CODEWITHSUNDEEP
cfileoperating-systemfile-descriptor
UtkarshPramodGupta
UtkarshPramodGupta

Reputation: 8152

File descriptor and process relation

Do file descriptor are with respect to the processes or with respect to the operating system? What I basically want to know is if in a c program I open a file and that file gets assigned a file descriptor value lets say, 103, so when I open a file with file descriptor 103 in some other c program would I be referring to the same file or some other?

Upvotes: 1

Views: 375

Answers (2)

incompetent
incompetent

Reputation: 1822

File descriptors are process specific created through open(). But you can open same file more than once by other processes with open(). In this way each process will have his own file descriptor for same file. File descriptors along with other resources pass through fork to child process.That means child process does not need to reopen same file which parent already has opened.

Upvotes: 0

Dilip Kumar
Dilip Kumar

Reputation: 1746

Each Process will be having its own file descriptor table. Its processor specific, if you change the fd it will be valid only to that process it wont affect the other processes in the system. once process is terminated fd will be discarded.

What if I fork a new process from the process I opened that file?

Current File description table i.e the table before fork system call will be inherited to the child process.

Upvotes: 1

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