+AC_CHECK_FUNCS(usleep ftello sigblock sigsetjmp symlink)
+
+dnl We expect to have these functions on Unix-like systems configure
+dnl runs on. The defines are provided to get them in config.h.in so
+dnl Wget can still be ported to non-Unix systems (such as Windows)
+dnl that lack some of these functions.
+AC_DEFINE([HAVE_STRCASECMP], 1, [Define to 1 if you have the `strcasecmp' function.])
+AC_DEFINE([HAVE_STRNCASECMP], 1, [Define to 1 if you have the `strncasecmp' function.])
+AC_DEFINE([HAVE_STRDUP], 1, [Define to 1 if you have the `strdup' function.])
+AC_DEFINE([HAVE_ISATTY], 1, [Define to 1 if you have the `isatty' function.])
+AC_DEFINE([HAVE_SYMLINK], 1, [Define to 1 if you have the `symlink' function.])