proj
only takes input files as its arguments. You need to redirect the standard output to your file:
$ proj -m 57.295779506 +proj=ob_tran +o_proj=latlon +o_lon_p=83 +o_lat_p=42.5 +lon_0=180 ifile.txt > ofile.txt
If you want to print to standard output AND the file, you can do
$ proj ... | tee ofile.txt