Simple Process program problems?

Simple Process program problems? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. # Include
# Include
# Include
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# Include
# Include

Int main ()
{
Int shmid;
Char * shmptr;
If (shmid = shmget (IPC_PRIVATE, 1000,0) <0)
{
Printf ("Here is the server: error, get share memeroy failed! \ N ");
Exit (1 );
}
If (shmptr = (void *) shmat (shmid, 0, 0) = (void *)-1)
{
Printf ("Here is the server: error, to make the shmat \ n ");
Exit (1 );
}
Shmptr = "Hello World ";
If (system ("./receiver") <0)
{
Printf ("Here is the server: System error ");

}
Sleep (320 );
Return 0;
}
When running this program, an error is reported:
Here is the server: error, to make the shmat
I don't know why. hope you can give me some advice...