Shared File Table Entries: fork() and dup()
Explore how operating systems manage shared open file table entries through fork and dup system calls. Understand how these calls affect file descriptor sharing between processes and their role in cooperative file operations and output redirection.
In many cases (as in the examples shown in the previous lesson), the mapping of file descriptor to an entry in the open file table is a one-to-one mapping. For example, when a process runs, it might decide to open a file, read it, and then close it; in this example, the file will have a unique entry in the open file table. Even if some other process reads the same file at the same time, each will have its own entry in the open file table. In this way, each logical reading or writing of a file is independent, and each has its own current offset while it ...