getdtablesize(2)

DESCRIPTION

The getdtablesize() function returns the maximum number of file descriptors that can currently be stored in a process' file descriptor table. This maximum number is also known as the soft limit for open files, and can be adjusted up to the hard limit by calling setrlimit(). The entries in the descriptor table are numbered with small integers starting at 0 (zero).

The getdtablesize() function returns the total number of file descriptors that a process can have open simultaneously. Each process is limited to a current maximum (soft limit) and a fixed upper bound (hard limit) of open file descriptors. This limit is at least 32. The system-defined limits are configurable. See the descriptions of the maxfiles_lim and maxfiles kernel parameters in maxfiles_lim(5) and maxfiles(5), respectively, for information about changing the system-defined, per-process limit on open file descriptors.

RETURN VALUES

The getdtablesize() function returns the size of the descriptor table (soft limit), and is always successful.

SEE ALSO

close(2), getrlimit(2), open(2), select(2), setrlimit(2), sysconf(2), maxfiles(5), maxfiles_lim(5).

STANDARDS CONFORMANCE

getdtablesize(): XSH4.2, XSH5.0