diff --git a/CHANGES b/CHANGES
index 4a2a3f1..d97da7b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,9 @@
   add API for integer multiply with overflow detection
   change length counters from int to long for 64-bit platforms
   add array API from http://cr.yp.to/lib/array.html
+  oops, had a declaration and man page for taia_addsec but not the
+    function itself
+  add buffer functions to write strerror(errno)
 
 0.15:
   man page update (document stralloc return values)
diff --git a/array.h b/array.h
index 0afbdc9..9241524 100644
--- a/array.h
+++ b/array.h
@@ -32,6 +32,6 @@ void array_cat0(array* to);
 void array_cate(array* to,const array* const from,int64 pos,int64 stop);
 
 #define array_failed(x) (array_bytes(x)==-1)
-#define array_allocated(x) (array_bytes(x)==0)
+#define array_unallocated(x) (array_bytes(x)==0)
 
 #endif
diff --git a/buffer.h b/buffer.h
index 04721e2..f0f7a0e 100644
--- a/buffer.h
+++ b/buffer.h
@@ -15,18 +15,18 @@ typedef struct buffer {
 #define BUFFER_INSIZE 8192
 #define BUFFER_OUTSIZE 8192
 
-extern void buffer_init(buffer* b,int (*op)(),int fd,char* y,unsigned int ylen);
+void buffer_init(buffer* b,int (*op)(),int fd,char* y,unsigned int ylen);
 
-extern int buffer_flush(buffer* b);
-extern int buffer_put(buffer* b,const char* x,unsigned int len);
-extern int buffer_putalign(buffer* b,const char* x,unsigned int len);
-extern int buffer_putflush(buffer* b,const char* x,unsigned int len);
-extern int buffer_puts(buffer* b,const char* x);
-extern int buffer_putsalign(buffer* b,const char* x);
-extern int buffer_putsflush(buffer* b,const char* x);
+int buffer_flush(buffer* b);
+int buffer_put(buffer* b,const char* x,unsigned int len);
+int buffer_putalign(buffer* b,const char* x,unsigned int len);
+int buffer_putflush(buffer* b,const char* x,unsigned int len);
+int buffer_puts(buffer* b,const char* x);
+int buffer_putsalign(buffer* b,const char* x);
+int buffer_putsflush(buffer* b,const char* x);
 
-extern int buffer_putspace(buffer* b);
-extern int buffer_putnlflush(buffer* b); /* put \n and flush */
+int buffer_putspace(buffer* b);
+int buffer_putnlflush(buffer* b); /* put \n and flush */
 
 #define buffer_PUTC(s,c) \
   ( ((s)->a != (s)->p) \
@@ -34,16 +34,16 @@ extern int buffer_putnlflush(buffer* b); /* put \n and flush */
     : buffer_put((s),&(c),1) \
   )
 
-extern int buffer_get(buffer* b,char* x,unsigned int len);
-extern int buffer_feed(buffer* b);
-extern int buffer_getc(buffer* b,char* x);
-extern int buffer_getn(buffer* b,char* x,unsigned int len);
+int buffer_get(buffer* b,char* x,unsigned int len);
+int buffer_feed(buffer* b);
+int buffer_getc(buffer* b,char* x);
+int buffer_getn(buffer* b,char* x,unsigned int len);
 
 /* read bytes until the destination buffer is full (len bytes), end of
  * file is reached or the read char is in charset (setlen bytes).  An
  * empty line when looking for \n will write '\n' to x and return 0.  If
  * EOF is reached, \0 is written to the buffer */
-extern int buffer_get_token(buffer* b,char* x,unsigned int len,const char* charset,unsigned int setlen);
+int buffer_get_token(buffer* b,char* x,unsigned int len,const char* charset,unsigned int setlen);
 #define buffer_getline(b,x,len) buffer_get_token((b),(x),(len),"\n",1)
 
 /* this predicate is given the string as currently read from the buffer
@@ -51,10 +51,10 @@ extern int buffer_get_token(buffer* b,char* x,unsigned int len,const char* chars
 typedef int (*string_predicate)(const char* x,unsigned int len);
 
 /* like buffer_get_token but the token ends when your predicate says so */
-extern int buffer_get_token_pred(buffer* b,char* x,unsigned int len,string_predicate p);
+int buffer_get_token_pred(buffer* b,char* x,unsigned int len,string_predicate p);
 
-extern char *buffer_peek(buffer* b);
-extern void buffer_seek(buffer* b,unsigned int len);
+char *buffer_peek(buffer* b);
+void buffer_seek(buffer* b,unsigned int len);
 
 #define buffer_PEEK(s) ( (s)->x + (s)->p )
 #define buffer_SEEK(s,len) ( (s)->p += (len) )
@@ -65,22 +65,28 @@ extern void buffer_seek(buffer* b,unsigned int len);
     : buffer_get((s),(c),1) \
   )
 
-extern int buffer_copy(buffer* out,buffer* in);
+int buffer_copy(buffer* out,buffer* in);
 
-extern int buffer_putulong(buffer *b,unsigned long l);
-extern int buffer_put8long(buffer *b,unsigned long l);
-extern int buffer_putxlong(buffer *b,unsigned long l);
-extern int buffer_putlong(buffer *b,unsigned long l);
+int buffer_putulong(buffer *b,unsigned long l);
+int buffer_put8long(buffer *b,unsigned long l);
+int buffer_putxlong(buffer *b,unsigned long l);
+int buffer_putlong(buffer *b,signed long l);
 
-extern buffer *buffer_0;
-extern buffer *buffer_0small;
-extern buffer *buffer_1;
-extern buffer *buffer_1small;
-extern buffer *buffer_2;
+int buffer_putlonglong(buffer* b,signed long long l);
+int buffer_putulonglong(buffer* b,unsigned long long l);
+
+int buffer_puterror(buffer* b);
+int buffer_puterror2(buffer* b, int errnum);
+
+buffer *buffer_0;
+buffer *buffer_0small;
+buffer *buffer_1;
+buffer *buffer_1small;
+buffer *buffer_2;
 
 #ifdef STRALLOC_H
 /* write stralloc to buffer */
-extern int buffer_putsa(buffer* b,stralloc* sa);
+int buffer_putsa(buffer* b,stralloc* sa);
 
 /* these "read token" functions return 0 if the token was complete or
  * EOF was hit or -1 on error.  In contrast to the non-stralloc token
@@ -94,14 +100,14 @@ extern int buffer_putsa(buffer* b,stralloc* sa);
  * data is available. */
 
 /* read token from buffer to stralloc */
-extern int buffer_get_token_sa(buffer* b,stralloc* sa,const char* charset,unsigned int setlen);
+int buffer_get_token_sa(buffer* b,stralloc* sa,const char* charset,unsigned int setlen);
 /* read line from buffer to stralloc */
-extern int buffer_getline_sa(buffer* b,stralloc* sa);
+int buffer_getline_sa(buffer* b,stralloc* sa);
 
 typedef int (*sa_predicate)(stralloc* sa);
 
 /* like buffer_get_token_sa but the token ends when your predicate says so */
-extern int buffer_get_token_sa_pred(buffer* b,stralloc* sa,sa_predicate p);
+int buffer_get_token_sa_pred(buffer* b,stralloc* sa,sa_predicate p);
 
 /* make a buffer from a stralloc.
  * Do not change the stralloc after this! */
diff --git a/buffer/buffer_puterror.3 b/buffer/buffer_puterror.3
new file mode 100644
index 0000000..a679537
--- /dev/null
+++ b/buffer/buffer_puterror.3
@@ -0,0 +1,11 @@
+.TH buffer_puterror 3
+.SH NAME
+buffer_puterror \- write error string to buffer and flush
+.SH SYNTAX
+.B #include <buffer.h>
+
+int \fBbuffer_puterror\fP(buffer* \fIb\fR);
+.SH DESCRIPTION
+buffer_puterror is equivalent to calling buffer_puterror2 with errno.
+.SH "SEE ALSO"
+buffer_puterror2(3), buffer_puts(3), buffer_put(3), buffer_flush(3), buffer(3)
diff --git a/buffer/buffer_puterror.c b/buffer/buffer_puterror.c
new file mode 100644
index 0000000..35384ea
--- /dev/null
+++ b/buffer/buffer_puterror.c
@@ -0,0 +1,7 @@
+#include "buffer.h"
+#include <string.h>
+#include <errno.h>
+
+int buffer_puterror(buffer* b) {
+  return buffer_puts(b,strerror(errno));
+}
diff --git a/buffer/buffer_puterror2.3 b/buffer/buffer_puterror2.3
new file mode 100644
index 0000000..3e0996d
--- /dev/null
+++ b/buffer/buffer_puterror2.3
@@ -0,0 +1,13 @@
+.TH buffer_puterror2 3
+.SH NAME
+buffer_puterror2 \- write error string to buffer and flush
+.SH SYNTAX
+.B #include <buffer.h>
+
+int \fBbuffer_puterror2\fP(buffer* \fIb\fR,int \fIerrnum\fR);
+.SH DESCRIPTION
+buffer_puterror2 writes the error message corresponding to the error
+number in \fIerrnum\fR to the buffer (e.g. "No such file or directory"
+for ENOENT).
+.SH "SEE ALSO"
+buffer_puterror(3), buffer_puts(3), buffer_put(3), buffer_flush(3), buffer(3)
diff --git a/buffer/buffer_puterror2.c b/buffer/buffer_puterror2.c
new file mode 100644
index 0000000..b8fb956
--- /dev/null
+++ b/buffer/buffer_puterror2.c
@@ -0,0 +1,6 @@
+#include "buffer.h"
+#include <string.h>
+
+int buffer_puterror2(buffer* b,int errnum) {
+  return buffer_puts(b,strerror(errnum));
+}
diff --git a/buffer/buffer_putlong.3 b/buffer/buffer_putlong.3
index a4b7b9d..9e2e688 100644
--- a/buffer/buffer_putlong.3
+++ b/buffer/buffer_putlong.3
@@ -5,7 +5,7 @@ long integer to buffer
 .SH SYNTAX
 .B #include <buffer.h>
 
-int \fBbuffer_putlong\fP(buffer* \fIb\fR,unsigned long \fIx\fR);
+int \fBbuffer_putlong\fP(buffer* \fIb\fR,signed long \fIx\fR);
 .SH DESCRIPTION
 buffer_putlong is similar to passing the result of fmt_long to
 buffer_put.
diff --git a/buffer/buffer_putlong.c b/buffer/buffer_putlong.c
index 1d11527..c622f34 100644
--- a/buffer/buffer_putlong.c
+++ b/buffer/buffer_putlong.c
@@ -1,8 +1,8 @@
 #include "buffer.h"
 #include "fmt.h"
 
-int buffer_putlong(buffer *b,unsigned long l) {
-  char buf[FMT_ULONG];
+int buffer_putlong(buffer *b,signed long l) {
+  char buf[FMT_LONG];
   return buffer_put(b,buf,fmt_long(buf,l));
 }
 
diff --git a/buffer/buffer_putlonglong.3 b/buffer/buffer_putlonglong.3
new file mode 100644
index 0000000..d0fff3b
--- /dev/null
+++ b/buffer/buffer_putlonglong.3
@@ -0,0 +1,13 @@
+.TH buffer_putlonglong 3
+.SH NAME
+buffer_putlonglong \- write a decimal ASCII representation of a signed
+long integer to buffer
+.SH SYNTAX
+.B #include <buffer.h>
+
+int \fBbuffer_putlonglong\fP(buffer* \fIb\fR,signed long long \fIx\fR);
+.SH DESCRIPTION
+buffer_putlonglong is equivalent to passing the result of fmt_longlong to
+buffer_put.
+.SH "SEE ALSO"
+fmt_longlong(3), buffer_put(3), buffer_flush(3), buffer(3)
diff --git a/buffer/buffer_putlonglong.c b/buffer/buffer_putlonglong.c
new file mode 100644
index 0000000..efbcbfe
--- /dev/null
+++ b/buffer/buffer_putlonglong.c
@@ -0,0 +1,8 @@
+#include "buffer.h"
+#include "fmt.h"
+
+int buffer_putlonglong(buffer *b,signed long long l) {
+  char buf[FMT_LONG];
+  return buffer_put(b,buf,fmt_longlong(buf,l));
+}
+
diff --git a/buffer/buffer_putulonglong.3 b/buffer/buffer_putulonglong.3
new file mode 100644
index 0000000..3c7c387
--- /dev/null
+++ b/buffer/buffer_putulonglong.3
@@ -0,0 +1,13 @@
+.TH buffer_putulonglong 3
+.SH NAME
+buffer_putulonglong \- write a decimal ASCII representation of a signed
+long integer to buffer
+.SH SYNTAX
+.B #include <buffer.h>
+
+int \fBbuffer_putulonglong\fP(buffer* \fIb\fR,unsigned long long \fIx\fR);
+.SH DESCRIPTION
+buffer_putulonglong is equivalent to passing the result of fmt_ulonglong to
+buffer_put.
+.SH "SEE ALSO"
+fmt_ulonglong(3), buffer_put(3), buffer_flush(3), buffer(3)
diff --git a/buffer/buffer_putulonglong.c b/buffer/buffer_putulonglong.c
new file mode 100644
index 0000000..861acf5
--- /dev/null
+++ b/buffer/buffer_putulonglong.c
@@ -0,0 +1,8 @@
+#include "buffer.h"
+#include "fmt.h"
+
+int buffer_putulonglong(buffer *b,unsigned long long l) {
+  char buf[FMT_ULONG];
+  return buffer_put(b,buf,fmt_ulonglong(buf,l));
+}
+
diff --git a/io.h b/io.h
index 327fe8a..0d96388 100644
--- a/io.h
+++ b/io.h
@@ -26,7 +26,7 @@ int64 io_trywrite(int64 d,const char* buf,int64 len);
 int64 io_waitwrite(int64 d,const char* buf,int64 len);
 
 /* modify timeout attribute of file descriptor */
-void io_timeout(int64 d,struct taia t);
+void io_timeout(int64 d,tai6464 t);
 
 /* like io_tryread but will return -2,errno=ETIMEDOUT if d has a timeout
  * associated and it is passed without input being there */
@@ -42,7 +42,7 @@ void io_dontwantread(int64 d);
 void io_dontwantwrite(int64 d);
 
 void io_wait();
-void io_waituntil(struct taia t);
+void io_waituntil(tai6464 t);
 void io_check();
 
 /* return next descriptor from io_wait that can be read from */
diff --git a/io/io_timeout.c b/io/io_timeout.c
new file mode 100644
index 0000000..b1415f8
--- /dev/null
+++ b/io/io_timeout.c
@@ -0,0 +1,7 @@
+#include "io_internal.h"
+
+void io_timeout(int64 d,tai6464 t) {
+  io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
+  if (e)
+    e->timeout=t;
+}
diff --git a/io/io_tryreadtimeout.c b/io/io_tryreadtimeout.c
new file mode 100644
index 0000000..5c41bcb
--- /dev/null
+++ b/io/io_tryreadtimeout.c
@@ -0,0 +1,19 @@
+#include <unistd.h>
+#include <sys/time.h>
+#include <poll.h>
+#include <errno.h>
+#include "io_internal.h"
+
+int64 io_tryreadtimeout(int64 d,char* buf,int64 len) {
+  int64 r=io_tryread(d,buf,len);
+  if (r==-1) {
+    tai6464 x;
+    io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
+    taia_now(&x);
+    if (taia_less(&x,&e->timeout)) {
+      errno=ETIMEDOUT;
+      r=-2;
+    }
+  }
+  return r;
+}
diff --git a/io/io_trywritetimeout.c b/io/io_trywritetimeout.c
new file mode 100644
index 0000000..75b4894
--- /dev/null
+++ b/io/io_trywritetimeout.c
@@ -0,0 +1,19 @@
+#include <unistd.h>
+#include <sys/time.h>
+#include <poll.h>
+#include <errno.h>
+#include "io_internal.h"
+
+int64 io_trywritetimeout(int64 d,const char* buf,int64 len) {
+  int64 r=io_trywrite(d,buf,len);
+  if (r==-1) {
+    tai6464 x;
+    io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
+    taia_now(&x);
+    if (taia_less(&x,&e->timeout)) {
+      errno=ETIMEDOUT;
+      r=-2;
+    }
+  }
+  return r;
+}
diff --git a/io/io_waitread.c b/io/io_waitread.c
new file mode 100644
index 0000000..f89eb6f
--- /dev/null
+++ b/io/io_waitread.c
@@ -0,0 +1,27 @@
+#include <unistd.h>
+#include <poll.h>
+#include <errno.h>
+#include "io_internal.h"
+
+int64 io_waitread(int64 d,char* buf,int64 len) {
+  long r;
+  struct pollfd p;
+  io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
+  if (!e) { errno=EBADF; return -3; }
+  if (e->nonblock) {
+again:
+    p.fd=d;
+    if (p.fd != d) { errno=EBADF; return -3; }	/* catch overflow */
+    p.events=POLLIN;
+    switch (poll(&p,1,-1)) {
+    case -1: if (errno==EAGAIN) goto again; return -3;
+    }
+  }
+  r=read(d,buf,len);
+  if (r==-1) {
+    if (errno==EAGAIN)
+      goto again;
+    r=-3;
+  }
+  return r;
+}
diff --git a/io/io_waitwrite.c b/io/io_waitwrite.c
new file mode 100644
index 0000000..6c434c6
--- /dev/null
+++ b/io/io_waitwrite.c
@@ -0,0 +1,27 @@
+#include <unistd.h>
+#include <poll.h>
+#include <errno.h>
+#include "io_internal.h"
+
+int64 io_waitwrite(int64 d,const char* buf,int64 len) {
+  long r;
+  struct pollfd p;
+  io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
+  if (!e) { errno=EBADF; return -3; }
+  if (e->nonblock) {
+again:
+    p.fd=d;
+    if (p.fd != d) { errno=EBADF; return -3; }	/* catch overflow */
+    p.events=POLLOUT;
+    switch (poll(&p,1,-1)) {
+    case -1: if (errno==EAGAIN) goto again; return -3;
+    }
+  }
+  r=write(d,buf,len);
+  if (r==-1) {
+    if (errno==EAGAIN)
+      goto again;
+    r=-3;
+  }
+  return r;
+}
diff --git a/io_internal.h b/io_internal.h
index 768e97e..89babfc 100644
--- a/io_internal.h
+++ b/io_internal.h
@@ -8,6 +8,7 @@ typedef struct {
   unsigned int canwrite:1;
   unsigned int nonblock:1;
   unsigned int inuse:1;
+  tai6464 timeout;
 } io_entry;
 
 array io_fds;
diff --git a/tai.h b/tai.h
index 7c07387..17c8279 100644
--- a/tai.h
+++ b/tai.h
@@ -17,9 +17,9 @@
  * difference between two TAI64 labels.
  * See http://cr.yp.to/libtai/tai64.html */
 
-struct tai {
+typedef struct tai {
   uint64 x;
-} ;
+} tai64;
 
 
 #define tai_unix(t,u) ((void) ((t)->x = 4611686018427387914ULL + (uint64) (u)))
diff --git a/taia.h b/taia.h
index fc0e98d..3c14a0b 100644
--- a/taia.h
+++ b/taia.h
@@ -9,37 +9,37 @@
  * exclusive. The number is a multiple of 10^-18. The format of struct
  * taia is designed to speed up common operations; applications should
  * not look inside struct taia. */
-struct taia {
+typedef struct taia {
   struct tai sec;
   unsigned long nano; /* 0...999999999 */
   unsigned long atto; /* 0...999999999 */
-};
+} tai6464;
 
 /* extract seconds */
-extern void taia_tai(const struct taia *source,struct tai *dest);
+void taia_tai(const tai6464 *source,tai64 *dest);
 
 /* get current time */
-extern void taia_now(struct taia *);
+void taia_now(struct taia *);
 
 /* return double-precision approximation; always nonnegative */
-extern double taia_approx(const struct taia *);
+double taia_approx(const tai6464 *);
 /* return double-precision approximation of the fraction part;
  * always nonnegative */
-extern double taia_frac(const struct taia *);
+double taia_frac(const tai6464 *);
 
 /* add source1 to source2 modulo 2^64 and put the result in dest.
  * The inputs and output may overlap */
-extern void taia_add(struct taia *dest,const struct taia *source1,const struct taia *source2);
+void taia_add(tai6464 *dest,const tai6464 *source1,const tai6464 *source2);
 /* add secs seconds to source modulo 2^64 and put the result in dest. */
-extern void taia_addsec(struct taia *dest,const struct taia *source,int secs);
+void taia_addsec(tai6464 *dest,const tai6464 *source,long secs);
 /* subtract source2 from source1 modulo 2^64 and put the result in dest.
  * The inputs and output may overlap */
-extern void taia_sub(struct taia *,const struct taia *,const struct taia *);
+void taia_sub(tai6464 *,const tai6464 *,const tai6464 *);
 /* divide source by 2, rouding down to a multiple of 10^-18, and put the
  * result into dest.  The input and output may overlap */
-extern void taia_half(struct taia *dest,const struct taia *source);
+void taia_half(tai6464 *dest,const tai6464 *source);
 /* return 1 if a is less than b, 0 otherwise */
-extern int taia_less(const struct taia *a,const struct taia *b);
+int taia_less(const tai6464 *a,const tai6464 *b);
 
 #define TAIA_PACK 16
 /* char buf[TAIA_PACK] can be used to store a TAI64NA label in external
@@ -49,10 +49,10 @@ extern int taia_less(const struct taia *a,const struct taia *b);
 
 /* convert a TAI64NA label from internal format in src to external
  * TAI64NA format in buf. */
-extern void taia_pack(char *buf,const struct taia *src);
+void taia_pack(char *buf,const tai6464 *src);
 /* convert a TAI64NA label from external TAI64NA format in buf to
  * internal format in dest. */
-extern void taia_unpack(const char *buf,struct taia *dest);
+void taia_unpack(const char *buf,tai6464 *dest);
 
 #define TAIA_FMTFRAC 19
 /* print the 18-digit fraction part of t in decimal, without a decimal
@@ -60,9 +60,9 @@ extern void taia_unpack(const char *buf,struct taia *dest);
  * terminating \0. It returns 18, the number of characters written. s
  * may be zero; then taia_fmtfrac returns 18 without printing anything.
  * */
-extern unsigned int taia_fmtfrac(char *s,const struct taia *t);
+unsigned int taia_fmtfrac(char *s,const tai6464 *t);
 
 /* initialize t to secs seconds. */
-extern void taia_uint(struct taia *t,unsigned int secs);
+void taia_uint(tai6464 *t,unsigned int secs);
 
 #endif
diff --git a/taia/taia_addsec.c b/taia/taia_addsec.c
new file mode 100644
index 0000000..03a04b5
--- /dev/null
+++ b/taia/taia_addsec.c
@@ -0,0 +1,10 @@
+#include "taia.h"
+
+/* XXX: breaks tai encapsulation */
+
+void taia_addsec(struct taia *t,const struct taia *u,long secs)
+{
+  t->sec.x = u->sec.x + secs;
+  t->nano = u->nano;
+  t->atto = u->atto;
+}
diff --git a/test/io3.c b/test/io3.c
new file mode 100644
index 0000000..1343b8e
--- /dev/null
+++ b/test/io3.c
@@ -0,0 +1,39 @@
+#include <unistd.h>
+#include "buffer.h"
+#include "io.h"
+
+main() {
+  int64 pfd[2];
+  char buf[20480];
+  int i;
+  if (!io_pipe(pfd)) return 111;
+  io_nonblock(pfd[1]);
+  if (!io_fd(pfd[1])) return 111;
+  switch (fork()) {
+  case -1: return 111;
+  case 0: /* child */
+	   io_close(pfd[1]);
+	   sleep(1);
+	   for (;;) {
+	    switch (io_waitread(pfd[0],buf,sizeof buf)) {
+	    case -1: buffer_putsflush(buffer_2,"io_waitread returned -1!\n"); return 111;
+	    case -3: buffer_puts(buffer_2,"io_waitread: ");
+		      buffer_puterror(buffer_2);
+		      buffer_putnlflush(buffer_2);
+		      return 111;
+	    case 0: io_close(pfd[0]);
+		    return 0;
+	    }
+	   }
+  }
+  io_close(pfd[0]);
+  for (i=0; i<sizeof(buf); ++i) buf[i]="abcdefghihjklmnopqrstuvwxyz"[i%26];
+  for (i=0; i<1000; ++i) {
+    int64 r;
+    if ((r=io_waitwrite(pfd[1],buf,sizeof buf))!=sizeof buf) {
+      buffer_puts(buffer_2,"io_waitwrite returned ");
+      buffer_putlonglong(buffer_2,r);
+      buffer_putnlflush(buffer_2);
+    }
+  }
+}
diff --git a/test/io4.c b/test/io4.c
new file mode 100644
index 0000000..7194356
--- /dev/null
+++ b/test/io4.c
@@ -0,0 +1,26 @@
+#include "io.h"
+#include "buffer.h"
+
+main() {
+  char buf[2048];
+  int64 pfd[2];
+  tai6464 t;
+  int64 r;
+
+  if (!io_pipe(pfd)) {
+    buffer_puts(buffer_2,"io_pipe: ");
+    buffer_puterror(buffer_2);
+    buffer_putnlflush(buffer_2);
+    return 111;
+  }
+  taia_now(&t);
+  taia_addsec(&t,&t,1);
+  if (!io_fd(pfd[0])) return 111;
+  io_timeout(pfd[0],t);
+  if ((r=io_tryreadtimeout(pfd[0],buf,sizeof buf))!=-2) {
+    buffer_puts(buffer_2,"io_tryreadtimeout returned ");
+    buffer_putlonglong(buffer_2,r);
+    buffer_putnlflush(buffer_2);
+    return 111;
+  }
+}