Revert "Use SocketPair"

This reverts commit 5077225.

Author: finestructure

Sources/ShellOut.swift

@@ -453,10 +453,9 @@ private extension Process {
             self.environment = environment
         }
 
-        let outputPipe = SocketPair()
-        let errorPipe = SocketPair()
-        self.standardOutput = outputPipe.fileHandleForWriting
-        self.standardError = errorPipe.fileHandleForWriting
+        let outputPipe = Pipe(), errorPipe = Pipe()
+        self.standardOutput = outputPipe
+        self.standardError = errorPipe
 
         // Because FileHandle's readabilityHandler might be called from a
         // different queue from the calling queue, avoid data races by
@@ -655,30 +654,3 @@ private extension String {
         self = appending(arguments: arguments)
     }
 }
-
-
-final class SocketPair {
-    let fileHandleForReading: FileHandle
-    let fileHandleForWriting: FileHandle
-
-    init() {
-        let fds = UnsafeMutablePointer<Int32>.allocate(capacity: 2)
-        defer { fds.deallocate() }
-
-#if os(macOS)
-        let ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds)
-#else
-        let ret = socketpair(AF_UNIX, Int32(SOCK_STREAM.rawValue), 0, fds)
-#endif
-        switch (ret, errno) {
-        case (0, _):
-            self.fileHandleForReading = FileHandle(fileDescriptor: fds.pointee, closeOnDealloc: true)
-            self.fileHandleForWriting = FileHandle(fileDescriptor: fds.successor().pointee, closeOnDealloc: true)
-        case (-1, EMFILE), (-1, ENFILE):
-            self.fileHandleForReading = FileHandle(fileDescriptor: -1, closeOnDealloc: false)
-            self.fileHandleForWriting = FileHandle(fileDescriptor: -1, closeOnDealloc: false)
-        default:
-            fatalError("Error calling socketpair(): \(errno)")
-        }
-    }
-}