下面是代码：(转自CU)

(俺是新手，高手见笑)

用法：./mycurl url

#!/bin/bash

######################################################################################################

#

# Script for curl to support resumable multi-part download.

#

url=$1

exename=`basename $0`

# How many "parts" will the target file be divided into?

declare -i parts=5

read -ep "Please input the target directory: " targetdir

read -ep "Please input the outfile name: " outfile

[ -z "$targetdir" ] && targetdir="./"

cd $targetdir||exit 2

[ -z "$outfile" ] && outfile=`basename $1`

length=`curl -s -I $url|grep Content-Length|sed s/[^0-9]//g`

#length=`curl -s -I $url|grep Content-Length|awk '{print $2}'|sed s/[^0-9]//`

if [ -z "$length" ]; then

echo "cann't get the length of the target file"

exit 1

fi

let "length = $length"

declare -i lsession=$(($length/$parts))

finished="false"

while true;

do

declare -i curr=0

for (( i=1; i<=parts; i=i+1 ))

do

#To get how many bytes have been downloaded

if [ -e $outfile$i ]; then

offset=`ls -l $outfile$i|awk '{print $5}'`

else offset=0

fi

let "offset = $offset"

if [ $i -lt $parts ]; then

if [ $offset -lt $lsession ]; then

curl -r $(($curr+$offset))-$(($curr+$lsession-1)) $url >> $outfile$i &

fi

else

if [ $offset -lt $(($length-$(($lsession*$(($parts-1)))))) ]; then

curl -r $(($curr+$offset))- $url >> $outfile$i &

fi

fi

curr=$(($curr+$lsession))

done

#To judge if all curl threads have terminated.

while true;

do

hasCurl=`ps -A -o ppid,cmd|grep $$|grep -v "$exename"|grep -v "grep"|grep curl`

[ -z "$hasCurl" ] && break

sleep 10

done

finished="true"

for (( i=1; i<=$parts; i=i+1 ))

do

if [ -e $outfile$i ]; then

offset=`ls -l $outfile$i|awk '{print $5}'`

else offset=0

fi

let "offset = $offset"

if [ $i -lt $parts ]; then

if [ $offset -lt $lsession ]; then

finished="false"

break

fi

else

if [ $offset -lt $(($length-$(($lsession*$(($parts-1)))))) ]; then

finished="false"

break

fi

fi

done

if [ "$finished" == "true" ]; then

break

fi

done

echo "All parts have been downloaded. Merging..."

mv --backup=t $outfile"1" $outfile

for (( i=2; i<=$parts; i=i+1))

do

cat $outfile$i >> $outfile

rm $outfile$i

done

echo "Done."