1 files changed, 54 insertions, 0 deletions
diff --git a/archival/libarchive/open_transformer.c b/archival/libarchive/open_transformer.c
new file mode 100644
index 000000000..26ae565f5
--- /dev/null
+++ b/archival/libarchive/open_transformer.c
@@ -0,0 +1,54 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+#include "libbb.h"
+#include "archive.h"
+
+/* transformer(), more than meets the eye */
+/*
+ * On MMU machine, the transform_prog is removed by macro magic
+ * in include/archive.h. On NOMMU, transformer is removed.
+ */
+void FAST_FUNC open_transformer(int fd,
+	IF_DESKTOP(long long) int FAST_FUNC (*transformer)(int src_fd, int dst_fd),
+	const char *transform_prog)
+{
+	struct fd_pair fd_pipe;
+	int pid;
+
+	xpiped_pair(fd_pipe);
+	pid = BB_MMU ? xfork() : xvfork();
+	if (pid == 0) {
+		/* Child */
+		close(fd_pipe.rd); /* we don't want to read from the parent */
+		// FIXME: error check?
+#if BB_MMU
+		transformer(fd, fd_pipe.wr);
+		if (ENABLE_FEATURE_CLEAN_UP) {
+			close(fd_pipe.wr); /* send EOF */
+			close(fd);
+		}
+		/* must be _exit! bug was actually seen here */
+		_exit(EXIT_SUCCESS);
+#else
+		{
+			char *argv[4];
+			xmove_fd(fd, 0);
+			xmove_fd(fd_pipe.wr, 1);
+			argv[0] = (char*)transform_prog;
+			argv[1] = (char*)"-cf";
+			argv[2] = (char*)"-";
+			argv[3] = NULL;
+			BB_EXECVP(transform_prog, argv);
+			bb_perror_msg_and_die("can't execute '%s'", transform_prog);
+		}
+#endif
+		/* notreached */
+	}
+
+	/* parent process */
+	close(fd_pipe.wr); /* don't want to write to the child */
+	xmove_fd(fd_pipe.rd, fd);
+}