Kernel Mapping of File Descriptors

The kernel mapping of a file descriptor to the corresponding file. The system-wide File Table contains entries for all of the open files on the system. UNIX/Linux allocates an inode to every (unique) file on the system to store most of the attributes, including file's location. On a read or write call, kernel traverses this mapping to reach the corresponding file.

Figure of the File descriptors and their mapping to files

Standard Descriptors in Unix/Linux is described below

Three files are automatically opened by the kernel for every process for the process to read its input from and send its output and error messages to. These files are known as standard files: standard output, standard input, and standard error. By default, standard files are attached to the terminal on which a process runs. The descriptors for standard files are known as standard file descriptors. Standard files, their descriptors, and their default attachments are:

1)   Standard input   0 (keyboard)

2)   Standard output 1 (display screen)

3)   Standard error     2 (display screen)

The pipe() System Call

We discussed the pipe() system call in the notes for lecture 8. The pipe() system call fails for many reasons, including the following:

1)   At least two slots are not empty in the PPFDT-too many files or pipes are open in the process

2)   Buffer space not available in the kernel

3)   File table is full

Email based Operating System  assignment help - homework help at Expertsmind

Are you searching Operating System expert for help with Standard Descriptors questions?  Standard Descriptors topic is not easier to learn without external help?  We at www.expertsmind.com offer finest service of operating system assignment help and operating system homework help. Live experts are available for 24x7 hours helping students in their Standard Descriptors related problems. We provide step by step Standard Descriptors question's answers with 100% plagiarism free content. We prepare quality content and notes for Standard Descriptors topic under operating system theory and study material. These are avail for subscribed users and they can get advantages anytime.

Why Expertsmind for assignment help

1. Higher degree holder and experienced tutors network
2. Punctuality and responsibility of work
3. Quality solution with 100% plagiarism free answers
4. Time on Delivery
5. Privacy of information and details
6. Excellence in solving operating system questions in excels and word format.
7. Best tutoring assistance 24x7 hours