Opening and Closing files: Using “Open” function, a process can open an existing file or generates a new file. This function is used to converts a filename to a file descriptor and returns the result as a descriptor number. The descriptor returned is always the lowest descriptor that is not presently open in the process. Each process in the LINUX begins life with three open files. Descriptor 0 – standard input. Descriptor 1 – standard output. Descriptor 2 – standard error. The “open” function consists of three arguments. That is “Open(filename, flags, mode)”. The argument “filename” defines the name of the given file. The argument “flags” represents how the process plans to access the file. Some flags names are as follows. O_RDONLY – it means reading only. O_WRONLY – it means writing only. O_RDWR – it means reading and writing. The “mode” argument identifies the access permission bits of new files. Example: The example for open an existing file for reading is shown below: sample1 = Open("foo1.txt", O_RDONLY, 0); From the above “open” function, The filename is “foo1.txt”. Flag name is “O_RDONLY”. Mode is “0”.

Question

Want to see the full answer?

Answer 1

Question

Chapter 10.3, Problem 10.1PP

Program Plan Intro

Opening and Closing files:

Using “Open” function, a process can open an existing file or generates a new file.

This function is used to converts a filename to a file descriptor and returns the result as a descriptor number.

The descriptor returned is always the lowest descriptor that is not presently open in the process.

Each process in the LINUX begins life with three open files.

Descriptor 0 – standard input.

Descriptor 1 – standard output.

Descriptor 2 – standard error.

The “open” function consists of three arguments. That is “Open(filename, flags, mode)”.

The argument “filename” defines the name of the given file.

The argument “flags” represents how the process plans to access the file. Some flags names are as follows.

O_RDONLY – it means reading only.

O_WRONLY – it means writing only.

O_RDWR – it means reading and writing.

The “mode” argument identifies the access permission bits of new files.

Example:

The example for open an existing file for reading is shown below:

sample1 = Open("foo1.txt", O_RDONLY, 0);

From the above “open” function,

The filename is “foo1.txt”.

Flag name is “O_RDONLY”.

Mode is “0”.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

3. Problem Description: Define the Circle2D class that contains: Two double data fields named x and y that specify the center of the circle with get methods. • A data field radius with a get method. • A no-arg constructor that creates a default circle with (0, 0) for (x, y) and 1 for radius. • A constructor that creates a circle with the specified x, y, and radius. • A method getArea() that returns the area of the circle. • A method getPerimeter() that returns the perimeter of the circle. • • • A method contains(double x, double y) that returns true if the specified point (x, y) is inside this circle. See Figure (a). A method contains(Circle2D circle) that returns true if the specified circle is inside this circle. See Figure (b). A method overlaps (Circle2D circle) that returns true if the specified circle overlaps with this circle. See the figure below. р O со (a) (b) (c)< Figure (a) A point is inside the circle. (b) A circle is inside another circle. (c) A circle overlaps another…

1. Explain in detail with examples each of the following fundamental security design principles: economy of mechanism, fail-safe default, complete mediation, open design, separation of privilege, least privilege, least common mechanism, psychological acceptability, isolation, encapsulation, modularity, layering, and least astonishment.

Security in general means the protection of an asset. In the context of computer and network security, explore and explain what assets must be protected within an online university. What the threats are to the security of these assets, and what countermeasures are available to mitigate and protect the organization from such threats. For each of the assets you identify, assign an impact level (low, moderate, or high) for the loss of confidentiality, availability, and integrity. Justify your answers.