JuliaLang/julia

wanted: `open(create=true, exclusive=true)` dead or alive

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#33,947 opened on Nov 26, 2019

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 (2 comments) (1 reaction) (0 assignees)Julia (5,773 forks)batch import
featuregood first issue

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Description

Sometimes useful, for creating atomic lockfiles (https://github.com/vtjnash/Pidfile.jl) or secure tempfiles: https://github.com/JuliaLang/julia/blob/31bf76f8a1719e07612b9af4196bfc924cf73e21/base/file.jl#L586

The exclusive=true flag (only valid in combination with create=true) should simply map the the underlying O_EXCL option to open (this exists everywhere that Julia runs).

(could also try to add O_NOFOLLOW, though FILE_FLAG_OPEN_REPARSE_POINT is more like O_SYMLINK, and so is hard to implement everywhere. And there's a couple others like RANDOM, SEQUENTIAL, SYNC, DSYNC, NOATIME, DIRECT, and SHORT_LIVED that could even be filtered out when not supported.)

Contributor guide

Research direction
Investigate how to add the `exclusive=true` option to the `open` function by mapping it to the `O EXCL` flag in system calls, considering cross platform support (Unix, Windows) and potential edge cases like atomic lockfiles.
Tech stack
None
Domain
api
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Juliafile I/Osystem calls
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60