The best replacement for fopen is open.

The best alternatives to fopen are rated as following:
★★★★★  open
★★★★  curl
★★★★  file_get_contents
★★★  fstream
★★★  fopen_s
★★  createfile
★★  fsockopen
★★  fdopen
★★  freopen
★  file php
★  ifstream
★  mmap
★  fopen s
★  open c programming
  open c
  iostream
  readfile
  fstream c++
  _wfopen

Your alternative for fopen is not listed? Suggest!
Speaking about fopen, one probably shouldn't forget about rb.

Other search terms related to fopen and their ratings are:
★★★★★ rb
★ fclose
You have in mind a companion for fopen and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of fopen in all years. Click on graph for more.
fopen
open
curl