Make Configuration.workingDirectory optional

Sources/Subprocess/Configuration.swift

@@ -39,7 +39,8 @@ public struct Configuration: Sendable {
     /// The environment to use when running the executable.
     public var environment: Environment
     /// The working directory to use when running the executable.
-    public var workingDirectory: FilePath
+    /// If this property is `nil`, the subprocess will inherit the working directory from the parent process.
+    public var workingDirectory: FilePath?
     /// The platform specific options to use when
     /// running the subprocess.
     public var platformOptions: PlatformOptions
@@ -54,7 +55,7 @@ public struct Configuration: Sendable {
         self.executable = executable
         self.arguments = arguments
         self.environment = environment
-        self.workingDirectory = workingDirectory ?? .currentWorkingDirectory
+        self.workingDirectory = workingDirectory
         self.platformOptions = platformOptions
     }
 
@@ -107,7 +108,7 @@ extension Configuration: CustomStringConvertible, CustomDebugStringConvertible {
                 executable: \(self.executable.description),
                 arguments: \(self.arguments.description),
                 environment: \(self.environment.description),
-                workingDirectory: \(self.workingDirectory),
+                workingDirectory: \(self.workingDirectory?.string ?? ""),
                 platformOptions: \(self.platformOptions.description(withIndent: 1))
             )
             """
@@ -119,7 +120,7 @@ extension Configuration: CustomStringConvertible, CustomDebugStringConvertible {
                 executable: \(self.executable.debugDescription),
                 arguments: \(self.arguments.debugDescription),
                 environment: \(self.environment.debugDescription),
-                workingDirectory: \(self.workingDirectory),
+                workingDirectory: \(self.workingDirectory?.string ?? ""),
                 platformOptions: \(self.platformOptions.description(withIndent: 1))
             )
             """
@@ -714,14 +715,6 @@ internal struct CreatedPipe: ~Copyable {
     }
 }
 
-extension FilePath {
-    static var currentWorkingDirectory: Self {
-        let path = getcwd(nil, 0)!
-        defer { free(path) }
-        return .init(String(cString: path))
-    }
-}
-
 extension Optional where Wrapped: Collection {
     func withOptionalUnsafeBufferPointer<Result>(
         _ body: ((UnsafeBufferPointer<Wrapped.Element>)?) throws -> Result

Sources/Subprocess/Platforms/Subprocess+Darwin.swift

@@ -349,9 +349,13 @@ extension Configuration {
                 }
 
                 // Setup cwd
-                let intendedWorkingDir = self.workingDirectory.string
-                let chdirError: Int32 = intendedWorkingDir.withPlatformString { workDir in
-                    return posix_spawn_file_actions_addchdir_np(&fileActions, workDir)
+                let chdirError: Int32
+                if let intendedWorkingDir = self.workingDirectory?.string {
+                    chdirError = intendedWorkingDir.withPlatformString { workDir in
+                        return posix_spawn_file_actions_addchdir_np(&fileActions, workDir)
+                    }
+                } else {
+                    chdirError = 0
                 }
 
                 // Error handling
@@ -457,12 +461,13 @@ extension Configuration {
                 errorRead: errorReadFileDescriptor,
                 errorWrite: errorWriteFileDescriptor
             )
-            let workingDirectory = self.workingDirectory.string
-            guard Configuration.pathAccessible(workingDirectory, mode: F_OK) else {
-                throw SubprocessError(
-                    code: .init(.failedToChangeWorkingDirectory(workingDirectory)),
-                    underlyingError: .init(rawValue: ENOENT)
-                )
+            if let workingDirectory = self.workingDirectory?.string {
+                guard Configuration.pathAccessible(workingDirectory, mode: F_OK) else {
+                    throw SubprocessError(
+                        code: .init(.failedToChangeWorkingDirectory(workingDirectory)),
+                        underlyingError: .init(rawValue: ENOENT)
+                    )
+                }
             }
             throw SubprocessError(
                 code: .init(.executableNotFound(self.executable.description)),

Sources/Subprocess/Platforms/Subprocess+Linux.swift

@@ -85,11 +85,10 @@ extension Configuration {
                     errorReadFileDescriptor?.platformDescriptor() ?? -1,
                 ]
 
-                let workingDirectory: String = self.workingDirectory.string
                 // Spawn
                 var pid: pid_t = 0
                 let spawnError: CInt = possibleExecutablePath.withCString { exePath in
-                    return workingDirectory.withCString { workingDir in
+                    return (self.workingDirectory?.string).withOptionalCString { workingDir in
                         return supplementaryGroups.withOptionalUnsafeBufferPointer { sgroups in
                             return fileDescriptors.withUnsafeBufferPointer { fds in
                                 return _subprocess_fork_exec(
@@ -173,12 +172,13 @@ extension Configuration {
                 errorRead: errorReadFileDescriptor,
                 errorWrite: errorWriteFileDescriptor
             )
-            let workingDirectory = self.workingDirectory.string
-            guard Configuration.pathAccessible(workingDirectory, mode: F_OK) else {
-                throw SubprocessError(
-                    code: .init(.failedToChangeWorkingDirectory(workingDirectory)),
-                    underlyingError: .init(rawValue: ENOENT)
-                )
+            if let workingDirectory = self.workingDirectory?.string {
+                guard Configuration.pathAccessible(workingDirectory, mode: F_OK) else {
+                    throw SubprocessError(
+                        code: .init(.failedToChangeWorkingDirectory(workingDirectory)),
+                        underlyingError: .init(rawValue: ENOENT)
+                    )
+                }
             }
             throw SubprocessError(
                 code: .init(.executableNotFound(self.executable.description)),

Sources/Subprocess/Platforms/Subprocess+Windows.swift

@@ -84,7 +84,7 @@ extension Configuration {
                 try environment.withCString(
                     encodedAs: UTF16.self
                 ) { environmentW in
-                    try intendedWorkingDir.withNTPathRepresentation { intendedWorkingDirW in
+                    try intendedWorkingDir.withOptionalNTPathRepresentation { intendedWorkingDirW in
                         let created = CreateProcessW(
                             applicationNameW,
                             UnsafeMutablePointer<WCHAR>(mutating: commandAndArgsW),
@@ -223,7 +223,7 @@ extension Configuration {
                             try environment.withCString(
                                 encodedAs: UTF16.self
                             ) { environmentW in
-                                try intendedWorkingDir.withNTPathRepresentation { intendedWorkingDirW in
+                                try intendedWorkingDir.withOptionalNTPathRepresentation { intendedWorkingDirW in
                                     let created = CreateProcessWithLogonW(
                                         usernameW,
                                         domainW,
@@ -769,7 +769,7 @@ extension Configuration {
         applicationName: String?,
         commandAndArgs: String,
         environment: String,
-        intendedWorkingDir: String
+        intendedWorkingDir: String?
     ) {
         // Prepare environment
         var env: [String: String] = [:]
@@ -806,19 +806,21 @@ extension Configuration {
             commandAndArgs
         ) = try self.generateWindowsCommandAndAgruments()
         // Validate workingDir
-        guard Self.pathAccessible(self.workingDirectory.string) else {
-            throw SubprocessError(
-                code: .init(
-                    .failedToChangeWorkingDirectory(self.workingDirectory.string)
-                ),
-                underlyingError: nil
-            )
+        if let workingDirectory = self.workingDirectory?.string {
+            guard Self.pathAccessible(workingDirectory) else {
+                throw SubprocessError(
+                    code: .init(
+                        .failedToChangeWorkingDirectory(workingDirectory)
+                    ),
+                    underlyingError: nil
+                )
+            }
         }
         return (
             applicationName: applicationName,
             commandAndArgs: commandAndArgs,
             environment: environmentString,
-            intendedWorkingDir: self.workingDirectory.string
+            intendedWorkingDir: self.workingDirectory?.string
         )
     }
 

Sources/_SubprocessCShims/process_shims.c

@@ -397,9 +397,11 @@ static int _subprocess_posix_spawn_fallback(
         if (rc != 0) { return rc; }
     }
     // Setup working directory
-    rc = _subprocess_addchdir_np(&file_actions, working_directory);
-    if (rc != 0) {
-        return rc;
+    if (working_directory != NULL) {
+        rc = _subprocess_addchdir_np(&file_actions, working_directory);
+        if (rc != 0) {
+            return rc;
+        }
     }
 
     // Close parent side