi.nih.gov/snp/organisms/rice_4530/VCF/vcf_chr_${i}.vcf.gz

echo end `date`

}

done

cat *vcf.gz>rice_4530.vcf.gz

rm vcf_chr*

runtime=673s

版本二：并行

for i in {1..12}

do

{

echo start `date`

wget ftp://ftp.ncbi.nih.gov/snp/organisms/rice_4530/VCF/vcf_chr_${i}.vcf.gz

echo end `date`

} &

done

wait

cat *vcf.gz>rice_4530.vcf.gz

rm vcf_chr*

runtime=191s

并行下载的速度比无并行快3倍左右。