抱歉，这个问题有几个层次，但都涉及打开文件的数量。
对于我们正在开发的应用程序，我在应用程序日志中收到“打开的文件过多”消息。有人建议我：
- 查找当前正在使用的打开文件数、系统范围和每个用户
- 找出系统和用户打开文件的限制是多少。
我跑了ulimit -n，它返回了 1024。我还查看了 /etc/limits.conf，该文件中没有任何特别之处。/etc/sysctl.conf 也没有被修改。我将在下面列出文件的内容。我也跑了lsof | wc -l，它返回了 5000+ 行（如果我使用正确的话）。
所以，我的主要问题是：
- 如何找到每个用户允许打开的文件数？软限制是在 /etc/limits.conf 中找到/定义的 nofile 设置吗？因为我没有接触 /etc/limits.conf，所以默认是什么？
- 如何找到系统范围内允许打开的文件数？这是limits.conf中的硬限制吗？如果未修改limits.conf，默认数字是多少？
- ulimit 为打开的文件返回的数字是多少？它说 1024 但是当我运行 lsof 并计算行数时，它超过了 5000+，所以我没有点击。是否还有其他我应该运行的 cmds 或要查看的文件来获得这些限制？在此先感谢您的帮助。
limits.conf 的内容
# /etc/security/limits.conf
#
#Each line describes a limit for a user in the form:
#
#<domain> <type> <item> <value>
#
#Where:
#<domain> can be:
# - an user name
# - a group name, with @group syntax
# - the wildcard *, for default entry
# - the wildcard %, can be also used with %group syntax,
# for maxlogin limit
#
#<type> can have the two values:
# - "soft" for enforcing the soft limits
# - "hard" for enforcing hard limits
#
#<item> can be one of the following:
# - core - limits the core file size (KB)
# - data - max data size (KB)
# - fsize - maximum filesize (KB)
# - memlock - max locked-in-memory address space (KB)
# - nofile - max number of open files
# - rss - max resident set size (KB)
# - stack - max stack size (KB)
# - cpu - max CPU time (MIN)
# - nproc - max number of processes
# - as - address space limit (KB)
# - maxlogins - max number of logins for this user
# - maxsyslogins - max number of logins on the system
# - priority - the priority to run user process with
# - locks - max number of file locks the user can hold
# - sigpending - max number of pending signals
# - msgqueue - max memory used by POSIX message queues (bytes)
# - nice - max nice priority allowed to raise to values: [-20, 19]
# - rtprio - max realtime priority
#
#<domain> <type> <item> <value>
#
#* soft core 0
#* hard rss 10000
#@student hard nproc 20
#@faculty soft nproc 20
#@faculty hard nproc 50
#ftp hard nproc 0
#@student - maxlogins 4
# End of file
sysctl.conf 的内容
# Controls IP packet forwarding
net.ipv4.ip_forward = 0
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
# Controls whether core dumps will append the PID to the core filename
# Useful for debugging multi-threaded applications
kernel.core_uses_pid = 1
# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1
# Controls the maximum size of a message, in bytes
kernel.msgmnb = 65536
# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536
# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
# the interval between the last data packet sent and the first keepalive probe
net.ipv4.tcp_keepalive_time = 600
# the interval between subsequential keepalive probes
net.ipv4.tcp_keepalive_intvl = 60
# the interval between the last data packet sent and the first keepalive probe
net.ipv4.tcp_keepalive_time = 600
# the interval between subsequential keepalive probes
net.ipv4.tcp_keepalive_intvl = 60
# the number of unacknowledged probes to send before considering the connection dead and notifying the application layer
net.ipv4.tcp_keepalive_probes = 10
# the number of unacknowledged probes to send before considering the connection dead and notifying the application layer
net.ipv4.tcp_keepalive_probes = 10
# try as hard as possible not to swap, as safely as possible
vm.swappiness = 1
fs.aio-max-nr = 1048576
#fs.file-max = 4096