Tag: operating systems

1 A dummy device to represent memory

2 A dummy device to represent the processor

3 A dummy device to provide infinite number of zeros

4 None

1 A device file to represent that the current file system is full

2 A device file to test scenarios of testing a /dev/full

3 Invalid device

4 None

1 A dummy device to represent swap

2 A dummy device to represent any device

3 A dummy device to provide infinite number of randon numbers

4 Invalid device

1 True

2 False

3

4

1 lseek(), open(), write(), close()

2 open(), write(), lseek(), close()

3 open(), lseek(), open(), , write() close()

4 None

1 vforlk() allows more one child process to be created simaltaneously whereas for() allows only one

2 vfork() retains same PID for child & parent known as virtual PID

3 vfork() suspends the parent process until child process exits

4 fork() & vfork() are same

1 getenv(), setenv()

2 getenv(), putenv()

3 readenv(), writeenv()

4 You cannot environmement variables inside a program

1 Wakes up kernel from sleeping

2 Wakes up devices from sleeping

3 Invokes a kernel to send SIGALARM to the calling process

4 Invokes a kernel to send SIGALARM to the registered process

1 A memeory shared between kernel & devices

2 A memory shared between root user and ordinary user

3 A memory shared across processes

4 Harddisk

1 The interval between child terminating and the parent calling wait()

2 The interval between parent terminating and the child calling popen()

3 The interval between parent terminating and the child termination

4 None