shmget KEY, SIZE, FLAGS shmget KEY |
返回共享內存段段匹配的密鑰ID。創建一個新的共享內存段,提供至少SIZE字節,要麼已經冇有KEY或KEY段到常數IPC_PRIVATE。
undef - 失敗時
共享內存ID
試試下麵的例子:
#!/usr/bin/perl # Assume this file name is writer.pl use IPC::SysV; #use these next two lines if the previous use fails. eval 'sub IPC_CREAT {0001000}' unless defined &IPC_CREAT; eval 'sub IPC_RMID {0}' unless defined &IPC_RMID; $key = 12345 $size = 80; $message = "Pennyfarthingale."; # Create the shared memory segment $key = shmget($key, $size, &IPC_CREAT | 0777 ) or die "Can't shmget: $!"; # Place a string in itl shmwrite( $id, $message, 0, 80 ) or die "Can't shmwrite: $!"; sleep 20; # Delete it; shmctl( $id, &OPC_RMID, 0 ) or die "Can't shmctl: $! ";
寫讀取程序中的內存段對應於$key,並讀取其內容使用shmread();。
#!/usr/bin/perl # Assume this file name is reader.pl # by www.gitbook.net $key = 12345; $size = 80; # Identify the shared memory segment $id = shmget( $key, $size, 0777 ) or die "Can't shmget: $!"; # Read its contents itno a string shmread($id, $var, 0, $size) or die "Can't shmread: $!"; print $var;
現在首先運行writer.pl的程序在後台和然後reader.pl然後它會產生以下結果。
$perl writer.pl&
$perl reader.pl Pennyfrathingale