the syscalls for files are open(), close(), read() and _____
write()
the _____ syscall adds a directory entry (hard link?)
link
the syscall _____ opens/creates a file and returns a file descriptor
open
The command _____ traces signals and system calls
strace
the syscalls for files are open(), close(), _____ and write()
read()
the syscalls for files are open(), _____, read() and write()
close()
A signal's _____ must perform a default action, invoke a handler function, block, or ignore it.
receiving process
The kernel code and function stubs used by each process are stored within _____
The address space pages of each process
each process has 3 user IDs: _____ effective ID (determines privileges) saved ID (set by exec to match the effective ID)
real ID (the owning user)
the _____ syscall makes a symbolic link
symlink
the syscall _____ releases a file descriptor
close
each process has 3 user IDs: real ID (the owning user) effective ID (determines privileges) _____
saved ID (set by exec to match the effective ID)
_____ gets/sets default permissions for new files/directories created henceforth by a process.
umask
Signals can either be sent by the kernel or _____
the kill syscall
How many users can a file or directory be owned by at most? _____
One
Can exec can change IDs of files via setuid? _____
Yes
the file permission classes are _____, group, other
user
each file and directyory in a partition is known by a unique inode _____
number
The command strace _____
traces signals and system calls
the syscall _____ copies bytes from of memory to a file. Blocks
write
_____ expose functionalities of the operating system to programs.
system calls
"_____ performs ""memory mapping"" of pages to the process address space. munmap can then be used to unmap them."
mmap
A _____ represents one end of a connection as a channel of communication.
socket
"mmap performs ""memory mapping"" of pages to the process address space. _____ can then be used to unmap them."
munmap
the file permission classes are user, _____, other
group
the _____ for files are open(), close(), read() and write()
syscalls
_____ changes permissions of an existing file/directory. The invoking process' EUID must be 0, or match the owner of that file/directory.
chmod
Signals can either be sent by _____ or the kill syscall
the kernel
a partition's root directory always has inode number _____
2
the syscall _____ copies bytes from a file to memory. Blocks.
read
each process has 3 user IDs: real ID (the owning user) _____ saved ID (set by exec to match the effective ID)
effective ID (determines privileges)
_____ changes the owner of an existing file/directory. The EUID of the invoker must be 0 or the owner of the file/directory.
chown
A file is ready to be released/overwritten once its _____'s link count equals 0.
inode
the syscalls for files are _____, close(), read() and write()
open()
Are syscalls ran inside the kernel? _____
No - they're only ever called from inside a process. Every process has its own copy of available syscall definitions inside its address space. This avoids making a CPU-expensive context switch to the kernel.
the file permission classes are user, group, _____
other