diff --git a/CHANGES b/CHANGES
index 672e2c8..79f047f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -10,6 +10,7 @@
   cleanups in stralloc and buffer:
     int -> long for sizes
     char -> unsigned char for strings
+  buffer_getline is now a function, not a macro
 
 0.20:
   add errmsg API
diff --git a/buffer/buffer_getline.c b/buffer/buffer_getline.c
new file mode 100644
index 0000000..675c184
--- /dev/null
+++ b/buffer/buffer_getline.c
@@ -0,0 +1,5 @@
+#include <buffer.h>
+
+int buffer_getline(buffer* b,unsigned char* x,unsigned long int len) {
+  return buffer_get_token(b,x,len,"\n",1);
+}
diff --git a/io.h b/io.h
index 5f3f052..505e2d8 100644
--- a/io.h
+++ b/io.h
@@ -100,6 +100,11 @@ int io_passfd(int64 sock,int64 fd);
  * process.  Return sock if ok, -1 on error, setting errno. */
 int64 io_receivefd(int64 sock);
 
+typedef int64 (*io_write_callback)(int64 s,const void* buf,uint64 n);
+
+/* used internally, but hey, who knows */
+int64 io_mmapwritefile(int64 out,int64 in,uint64 off,uint64 bytes,io_write_callback writecb);
+
 #ifdef __MINGW32__
 #include_next <io.h>
 #endif
diff --git a/io/io_sendfile.c b/io/io_sendfile.c
index 893be76..d828b9e 100644
--- a/io/io_sendfile.c
+++ b/io/io_sendfile.c
@@ -113,91 +113,14 @@ int64 io_sendfile(int64 s,int64 fd,uint64 off,uint64 n) {
 
 #else
 
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/mman.h>
+#include <iob.h>
 
-#define BUFSIZE 16384
+static int64 writecb(int64 s,const void* buf,uint64 n) {
+  return write(s,buf,n);
+}
 
 int64 io_sendfile(int64 out,int64 in,uint64 off,uint64 bytes) {
-  char buf[BUFSIZE];
-  int n,m;
-  uint64 sent=0;
-  io_entry* e=array_get(&io_fds,sizeof(io_entry),out);
-  if (e) {
-    const char* c;
-    long left;
-    do {
-      if (e->mmapped) {
-	/* did we already map the right chunk? */
-	if (off>=e->mapofs && off<e->mapofs+e->maplen)
-	  goto mapok;	/* ok; mmapped the right chunk*/
-	munmap(e->mmapped,e->maplen);
-      }
-      e->mapofs=off&0xffffffffffff0000ull;
-      if (e->mapofs+0x10000>off+bytes)
-	e->maplen=off+bytes-e->mapofs;
-      else
-	e->maplen=0x10000;
-      if ((e->mmapped=mmap(0,e->maplen,PROT_READ,MAP_SHARED,in,e->mapofs))==MAP_FAILED) {
-	e->mmapped=0;
-	goto readwrite;
-      }
-  mapok:
-      c=(const char*)(e->mmapped)+(off&0xffff);
-      left=e->maplen-(off&0xffff);
-      if (left>bytes) left=bytes;
-      while (left>0) {
-	m=write(out,c,left);
-	if (m==-1) {
-	  e->canwrite=0;
-	  e->next_write=-1;
-	  if (errno!=EAGAIN) {
-	    munmap(e->mmapped,e->maplen);
-	    e->mmapped=0;
-	    return -3;
-	  }
-	  return sent?sent:-1;
-	}
-	if (m==0) return sent;
-	sent+=m;
-	left-=m;
-	bytes-=m;
-	off+=m;
-	c+=m;
-      }
-    } while (bytes);
-    if (e->mmapped) {
-      munmap(e->mmapped,e->maplen);
-      e->mmapped=0;
-    }
-    return sent;
-  }
-readwrite:
-  if (lseek(in,off,SEEK_SET) != off)
-    return -1;
-  while (bytes>0) {
-    char* tmp=buf;
-    if ((n=read(in,tmp,(bytes<BUFSIZE)?bytes:BUFSIZE))<=0)
-      return (sent?sent:-1);
-    while (n>0) {
-      if ((m=write(out,tmp,n))<0) {
-	if (m==-1) {
-	  if (e) {
-	    e->canwrite=0;
-	    e->next_write=-1;
-	  }
-	  return errno==EAGAIN?(sent?sent:-1):-3;
-	}
-	goto abort;
-      }
-      sent+=m;
-      n-=m;
-      tmp+=m;
-    }
-  }
-abort:
-  return sent;
+  return io_mmapwritefile(out,in,off,bytes,writecb);
 }
 
 #endif
diff --git a/io/iob_addfile.c b/io/iob_addfile.c
index d57784a..dead5a2 100644
--- a/io/iob_addfile.c
+++ b/io/iob_addfile.c
@@ -3,6 +3,7 @@
 int iob_addfile(io_batch* b,int64 fd,uint64 off,uint64 n) {
   iob_entry* e;
   if (n==0) return 1;
+  io_fd(fd);
   e=array_allocate(&b->b,sizeof(iob_entry),
 			     array_length(&b->b,sizeof(iob_entry)));
   if (!e) return 0;
diff --git a/io/iob_addfile_close.c b/io/iob_addfile_close.c
index d8ae66a..3aa65d9 100644
--- a/io/iob_addfile_close.c
+++ b/io/iob_addfile_close.c
@@ -3,6 +3,7 @@
 int iob_addfile_close(io_batch* b,int64 fd,uint64 off,uint64 n) {
   iob_entry* e;
   if (n==0) return 1;
+  io_fd(fd);
   e=array_allocate(&b->b,sizeof(iob_entry),
 		   array_length(&b->b,sizeof(iob_entry)));
   if (!e) return 0;
diff --git a/io/iob_send.c b/io/iob_send.c
index d796f95..94faca0 100644
--- a/io/iob_send.c
+++ b/io/iob_send.c
@@ -1,8 +1,4 @@
 #include "havebsdsf.h"
-#ifdef HAVE_BSDSENDFILE
-/* for MacOS X.  Yep, they blew it again. */
-#define SENDFILE 1
-#endif
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
diff --git a/iob.h b/iob.h
index 61e284e..9d9565c 100644
--- a/iob.h
+++ b/iob.h
@@ -29,6 +29,7 @@ int iob_adds_free(io_batch* b,const char* s);
 int iob_addfile(io_batch* b,int64 fd,uint64 off,uint64 n);
 int iob_addfile_close(io_batch* b,int64 fd,uint64 off,uint64 n);
 int64 iob_send(int64 s,io_batch* b);
+int64 iob_write(int64 s,io_batch* b,io_write_callback cb);
 void iob_reset(io_batch* b);
 void iob_prefetch(io_batch* b,uint64 bytes);
 
diff --git a/test/iob.c b/test/iob.c
index c2dc9ac..58b603c 100644
--- a/test/iob.c
+++ b/test/iob.c
@@ -1,17 +1,24 @@
 #include <assert.h>
 #include "iob.h"
 #include "buffer.h"
+#include <unistd.h>
+
+static int64 write_cb(int64 fd,const void* buf,uint64 len) {
+  if (len>2) len=2;
+  return write(fd,buf,len);
+}
 
 int main() {
   int64 fd;
   io_batch* b;
+  int64 r;
   assert(io_readfile(&fd,"GNUmakefile"));
   assert(b=iob_new(10));
   assert(iob_addbuf(b,"Huhu",4));
   assert(iob_addbuf(b," fnord\n",7));
   assert(iob_addfile(b,fd,10,10));
-  buffer_puts(buffer_2,"iob_send returned ");
-  buffer_putlong(buffer_2,iob_send(1,b));
-  buffer_putsflush(buffer_2,".\n");
+  do {
+    r=iob_write(1,b,write_cb);
+  } while (r>0);
   return 0;
 }