read(): The read() command returnsĀ the number of __?___ read.
bytes.
read(): What does the read() system call do?
In modern POSIXcompliant operating systems, aprogram that needs to access data from a file stored in a file system uses this system call.
read(): The file is identified by a file ___?___.
descriptor
read():The file is identified by a file descriptor that is normally obtained from a previous call to __?__.
open
read(): The read system call takes three arguments:
The file descriptor of the file.
The bufferwhere the read data is to be stored
The number of bytes to be readfrom the file.
read(): file descriptor (def'n)
An abstract indicator (handle) used to access a file or other input/output resource, such as a pipe or network socket.
open(): open system call (def')
For most file systems, a program initializesaccess to a file in a file system using this system call. This allocatesresourcesassociated to the file (the file descriptor), and returnsa handlethat the process will use to refer to that file. In some cases thisĀ system call is performed by the first access.
open(): open system call arguments (3):
The pathnameto the file
The kind of access requested on the file (read, write, append etc.)
The initial file permission is requested using the third argument called mode. This argument is relevant only when a new file is being created.
open():pathargument (describe).
The name of the file to open. It includes the file path defining where, in which file system, the file is found (or should be created).
open():oflag argument (describe).
This argumentformed by OR'ing together optional parametersand(from <fcntl.h>) one of the following: O_RDONLY, O_RDWR and O_WRONLY
Author
geschw66
ID
329681
Card Set
Posix System Commands
Description
Fun facts and/or important rules for the POSIX system calls in linux/unix/ios.