I cosign all of this. Nice work, Brent. > On Nov 17, 2017, at 4:47 PM, Brent Royal-Gordon via swift-corelibs-dev > <swift-corelibs-dev@swift.org> wrote: > >> On Nov 17, 2017, at 11:34 AM, Tony Parker via swift-corelibs-dev >> <swift-corelibs-dev@swift.org <mailto:swift-corelibs-dev@swift.org>> wrote: >> >> It does seem like there is a possibility of some better convenience API here. >> >> Any ideas on what form it would take? A class method on Process that returns >> the output, maybe? > > `Process.run(_:arguments:terminationHandler:)` is not a bad basis for this, > other than the first argument being a URL. I might add a variant which does a > $PATH search and expands tildes: > > extension Process { > class func runInPath(_ commandName: String, with arguments: > [String], terminationHandler: ((Process) -> Void)? = nil) -> Process > } > > (I would *not* add a variant which simply shells out, or at least I wouldn't > make it the only option. Every scripting language I can think of has this > feature, and every one of them discourages its use and pushes people towards > something else with pre-split arguments and no shell attack surface.) > > And then add a method which gathers all stdout output and returns it, along > with the termination status (throwing if it's a signal): > > extension Process { > func outputAfterExit() throws -> (output: String, status: Int32) > } > > The result is not *as* convenient as PHP, but it's a lot safe than running > things through a shell, too. > > let (output, _) = try Task.runInPath("find", with: ["~/Desktop", > "-name", "*.png"]).outputAfterExit() > > The biggest problem I see with this design is that expanding tildes in the > arguments, but *not* globbing them, happens to be right for this case, but > may not be in the general case. One interesting possibility would be to go > the custom operator route: > > /// Returns an absolute path placing `relativePath` in the user's home > directory. > prefix func ~ (relativePath: String) -> String { > return > FileManager.default.homeDirectoryForCurrentUser.appendingPathComponent(relativePath).path > } > > let (output, _) = try Task.runInPath("find", with: [~"Desktop", > "-name", "*.png"]).outputAfterExit() > > But I'm not sure we'd want that available in million-line Mac apps. > > On the other hand, maybe Foundation's APIs in general are too verbose for > scripting. I could imagine a "Foundation.Script" module which added some > unprincipled but convenient shortcuts: > > extension URL: ExpressibleByStringLiteral { // Should be > interpolatable too, but we need to redesign that. > public init(stringLiteral value: String) { > self.init(fileURLWithPath: value) > } > } > public var FS { return FileManager.default } > public var ENV { return ProcessInfo.processInfo.environment } > > That might be a good place for a leading tilde operator, too. > > -- > Brent Royal-Gordon > Architechies > > _______________________________________________ > swift-corelibs-dev mailing list > swift-corelibs-dev@swift.org > https://lists.swift.org/mailman/listinfo/swift-corelibs-dev
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