Computer World. Матросова Т.А. - 51 стр.

UptoLike

ВУЗ: 

УлГТУ | Ульяновск

Составители: 

Рубрика: 

50
TEXT 4
Translate the text without a dictionary.
SECURI TY AND UNIX
Dennis Ritchie wrote about the security of UNIX: «It was not designed from the
start to be secure. It was designed with the necessary characteristics to make security
servic eable.»
UNIX is a mult i-us er, multi-tas king operat ing system. Multi-us er means that the
operating system allows many different people to use the same computer at the same
time. Multi-tasking means that each user can run many different programs
simultaneous ly.
One of the natural functions of such operating systems is to prevent different
people (or programs) using the same computer from interfering with each other.
Without such protection, a wayward program (perhaps written by a student in an
introductory computer science course) could affect other programs or other users,
could accidentally delete files, or could even crash (halt) the entire computer system.
To keep such disasters from happening, some form of computer security has always
had a place in the UNIX design philosophy.
But UNIX security provides more than mere memory protection. UNIX has a
sophisticated security system that controls the ways users access files, modify system
databases, and use system resources. Unfortunately, those mechanisms don't help
much when the systems are misconfigured, are used carelessly, or contain buggy
software. Nearly all of the security holes that have been found in UNIX over the
years have resulted from these kinds of problems rather than from shortcomings in
the intrinsic design of the system. Thus, nearly all UNIX vendors believe that they
can (and perhaps do) provide a reasonably secure UNIX operating system.
TEXT 5
Read the text with a dictionary. Discuss the following in pairs:
Is Plan9 similar to UNIX?
Write an abstract of the text.
UNIX'S LITTLE BRO THER
Bell Labs’ s Plan 9, named after a c ult sci-fi film, resembles UNIX in many
ways. Like UNIX, Plan 9 was designed as a time sharing operating system primarily
for software developers. Like UNIX, it is a file-based operating system intended to be
portable between hardware environments. Plan 9 even shares some of UNIX’s
original developers. Along with Bell Labs research scientists Rob Pike, Dave
Presotto, Howard Trickey, UNIX originator Ken Thompson is credited as a primary
designer of Plan 9. Thompson created Plan 9’s fileserver and initial complier. UNIX
cocreator Dennis Ritchie also helped on the project.
But Plan 9 differs from UNIX–and trends occurring in the UNIX world to day–
in some important ways. For example Plan 9 rejects the currently popular idea of an

Страницы