blocks|key|335056|text|对/proc/<pid>/fd/中的条目进行计数。适用于该进程的硬限制和软限制可在/proc/<pid>/limits中找到。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|335057|entityMap^0|1|F|15|I|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

Count the entries in <code>/proc/&lt;pid&gt;/fd/</code>. The hard and soft limits applying to the process can be found in <code>/proc/&lt;pid&gt;/limits</code>.

blocks|key|331588|text|Linux内核提供的获取资源限制的唯一接口是getrlimit()和/proc//limits。getrlimit()只能获取调用进程的资源限制。/proc/pid/limits允许您获取具有相同用户id的任何进程的资源限制，并且在RHEL5.2、RHEL4.7、Ubuntu9.04以及带有2.6.24或更高版本内核的任何发行版上都可用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|331589|如果您需要支持较旧的Linux系统，那么您必须让进程本身调用getrlimit()。当然，要做到这一点，最简单的方法是修改程序或它使用的库。如果您正在运行该程序，则可以使用LD_PRELOAD将您自己的代码加载到该程序中。如果这些都不可能，那么您可以使用gdb附加到进程，并让它在进程内执行调用。你也可以自己做同样的事情，使用ptrace()附加到进程，将调用插入到它的内存中，等等，但是这是非常复杂的，不推荐这样做。|331590|有了适当的权限，其他方法将涉及查看内核内存、加载内核模块或以其他方式修改内核，但我假设这些都是不可能的。|331591|entityMap|0|LINK|mutability|MUTABLE|url|http://www.kernel.org/doc/man-pages/online/pages/man2/getrlimit.2.html|1|http://www.kernel.org/doc/man-pages/online/pages/man5/proc.5.html^0|M|B|Y|D|1C|B|21|6|2A|7|M|B|0|Y|D|1|0|U|B|2E|A|4J|8|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@$9|14|A|15|1|16]|$9|17|A|18|1|19]]|E|$]]|$1|F|3|G|5|6|7|1A|8|@$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1H|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]]|K|$L|$5|M|N|O|E|$P|Q]]|R|$5|M|N|O|E|$P|S]]]]

The only interfaces provided by the Linux kernel to get resource limits are <a href="http://www.kernel.org/doc/man-pages/online/pages/man2/getrlimit.2.html" rel="noreferrer"><code>getrlimit()</code></a> and <a href="http://www.kernel.org/doc/man-pages/online/pages/man5/proc.5.html" rel="noreferrer"><code>/proc/</code>pid<code>/limits</code></a>. <code>getrlimit()</code> can only get resource limits of the calling process. <code>/proc/</code>pid<code>/limits</code> allows you to get the resource limits of any process with the same user id, and is available on RHEL 5.2, RHEL 4.7, Ubuntu 9.04, and any distribution with a 2.6.24 or later kernel.

If you need to support older Linux systems then you will have to get the process itself to call <code>getrlimit()</code>. Of course the easiest way to do that is by modifying the program, or a library that it uses. If you are running the program then you could use <code>LD_PRELOAD</code> to load your own code into the program. If none of those are possible then you could attach to the process with gdb and have it execute the call within the process. You could also do the same thing yourself using <code>ptrace()</code> to attach to the process, insert the call in its memory, etc., however this is very complicated to get right and is not recommended.

With appropriate privileges, the other ways to do this would involve looking through kernel memory, loading a kernel module, or otherwise modifying the kernel, but I am assuming that these are out of the question.

blocks|key|335053|text|您可以尝试编写对给定pid定期调用lsof+-p+{PID}的脚本。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|335054|entityMap^0|H|D|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

You can try to write script which periodically call <code>lsof -p {PID}</code> on given pid.

blocks|key|3305615|text|您要求使用bash/python方法。ulimit将是最好的bash方法(除了手动使用/proc/$pid/fd之类的东西)。对于python，您可以使用资源模块。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3305616|import+resource

print(resource.getrlimit(resource.RLIMIT_NOFILE))|code-block|syntax|javascript|3305617|3305618|+$+python+test.py+(1024,65536)|blockquote|3305619|3305620|3305621|resource.getrlimit对应于C程序中的getrlimit调用。结果表示所请求资源的当前值和最大值。在上面的示例中，电流(软)限制为1024。这些值是目前Linux系统上的典型默认值。|3305622|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/3/library/resource.html#resource.getrlimit^0|17|D|0|0|0|0|0|0|0|I|Q|9|0|I|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|14|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|15|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|16|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|17|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|18|8|@$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|D|@$9|1D|A|1E|1|1F]]|E|$]]|$1|S|3|-4|5|6|7|1G|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]]]

You asked for bash/python methods. ulimit would be the best bash approach (short of munging through <code>/proc/$pid/fd</code> and the like by hand). For python, you could use the resource module.

<pre><code>import resource

print(resource.getrlimit(resource.RLIMIT_NOFILE))
</code></pre>

<blockquote>
<pre><code>$ python test.py

(1024, 65536)
</code></pre>
</blockquote>

<a href="https://docs.python.org/3/library/resource.html#resource.getrlimit" rel="nofollow noreferrer"><code>resource.getrlimit</code></a> corresponds to the <code>getrlimit</code> call in a C program. The results represent the current and maximum values for the requested resource. In the above example, the current (soft) limit is 1024. The values are typical defaults on Linux systems these days.

blocks|key|330123|text|要查看使用进程的前20个文件句柄：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|330124|for+x+in+`ps+-eF%7C+awk+'{+print+$2+}'`;do+echo+`ls+/proc/$x/fd+2>+/dev/null+%7C+wc+-l`+$x+`cat+/proc/$x/cmdline+2>+/dev/null`;done+%7C+sort+-n+-r+%7C+head+-n+20|code-block|syntax|javascript|330125|输出的格式为进程的文件句柄count，pid，cmndline|330126|输出示例|330127|701+1216+/sbin/rsyslogd-n-c5
169+11835+postgres:+spaceuser+spaceschema+[local]+idle
164+13621+postgres:+spaceuser+spaceschema+[local]+idle
161+13622+postgres:+spaceuser+spaceschema+[local]+idle
161+13618+postgres:+spaceuser+spaceschema+[local]+idle|330128|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

to see the top 20 file handle using processes:

<pre><code>for x in `ps -eF| awk '{ print $2 }'`;do echo `ls /proc/$x/fd 2&gt; /dev/null | wc -l` $x `cat /proc/$x/cmdline 2&gt; /dev/null`;done | sort -n -r | head -n 20
</code></pre>

the output is in the format file handle count, pid, cmndline for process

example output

<pre><code>701 1216 /sbin/rsyslogd-n-c5
169 11835 postgres: spaceuser spaceschema [local] idle
164 13621 postgres: spaceuser spaceschema [local] idle
161 13622 postgres: spaceuser spaceschema [local] idle
161 13618 postgres: spaceuser spaceschema [local] idle
</code></pre>

blocks|key|3093056|text|使用优秀的psutil包的Python包装器：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3093057|import+psutil

for+p+in+psutil.process_iter(attrs=['pid',+'name',+'username',+'num_fds']):
++++try:
++++++++soft,+hard+=+p.rlimit(psutil.RLIMIT_NOFILE)
++++++++cur+=+p.info['num_fds']
++++++++usage+=+int(cur+/+soft+*+100)
++++++++print('{:>2d}%25+{}/{}/{}'.format(
++++++++++++usage,
++++++++++++p.info['pid'],
++++++++++++p.info['username'],
++++++++++++p.info['name'],
++++++++++++))
++++except+psutil.NoSuchProcess:
++++++++pass|code-block|syntax|javascript|3093058|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Python wrapper using the excellent psutil package:

<pre><code>import psutil

for p in psutil.process_iter(attrs=['pid', 'name', 'username', 'num_fds']):
 try:
 soft, hard = p.rlimit(psutil.RLIMIT_NOFILE)
 cur = p.info['num_fds']
 usage = int(cur / soft * 100)
 print('{:&gt;2d}% {}/{}/{}'.format(
 usage,
 p.info['pid'],
 p.info['username'],
 p.info['name'],
 ))
 except psutil.NoSuchProcess:
 pass
</code></pre>

blocks|key|3305698|text|在CentOS+6及更低版本(任何使用GCC+3的操作系统)中，您可能会发现调整内核限制并不能解决问题。这是因为有一个FD_SETSIZE值是在编译时设置的，由GCC使用。为此，您需要增加该值，然后重新编译该过程。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3305699|此外，如果您使用的是known+issues+in+libpthread库，您可能会发现由于该库而泄漏了文件描述符。这个调用被集成到了GCC+4/+CentOS7+/RHEL7中的GCC中，这似乎已经修复了线程问题。|3305700|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/7976388/increasing-limit-of-fd-setsize-and-select|1|https://www.gnu.org/software/hurd/libpthread.html^0|1N|A|0|0|A|Q|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@$A|U|B|V|1|W]]|C|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]]]

In CentOS 6 and below (anything using GCC 3), you may find that adjusting the kernel limits does not resolve the issue. This is because there is a <a href="https://stackoverflow.com/questions/7976388/increasing-limit-of-fd-setsize-and-select">FD_SETSIZE</a> value that is set at compile time in use by GCC. For this, you will need to increase the value and then re-compile the process.

Also, you may find that you are leaking file descriptors due to <a href="https://www.gnu.org/software/hurd/libpthread.html" rel="nofollow noreferrer">known issues in libpthread</a> if you are using that library. This call was integrated into GCC in GCC 4 / CentOS7 / RHEL 7 and this seems to have fixed the threading issues.

I recently had a Linux process which “leaked” file descriptors: It opened them and didn't properly close some of them.
If I had monitored this, I could tell – in advance – that the process was reaching its limit.
Is there a nice, Bash or Python way to check the FD usage ratio for a given process in a Ubuntu Linux system?
EDIT:
I now know how to check how many open file descriptors are there; I only need to know how many file descriptors are allowed for a process. Some systems (like Amazon EC2) don't have the <code>/proc/pid/limits</code> file.

Check the open FD limit for a given process in Linux

Python

CentOS

Ubuntu

Linux

我最近遇到了一个Linux进程，它“泄漏”了文件描述符:它打开了文件描述符，但没有正确地关闭其中一些描述符。如果我监测到了这一点，我可以提前知道这个过程正在达到它的极限。在Ubuntu Linux系统中，有没有一种很好的、Bash或Python的方法来检查给定进程的FD使用率？编辑：我现在知道如何检查有多少打开的文件描述符；我只需要知道一个进程允许多少个文件描述符。有些系统(如亚马逊EC2)没有/

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