| # Check for support for nanosleep.  It's defined in <time.h>, but on | 
 | # some systems, such as solaris, you need to link in a library to use it. | 
 | # We set acx_nanosleep_ok if nanosleep is supported; in that case, | 
 | # NANOSLEEP_LIBS is set to whatever libraries are needed to support | 
 | # nanosleep. | 
 |  | 
 | AC_DEFUN([ACX_NANOSLEEP], | 
 | [AC_MSG_CHECKING(if nanosleep requires any libraries) | 
 |  AC_LANG_SAVE | 
 |  AC_LANG_C | 
 |  acx_nanosleep_ok="no" | 
 |  NANOSLEEP_LIBS= | 
 |  # For most folks, this should just work | 
 |  AC_TRY_LINK([#include <time.h>], | 
 |              [static struct timespec ts; nanosleep(&ts, NULL);], | 
 |              [acx_nanosleep_ok=yes]) | 
 |  # For solaris, we may  need -lrt | 
 |  if test "x$acx_nanosleep_ok" != "xyes"; then | 
 |    OLD_LIBS="$LIBS" | 
 |    LIBS="-lrt $LIBS" | 
 |    AC_TRY_LINK([#include <time.h>], | 
 |                [static struct timespec ts; nanosleep(&ts, NULL);], | 
 |                [acx_nanosleep_ok=yes]) | 
 |    if test "x$acx_nanosleep_ok" = "xyes"; then | 
 |      NANOSLEEP_LIBS="-lrt" | 
 |    fi | 
 |    LIBS="$OLD_LIBS" | 
 |  fi | 
 |  if test "x$acx_nanosleep_ok" != "xyes"; then | 
 |    AC_MSG_ERROR([cannot find the nanosleep function]) | 
 |  else | 
 |    AC_MSG_RESULT(${NANOSLEEP_LIBS:-no}) | 
 |  fi | 
 |  AC_LANG_RESTORE | 
 | ]) |