+dnl CF_FOPEN_BIN_R version: 1 updated: 2019/03/30 17:52:21
+dnl --------------
+dnl Check if fopen works when the "b" (binary) flag is added to the mode
+dnl parameter. POSIX ignores the "b", which c89 specified. Some very old
+dnl systems do not accept it.
+AC_DEFUN([CF_FOPEN_BIN_R],[
+AC_CACHE_CHECK(if fopen accepts explicit binary mode,cf_cv_fopen_bin_r,[
+ AC_TRY_RUN([
+#include <stdio.h>
+int main(void) {
+ FILE *fp = fopen("conftest.tmp", "wb");
+ int rc = 0;
+ if (fp != 0) {
+ int p, q;
+ for (p = 0; p < 256; ++p) {
+ fputc(p, fp);
+ }
+ fclose(fp);
+ fp = fopen("conftest.tmp", "rb");
+ if (fp != 0) {
+ for (p = 0; p < 256; ++p) {
+ q = fgetc(fp);
+ if (q != p) {
+ rc = 1;
+ break;
+ }
+ }
+ } else {
+ rc = 1;
+ }
+ } else {
+ rc = 1;
+ }
+ ${cf_cv_main_return:-return} (rc);
+}
+],
+ [cf_cv_fopen_bin_r=yes],
+ [cf_cv_fopen_bin_r=no],
+ [cf_cv_fopen_bin_r=unknown])
+])
+test "x$cf_cv_fopen_bin_r" != xno && AC_DEFINE(USE_FOPEN_BIN_R)
+])dnl
+dnl ---------------------------------------------------------------------------