使用共享内存时子进程挂起？
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我正在从一些C代码中得到一些非常奇怪的输出。当然，我是C和Linux开发的新手，因为我的背景是.NET和C＃。
无论如何，我都应该在c中编写FAT12实现和命令外壳。每当子进程尝试访问共享内存时，我的外壳就会挂起。事实上，什么也没有发生，这真的很奇怪。谁能帮我调试代码？
谢谢，
这是运行shell的主循环：
while(strcmp(input, \"EXIT\") != 0 )
{
scanf(\"%s\", input);
input = String_ToFixedArray(input);
array = StringArray_Create(input, \" \"); //split the input string into array.
if( array->Items == NULL || array->Size == 0 )
{
input = \"CONTINUE\";
continue;
}
if( strcmp(String_ToUpper(array->Items[0]), \"PBS\") == 0)
{
pid_t processId;
if((processId = fork()) < 0 )
{
printf(\"%s\", \"Error executing command.\");
}
//child process. Nothing happens???????
if( processId == 0 )
{
ExecutePBS();
}
}
else if( strcmp(String_ToUpper(array->Items[0]), \"PFE\") == 0 )
{
printf(\"Execute Print Fat Entries (PFE) Command\\n\");
}
else if( strcmp(String_ToUpper(array->Items[0]), \"EXIT\") == 0 )
{
printf(\"Exiting..\");
break;
}
else
{
input = \"CONTINUE\";
}
}
void ExecutePBS(void)
{
int shm_file_id;
char* shm_file;
char* shm_file_ptr;
struct shmid_ds shm_file_buffer;
if( (shm_file_id = shmget(SHM_FILE_NAME_KEY,SHM_FILE_NAME_SIZE, 0666)) < 0)
{
perror(\"Error locating shared memory segment.\");
exit(1);
}
if((shm_file = shmat(shm_file_id, NULL, 0)) == (char *) -1)
{
perror(\"Error attaching shared memory segment to process\' scope.\");
exit(1);
}
if(shmctl(shm_file_id, IPC_STAT, &shm_file_buffer) == -1 )
{
perror(\"Error while attempting to control the shared memory segment used to store the floppy file name for IPC.\");
exit(1);
}
sprintf(shm_file_ptr, \"%s\", shm_file);
if( shmdt(shm_file) == -1)
{
perror(\"Error releasing shared memory.\");
exit(1);
}
FILE* floppyImage = fopen(shm_file_ptr, \"r+\");
if (floppyImage == NULL)
{
printf(\"Could not open the floppy drive or image.\\n\");
exit(1);
}
BootSector* bootSector = BootSector_ReadBootSector(floppyImage);
BootSector_ToString(bootSector);
return;
}
没有找到相关结果
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