+#include <stdio.h>
+#include <limits.h>
+#include <stdint.h>
+
+uint16_t read_uint16_bigendian(FILE * file) {
+// Read uint16 from file in big-endian order.
+ const uint16_t nchar = UCHAR_MAX + 1;
+ unsigned char a = fgetc(file);
+ unsigned char b = fgetc(file);
+ return (a * nchar) + b; }
+
+void write_uint16_bigendian(uint16_t x, FILE * file) {
+// Write uint16 to file in beg-endian order.
+ const uint16_t nchar = UCHAR_MAX + 1;
+ unsigned char a = x / nchar;
+ unsigned char b = x % nchar;
+ fputc(a, file);
+ fputc(b, file); }
+
+uint32_t read_uint32_bigendian(FILE * file) {
+// Read uint32 from file in big-endian order.
+ const uint16_t nchar = UCHAR_MAX + 1;
+ unsigned char a = fgetc(file);
+ unsigned char b = fgetc(file);
+ unsigned char c = fgetc(file);
+ unsigned char d = fgetc(file);
+ return (a * nchar * nchar * nchar) + (b * nchar * nchar) + (c * nchar) + d; }
+
+void write_uint32_bigendian(uint32_t x, FILE * file) {
+// Write uint32 to file in beg-endian order.
+ const uint16_t nchar = UCHAR_MAX + 1;
+ unsigned char a = x / (nchar * nchar * nchar);
+ unsigned char b = (x - (a * nchar * nchar * nchar)) / (nchar * nchar);
+ unsigned char c = (x - ((a * nchar * nchar * nchar) + (b * nchar * nchar))) / nchar;
+ unsigned char d = x % nchar;
+ fputc(a, file);
+ fputc(b, file);
+ fputc(c, file);
+ fputc(d, file); }
+