70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include "info.h"
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main(void)
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{
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int i, id;
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struct info *ctrl;
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int v1, v2;
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int choice;
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// create the shared memory segment
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// .. id is the file identifier of the shared memory segment
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// .. if the key is shared, any process can attach to this shared memory segment
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// .. 0666 is the file permission for the shared memory segment
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if ( (id = shmget( KEY,MSIZ,IPC_CREAT | 0666) ) < 0 )
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{
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//error…;
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printf("error 1\n");
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exit(1) ;
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}
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// attach a local pointer to the shared memory segment created
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// .. exit if fails
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if ( (ctrl = (struct info *) shmat( id, 0, 0)) <= (struct info *) (0) )
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{
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//error … ;
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printf("error 2\n");
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exit(1) ;
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}
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ctrl->flag=0;
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ctrl->value1=0;
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ctrl->value1=0;
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ctrl->sum=0;
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while(ctrl->flag!=-1)
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{
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//ctrl->flag=0;
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// ask for numbers and set flag to 1
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printf("Value 1: ");
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scanf("%d",&v1);
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printf("Value 2: ");
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scanf("%d",&v2);
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ctrl->value1 = v1;
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ctrl->value2 = v2;
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ctrl->flag = 1;
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printf("Would you like to continue? Yes(1) or No(-1) : ");
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scanf("%d",&choice);
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if (choice == -1)
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{
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ctrl->flag = -1;
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} else ctrl->flag=0;
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}
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//now detach the pointer from the shared memory
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shmdt(ctrl);
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//let us delete the shared memory
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shmctl(id,IPC_RMID,NULL);
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//job done
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}
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