问题描述
这是非常奇怪的wget行为.我使用的是Debian 7.2.
This is a VERY strange wget behavior. I'm on debian 7.2.
wget -r -O - www.blankwebsite.com
永远挂起.我是说挂起，它不是通过互联网搜索的，我可以用strace进行验证.如果我这样做:
hangs forever. And I mean it hangs, it isn't searching through the internet,I can verify it with a strace.If I do this:
while read R
do
wget -r -O - www.blankwebsite.com
done < smallfile
smallfile包含一行，命令将在几秒钟后退出.
with smallfile containing a single line, the command exits in a few seconds.
我也尝试过
wget -r -O - localhost/test.html
和一个空的test.html文件，结果相同.对我来说，这听起来像是个错误.
一切都很好用-O myfile更改-O -或删除-r.
我使用-O -是因为我将输出传递给grep.
谁能解释一下?你看到类似的东西了吗?
with an empty test.html file, same results. To me, it sounds like a bug.
Everything runs fine changing -O - with -O myfile or removing -r.
I used -O - because I was passing output to grep.
Could anyone explain that? Have you seen anything similar?
推荐答案
当然:
wget -r -O file www.blankwebsite.com
可以，但是BUG是这样的:
works, but the BUG is that:
wget -r -O - www.blankwebsite.com
挂起！
同样的问题是，如果您创建FIFO
The same problem is if you create a FIFO
mkfifo /tmp/myfifo
wget -r -O /tmp/myfifo www.blankwebsite.com
使用-r选项调用
wget时，它将尝试找到读取输出文件的HTML"a href = ..."标记.由于输出文件是FIFO或stdout(例如HYPHEN char'-')，因此无法找到任何标签并等待INPUT.然后，在读取系统调用上，您将永远拥有一个wget进程waintg.
wget, when called with -r option, will try to find HTML "a href=..." tags reading the output file. Since the output file is a FIFO or stdout (ex. HYPHEN char '-') it is not able to find any tag and waits for INPUT. Then you will have a wget process waintg forever on a read system call.
要解决此问题，您可以:1)修补wget来处理这种情况2)修补wget不允许使用"-r -O-"组合...(只需检查"-O"的参数是否为常规文件)3)使用类似的解决方法:
To resolve this you can:1) Patch wget to handle this case2) Patch wget to not allow "-r -O -" combination... (Just check that the argument of '-O' is a regular file)3) Use a workaround like:
TMPFILE=$(mktemp /tmp/wget.XXXXXX)
wget -r -O $TMPFILE www.blankwebsite.com
grep STRING $TMPFILE
rm $TMPFILE
这篇关于wget与-r和-O一起挂起-的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！