munmap(2) munmap(2) NAME munmap - unmap pages of memory SYNOPSIS #include <sys/mman.h> int munmap(void *addr, size_t len); DESCRIPTION The munmap() function removes the mappings for pages in the range [addr, addr+len], rounding the len argument up to the next multiple of the page size as returned by sysconf(). If addr is not the address of a mapping established by a prior call to mmap(), the behaviour is undefined. After a successful call to munmap() and before any subsequent mapping of the unmapped pages, further references to these pages will result in the delivery of a SIGBUS or SIGSEGV signal to the process. RETURN VALUE Upon successful completion, munmap() returns 0. Otherwise, it returns -1 and sets errno to indicate the error. ERRORS The munmap() function will fails if: [EINVAL] The addr argument is not a multiple of the page size as returned by sysconf(). [EINVAL] Addresses in the range [addr, addr+len], are outside the valid range for the address space of a process. [EINVAL] The len argument is 0. SEE ALSO mmap*() , sysconf() , <signal.h> , <sys/mman.h> . CHANGE HISTORY First released in Issue 4, Version 2. - 1 - Formatted: April 25, 2001 munmap(2) munmap(2) HP-UX EXTENSIONS SYNOPSIS int munmap(caddr_t addr, size_t len); DESCRIPTION munmap() unmaps a mapped file or anonymous memory region. If the address range specified by addr and len was not created by a successful call to mmap(), munmap() returns an error. If the specified address range was created by multiple calls to mmap(), munmap() succeeds in unmapping all of the specified regions, provided they form a contiguous address range. If the region was created with the MAP_PRIVATE option, any modifications made to the region are discarded. ERRORS [EINVAL] addr is not a multiple of the page size as returned by sysconf(_SC_PAGE_SIZE). [EINVAL] The address range specified by addr and len was not created by a successful call to mmap(). AUTHOR munmap() was developed by HP, AT&T, and OSF. SEE ALSO mmap(2), sysconf(2). STANDARDS CONFORMANCE munmap(): AES, SVID3 Hewlett-Packard Company - 1 - HP-UX Release 10.20: July 1996