1 files changed, 69 insertions, 0 deletions
diff --git a/ext/shmop/README b/ext/shmop/README
new file mode 100644
index 0000000..5ec1586
--- /dev/null
+++ b/ext/shmop/README
@@ -0,0 +1,69 @@
+last update Jan 2, 2002 (hackie@prohost.org/ilia@prohost.org)
+
+Shared Memory Operations Extension to PHP
+
+	While developing a search deamon we needed a php based front end
+	to communicate the deamon via SHM. PHP already had a shared memory
+	extention (sysvshm) written by Christian Cartus <cartus@atrior.de>,
+	unfortunatly this extention was designed with PHP only in mind and
+	offers high level features which are extremly bothersome for basic SHM
+	we had in mind.  After spending a day trying to reverse engineer and figure
+	out the format of sysvshm we decided that it would be much easier to
+	add our own extention to php for simple SHM operations, we were right :)). 
+
+the functions are:
+	
+int shmop_open(int key, string flags, int mode, int size)
+	
+	key 		- the key of/for the shared memory block
+	flags 		- 4 flags are avalible 
+				a for read only access (sets SHM_RDONLY)
+				w for read & write access
+				c create or open an existing segment (sets IPC_CREATE)
+				n create a new segment and fail if one already exists under same name (sets IPC_CREATE|IPC_EXCL)
+				(the n flag is mostly useful for security perpouses, so that you don't end up opening a faked segment 
+				if someone guesses your key)
+	mode		- acsess mode same as for a file (0644) for example
+	size		- size of the block in bytes
+	
+	returns an indentifier
+	
+
+char shmop_read(int shmid, int start, int count)
+
+	shmid		- shmid from which to read
+	start		- offset from which to start reading
+	count		- how many bytes to read
+	
+	returns the data read
+
+int shmop_write(int shmid, string data, int offset)
+
+	shmid		- shmid from which to read
+	data		- string to put into shared memory
+	offset		- offset in shm to write from
+	
+	returns bytes written
+	
+int shmop_size(int shmid)
+
+	shmid 		- shmid for which to return the size
+	
+	returns the size in bytes of the shm segment
+	
+	
+int shmop_delete(int shmid)
+
+	marks the segment for deletion, the segment will be deleted when all processes mapping it will detach
+
+	shmid		- shmid which to mark for deletion
+	
+	returns 1 if all ok, zero on failure
+	
+int shmop_close(int shmid)
+
+	shmid 		- shmid which to close
+	
+	returns zero
+	
+