CLOSEFROM(2)              FreeBSD System Calls Manual             CLOSEFROM(2)

NAME
     closefrom, close_range - delete open file descriptors

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     void
     closefrom(int lowfd);

     int
     close_range(u_int lowfd, u_int highfd, int flags);

DESCRIPTION
     The closefrom() system call deletes all open file descriptors greater
     than or equal to lowfd from the per-process object reference table.  Any
     errors encountered while closing file descriptors are ignored.

     The close_range() system call deletes all open file descriptors between
     lowfd and highfd inclusive, clamped to the range of open file
     descriptors.  Any errors encountered while closing file descriptors are
     ignored.  Supported flags:

     CLOSE_RANGE_CLOEXEC      Set the close-on-exec flag on descriptors in the
                              range instead of closing them.

RETURN VALUES
     Upon successful completion, close_range() returns a value of 0.
     Otherwise, a value of -1 is returned and the global variable errno is set
     to indicate the error.

ERRORS
     The close_range() system call will fail if:

     [EINVAL]           The highfd argument is lower than the lowfd argument.

     [EINVAL]           An invalid flag was set.

SEE ALSO
     close(2)

HISTORY
     The closefrom() function first appeared in FreeBSD 8.0.

FreeBSD 13.1-RELEASE-p6          March 3, 2022         FreeBSD 13.1-RELEASE-p6