LD_PRELOAD hook to intercept read calls to glibc, written in Rust with the assistance of https://github.com/geofft/redhook.

Edit string constants REDIRECT_ORIG_PATH and REDIRECT_TARGET_PATH in src/lib.rs, then recompile with cargo build. When exeuting a program with LD_PRELOAD set to the output library, all reads to REDIRECT_ORIG_PATH will instead go to REDIRECT_TARGET_PATH.

Supposing that this library was compiled using REDIRECT_ORIG_PATH="file1.txt" and REDIRECT_TARGET_PATH="file2.txt":

$ echo "File 1" > file1.txt
$ echo "File 2" > file2.txt
$ LD_PRELOAD=./libredirect_read.so cat file1.txt 
Redirected open("file1.txt") to open("file2.txt")
File 2