進程間通信之：消息隊列

以下是消息隊列接收端的代碼：

/*msgrcv.c*/

#includesys/types.h>

#includesys/ipc.h>

#includesys/msg.h>

#includestdio.h>

#includestdlib.h>

#includeunistd.h>

#includestring.h>

#defineBUFFER_SIZE512

structmessage

{

longmsg_type;

charmsg_text[BUFFER_SIZE];

};

intmain()

{

intqid;

key_tkey;

structmessagemsg;

/*根據(jù)不同的路徑和關(guān)鍵字產(chǎn)生標準的key*/

if((key=ftok(.,'a'))==-1)

{

perror(ftok);

exit(1);

}

/*創(chuàng)建消息隊列*/

if((qid=msgget(key,IPC_CREAT|0666))==-1)

{

perror(msgget);

exit(1);

}

printf(Openqueue%dn,qid);

do

{

/*讀取消息隊列*/

memset(msg.msg_text,0,BUFFER_SIZE);

if(msgrcv(qid,(void*)msg,BUFFER_SIZE,0,0)0)

{

perror(msgrcv);

exit(1);

}

printf(Themessagefromprocess%d:%s,msg.msg_type,msg.msg_text);

}while(strncmp(msg.msg_text,quit,4));

/*從系統(tǒng)內(nèi)核中移走消息隊列*/

if((msgctl(qid,IPC_RMID,NULL))0)

{

perror(msgctl);

exit(1);

}

exit(0);

}

以下是程序的運行結(jié)果。輸入“quit”則兩個進程都將結(jié)束。

$./msgsnd

Openqueue327680

Entersomemessagetothequeue:firstmessage

Entersomemessagetothequeue:secondmessage

Entersomemessagetothequeue:quit

$./msgrcv

Openqueue327680

Themessagefromprocess6072:firstmessage

Themessagefromprocess6072:secondmessage

Themessagefromprocess6072:quit