On Unix/Linux systems, there is a limit set in the kernel on how many open file descriptors are allowed on the system. This may be compiled in, or it may be tunable on the fly. In Linux, the value of this parameter can be read from and written to the proc filesystem.
# cat /proc/sys/fs/file-max
52427
On this system the maximum number of open file descriptors is set to 52,427. It is unlikely that we would run out, but if we wanted to change it, you can run the command below:
# echo “104854” > /proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
104854