ultrix man page for munmap

munmap(2)							System Calls Manual							 munmap(2)

Name
       munmap - unmaps memory of a character device

Syntax
       #include <sys/types.h>
       #include <sys/mman.h>

       caddr_t munmap(addr, len)
       caddr_t addr;
       size_t len;

Arguments
       addr	 Specifies the address space of the calling process at which the unmapping begins.

       len	 Specifies the number of bytes to unmap.

Description
       The  system  call  unmaps  a  specified	number of bytes (len) starting at a specified address (addr) from the address space of the calling
       process.  You mapped this device in a previous call to Subsequent access to the unmapped region results in  a  signal.	You  cannot  unmap
       data, stack, and text segments using

       The system call rounds len to the nearest multiple of page size as returned by

       The range [addr, addr + len] may contain more than one mapped region created by In this case, unmaps all of the mapped regions.

Restrictions
       All  of	the  mapped  regions must be wholly contained in the range [addr, addr + len].	That is, addr must be the beginning of some mapped
       region and addr + len must be the end of some (possibly different) mapped region.

Return Value
       If successful, returns 0.  Otherwise, it returns -1 and sets the errno argument to one of the errors listed in the Diagnostics section.

Diagnostics
       The call to fails if one or more of the following is true:

       [EINVAL]  The address you specified in addr is not a multiple of the page size as returned by

       [EINVAL]  The addresses in the range [addr, addr + len] are not valid in the process address space.

       [EINVAL]  All of the segments being unmapped are not entirely contained in the range [addr, addr + len].

See Also
       getpagesize(2), getsysinfo(2), mmap(2)

																	 munmap(2)