getdtablesize(3C)

getdtablesize -- get file descriptor table size

Synopsis

   #include <unistd.h>
   
   int getdtablesize(void);

Description

Each process has a descriptor table, whose entries are numbered with small integers starting at 0. The call getdtablesize returns the current maximum size of this table.

It is equivalent to a call to the getrlimit system call with resource set to RLIMIT_NOFILE.

Return value

The getdtablesize function returns the current soft limit as if obtained from a call to getrlimit with the RLIMIT_NOFILE resource set.

Usage

There is no direct relationship between the value returned by getdtablesize and OPEN_MAX defined in limits.h.

References

close(2), dup(2), getrlimit(2), open(2), select(3C), setrlimit(2)

Standards conformance

This routine conforms to X/Open System Interfaces and Headers, Issue 4, Version 2.