Learn the Linux Command Open

This system call converts path names into file descriptors

Electric bulb open sign with arrow

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The open() system call linux command converts a pathname into a file descriptor—a small, non-negative integer for use in subsequent I/O as with readwrite, etc. When the call is successful, the file descriptor returned will be the lowest file descriptor not currently open for the process. This call creates a new open file, not shared with any other process.

This system call isn't a command. It's a function used in programming and scripting. Most desktop Linux hobbyists who aren't programmers will never use this system call.