Proposal v4 changes

Package.swift

@@ -64,7 +64,10 @@ var dependencies: [Package.Dependency] {
                 exact: "0.0.8"),
             .package(
                 url: "https://github.com/swiftlang/swift-syntax",
-                from: "600.0.0-latest")
+                from: "600.0.0-latest"),
+            .package(
+                url: "https://github.com/apple/swift-system",
+                from: "1.0.0")
         ]
     }
 }

Sources/FoundationEssentials/Subprocess/Platforms/Subprocess+Darwin.swift

@@ -15,9 +15,9 @@ import Darwin
 import SystemPackage
 
 #if FOUNDATION_FRAMEWORK
-@_implementationOnly import _CShims
+@_implementationOnly import _FoundationCShims
 #else
-package import _CShims
+internal import _FoundationCShims
 #endif
 
 // Darwin specific implementation
@@ -147,10 +147,10 @@ extension Subprocess.Configuration {
             }
         }
         // Run additional config
-        if let spawnConfig = self.platformOptions.additionalSpawnAttributeConfigurator {
+        if let spawnConfig = self.platformOptions.preSpawnAttributeConfigurator {
             try spawnConfig(&spawnAttributes)
         }
-        if let fileAttributeConfig = self.platformOptions.additionalFileAttributeConfigurator {
+        if let fileAttributeConfig = self.platformOptions.preSpawnFileAttributeConfigurator {
             try fileAttributeConfig(&fileActions)
         }
         // Spawn
@@ -203,8 +203,8 @@ extension Subprocess {
         // Create a new process group
         public var createProcessGroup: Bool = false
         public var launchRequirementData: Data? = nil
-        public var additionalSpawnAttributeConfigurator: (@Sendable (inout posix_spawnattr_t?) throws -> Void)?
-        public var additionalFileAttributeConfigurator: (@Sendable (inout posix_spawn_file_actions_t?) throws -> Void)?
+        public var preSpawnAttributeConfigurator: (@Sendable (inout posix_spawnattr_t?) throws -> Void)?
+        public var preSpawnFileAttributeConfigurator: (@Sendable (inout posix_spawn_file_actions_t?) throws -> Void)?
 
         public init(
             qualityOfService: QualityOfService,

Sources/FoundationEssentials/Subprocess/Platforms/Subprocess+Linux.swift

@@ -14,7 +14,7 @@
 import Glibc
 import SystemPackage
 import FoundationEssentials
-package import _CShims
+package import _FoundationCShims
 
 // Linux specific implementations
 extension Subprocess.Configuration {

Sources/FoundationEssentials/Subprocess/Platforms/Subprocess+Unix.swift

@@ -21,9 +21,9 @@ import Glibc
 import SystemPackage
 
 #if FOUNDATION_FRAMEWORK
-@_implementationOnly import _CShims
+@_implementationOnly import _FoundationCShims
 #else
-package import _CShims
+package import _FoundationCShims
 #endif
 
 import Dispatch
@@ -283,7 +283,7 @@ internal func monitorProcessTermination(
             var status: Int32 = -1
             waitpid(pid.value, &status, 0)
             if _was_process_exited(status) != 0 {
-                continuation.resume(returning: .exit(_get_exit_code(status)))
+                continuation.resume(returning: .exited(_get_exit_code(status)))
                 return
             }
             if _was_process_signaled(status) != 0 {

Sources/FoundationEssentials/Subprocess/Subprocess+API.swift

@@ -129,10 +129,10 @@ extension Subprocess {
         workingDirectory: FilePath? = nil,
         platformOptions: PlatformOptions = .default,
         input: InputMethod = .noInput,
-        output: RedirectedOutputMethod = .redirect,
-        error: RedirectedOutputMethod = .discard,
+        output: RedirectedOutputMethod = .redirectToSequence,
+        error: RedirectedOutputMethod = .redirectToSequence,
         _ body: (@Sendable @escaping (Subprocess) async throws -> R)
-    ) async throws -> Result<R> {
+    ) async throws -> ExecutionResult<R> {
         return try await Configuration(
             executable: executable,
             arguments: arguments,
@@ -150,10 +150,10 @@ extension Subprocess {
         workingDirectory: FilePath? = nil,
         platformOptions: PlatformOptions,
         input: some Sequence<UInt8>,
-        output: RedirectedOutputMethod = .redirect,
-        error: RedirectedOutputMethod = .discard,
+        output: RedirectedOutputMethod = .redirectToSequence,
+        error: RedirectedOutputMethod = .redirectToSequence,
         _ body: (@Sendable @escaping (Subprocess) async throws -> R)
-    ) async throws -> Result<R> {
+    ) async throws -> ExecutionResult<R> {
         return try await Configuration(
             executable: executable,
             arguments: arguments,
@@ -175,10 +175,10 @@ extension Subprocess {
         workingDirectory: FilePath? = nil,
         platformOptions: PlatformOptions = .default,
         input: S,
-        output: RedirectedOutputMethod = .redirect,
-        error: RedirectedOutputMethod = .discard,
+        output: RedirectedOutputMethod = .redirectToSequence,
+        error: RedirectedOutputMethod = .redirectToSequence,
         _ body: (@Sendable @escaping (Subprocess) async throws -> R)
-    ) async throws -> Result<R> where S.Element == UInt8 {
+    ) async throws -> ExecutionResult<R> where S.Element == UInt8 {
         return try await Configuration(
             executable: executable,
             arguments: arguments,
@@ -199,10 +199,10 @@ extension Subprocess {
         environment: Environment = .inherit,
         workingDirectory: FilePath? = nil,
         platformOptions: PlatformOptions = .default,
-        output: RedirectedOutputMethod = .redirect,
-        error: RedirectedOutputMethod = .discard,
+        output: RedirectedOutputMethod = .redirectToSequence,
+        error: RedirectedOutputMethod = .redirectToSequence,
         _ body: (@Sendable @escaping (Subprocess, StandardInputWriter) async throws -> R)
-    ) async throws -> Result<R> {
+    ) async throws -> ExecutionResult<R> {
         return try await Configuration(
             executable: executable,
             arguments: arguments,
@@ -217,11 +217,11 @@ extension Subprocess {
 // MARK: - Configuration Based
 extension Subprocess {
     public static func run<R>(
-        withConfiguration configuration: Configuration,
-        output: RedirectedOutputMethod = .redirect,
-        error: RedirectedOutputMethod = .redirect,
+        using configuration: Configuration,
+        output: RedirectedOutputMethod = .redirectToSequence,
+        error: RedirectedOutputMethod = .redirectToSequence,
         _ body: (@Sendable @escaping (Subprocess, StandardInputWriter) async throws -> R)
-    ) async throws -> Result<R> {
+    ) async throws -> ExecutionResult<R> {
         return try await configuration.run(output: output, error: error, body)
     }
 }

Sources/FoundationEssentials/Subprocess/Subprocess+AsyncBytes.swift

@@ -13,7 +13,9 @@ import SystemPackage
 import Dispatch
 
 extension Subprocess {
-    public struct AsyncBytes: AsyncSequence, Sendable {
+    public struct AsyncBytes: AsyncSequence, Sendable, _AsyncSequence {
+        public typealias Error = any Swift.Error
+
         public typealias Element = UInt8
 
         @_nonSendable
@@ -104,3 +106,7 @@ extension RangeReplaceableCollection {
         }
     }
 }
+
+public protocol _AsyncSequence<Element, Error>: AsyncSequence {
+    associatedtype Error
+}

Sources/FoundationEssentials/Subprocess/Subprocess+Configuration.swift

@@ -12,9 +12,9 @@
 @preconcurrency import SystemPackage
 
 #if FOUNDATION_FRAMEWORK
-@_implementationOnly import _CShims
+@_implementationOnly import _FoundationCShims
 #else
-package import _CShims
+package import _FoundationCShims
 #endif
 
 #if canImport(Darwin)
@@ -182,7 +182,7 @@ extension Subprocess {
             output: RedirectedOutputMethod,
             error: RedirectedOutputMethod,
             _ body: @Sendable @escaping (Subprocess, StandardInputWriter) async throws -> R
-        ) async throws -> Result<R> {
+        ) async throws -> ExecutionResult<R> {
             let (readFd, writeFd) = try FileDescriptor.pipe()
             let executionInput: ExecutionInput = .init(storage: .customWrite(readFd, writeFd))
             let executionOutput: ExecutionOutput = try output.createExecutionOutput()
@@ -238,7 +238,7 @@ extension Subprocess {
                             result = workResult
                         }
                     }
-                    return Result(terminationStatus: terminationStatus, value: result)
+                    return ExecutionResult(terminationStatus: terminationStatus, value: result)
                 }
             } onCancel: {
                 // Attempt to terminate the child process
@@ -258,7 +258,7 @@ extension Subprocess {
             output: RedirectedOutputMethod,
             error: RedirectedOutputMethod,
             _ body: (@Sendable @escaping (Subprocess) async throws -> R)
-        ) async throws -> Result<R> {
+        ) async throws -> ExecutionResult<R> {
             let executionInput = try input.createExecutionInput()
             let executionOutput = try output.createExecutionOutput()
             let executionError = try error.createExecutionOutput()
@@ -311,7 +311,7 @@ extension Subprocess {
                             result = workResult
                         }
                     }
-                    return Result(terminationStatus: terminationStatus, value: result)
+                    return ExecutionResult(terminationStatus: terminationStatus, value: result)
                 }
             } onCancel: {
                 // Attempt to terminate the child process
@@ -484,7 +484,7 @@ extension Subprocess {
 
 // MARK: - TerminationStatus
 extension Subprocess {
-    public enum TerminationStatus: Sendable, Hashable {
+    public enum TerminationStatus: Sendable, Hashable, Codable {
         #if canImport(WinSDK)
         public typealias Code = DWORD
         #else
@@ -495,12 +495,12 @@ extension Subprocess {
         case stillActive
         #endif
 
-        case exit(Code)
+        case exited(Code)
         case unhandledException(Code)
 
         public var isSuccess: Bool {
             switch self {
-            case .exit(let exitCode):
+            case .exited(let exitCode):
                 return exitCode == 0
             case .unhandledException(_):
                 return false
@@ -509,7 +509,7 @@ extension Subprocess {
 
         public var isUnhandledException: Bool {
             switch self {
-            case .exit(_):
+            case .exited(_):
                 return false
             case .unhandledException(_):
                 return true

Sources/FoundationEssentials/Subprocess/Subprocess+IO.swift

@@ -40,8 +40,8 @@ extension Subprocess {
             return .init(method: .noInput)
         }
 
-        public static func readFrom(_ fd: FileDescriptor, closeWhenDone: Bool) -> Self {
-            return .init(method: .fileDescriptor(fd, closeWhenDone))
+        public static func readFrom(_ fd: FileDescriptor, closeAfterProcessSpawned: Bool) -> Self {
+            return .init(method: .fileDescriptor(fd, closeAfterProcessSpawned))
         }
     }
 }
@@ -68,8 +68,8 @@ extension Subprocess {
             return .init(method: .collected(128 * 1024))
         }
 
-        public static func writeTo(_ fd: FileDescriptor, closeWhenDone: Bool) -> Self {
-            return .init(method: .fileDescriptor(fd, closeWhenDone))
+        public static func writeTo(_ fd: FileDescriptor, closeAfterProcessSpawned: Bool) -> Self {
+            return .init(method: .fileDescriptor(fd, closeAfterProcessSpawned))
         }
 
         public static func collect(limit: Int) -> Self {
@@ -104,12 +104,12 @@ extension Subprocess {
             return .init(method: .discarded)
         }
 
-        public static var redirect: Self {
+        public static var redirectToSequence: Self {
             return .init(method: .collected(128 * 1024))
         }
 
-        public static func writeTo(_ fd: FileDescriptor, closeWhenDone: Bool) -> Self {
-            return .init(method: .fileDescriptor(fd, closeWhenDone))
+        public static func writeTo(_ fd: FileDescriptor, closeAfterProcessSpawned: Bool) -> Self {
+            return .init(method: .fileDescriptor(fd, closeAfterProcessSpawned))
         }
 
         internal func createExecutionOutput() throws -> ExecutionOutput {

Sources/FoundationEssentials/Subprocess/Subprocess.swift

@@ -38,7 +38,12 @@ public struct Subprocess: Sendable {
         self.executionError = executionError
     }
 
-    public var standardOutput: AsyncBytes {
+    /// The standard output of the subprocess.
+    /// Accessing this property will **fatalError** if
+    /// - `.output` wasn't set to `.redirectToSequence` when the subprocess was spawned;
+    /// - This property was accessed multiple times. Subprocess communicates with
+    ///   parent process via pipe under the hood and each pipe can only be consumed ones.
+    public var standardOutput: some _AsyncSequence<UInt8, any Error> {
         guard let (_, fd) = self.executionOutput
             .consumeCollectedFileDescriptor() else {
             fatalError("The standard output was not redirected")
@@ -49,7 +54,12 @@ public struct Subprocess: Sendable {
         return AsyncBytes(fileDescriptor: fd)
     }
 
-    public var standardError: AsyncBytes {
+    /// The standard error of the subprocess.
+    /// Accessing this property will **fatalError** if
+    /// - `.error` wasn't set to `.redirectToSequence` when the subprocess was spawned;
+    /// - This property was accessed multiple times. Subprocess communicates with
+    ///   parent process via pipe under the hood and each pipe can only be consumed ones.
+    public var standardError: some _AsyncSequence<UInt8, any Error> {
         guard let (_, fd) = self.executionError
             .consumeCollectedFileDescriptor() else {
             fatalError("The standard error was not redirected")
@@ -101,7 +111,7 @@ extension Subprocess {
 
 // MARK: - Result
 extension Subprocess {
-    public struct Result<T: Sendable>: Sendable {
+    public struct ExecutionResult<T: Sendable>: Sendable {
         public let terminationStatus: TerminationStatus
         public let value: T
 
@@ -142,9 +152,11 @@ extension Subprocess {
     }
 }
 
-extension Subprocess.Result: Equatable where T : Equatable {}
+extension Subprocess.ExecutionResult: Equatable where T : Equatable {}
 
-extension Subprocess.Result: Hashable where T : Hashable {}
+extension Subprocess.ExecutionResult: Hashable where T : Hashable {}
+
+extension Subprocess.ExecutionResult: Codable where T : Codable {}
 
 // MARK: Internal
 extension Subprocess {

Sources/_FoundationCShims/include/_FoundationCShims.h

@@ -21,6 +21,7 @@
 #include "bplist_shims.h"
 #include "io_shims.h"
 #include "platform_shims.h"
+#include "process_shims.h"
 #include "filemanager_shims.h"
 #include "uuid.h"
 

Sources/_FoundationCShims/process_shims.c

@@ -263,13 +263,22 @@ int _subprocess_fork_exec(
     }
 
     // Bind stdin, stdout, and stderr
-    int rc = dup2(file_descriptors[0], STDIN_FILENO);
-    if (rc != 0) { return rc; }
-    rc = dup2(file_descriptors[2], STDOUT_FILENO);
-    if (rc != 0) { return rc; }
-    rc = dup2(file_descriptors[4], STDERR_FILENO);
-    if (rc != 0) { return rc; }
+    int rc = 0;
+    if (file_descriptors[0] != 0) {
+        rc = dup2(file_descriptors[0], STDIN_FILENO);
+        if (rc != 0) { return rc; }
+    }
+    if (file_descriptors[2] != 0) {
+        rc = dup2(file_descriptors[2], STDOUT_FILENO);
+        if (rc != 0) { return rc; }
+    }
+
+    if (file_descriptors[4] != 0) {
+        rc = dup2(file_descriptors[4], STDERR_FILENO);
+        if (rc != 0) { return rc; }
+    }
 
+#warning Shold close all and then return error no early return
     // Close parent side
     if (file_descriptors[1] != 0) {
         rc = close(file_descriptors[1]);