[zzo38computer]

Here is another implementation using Node.js (although it does not explicitly check for EOF):

  require("fs").createReadStream(process.argv[2]).pipe(process.stdout)

Here is a implementation in PostScript (it does explicitly check for EOF, and specifically deals with one byte at a time):

  /o (%stdout) (w) file def
  ARGUMENTS 0 get (r) file
  {
    dup read {
      o exch write
    } {
      quit
    } ifelse
  } bind loop

(I have no GitHub account. But if the owner of that repository want to add, they can add what I have; I post this message (and all of my other messages on Hacker News) to public domain.)

[rspivak]

Thank you for the implementations! Do you have any suggestions how to test the postscript code on mac/linux? I tried on macos using ghostscript, but I get the following error:

$ gs cat.ps helloworld.txt

Error: /undefined in ARGUMENTS ...

Thanks!

[zzo38computer]

To give command-line arguments to a PostScript program in Ghostscript, you must prefix the name of the PostScript file with two minus signs, such as:

  gs -dNODISPLAY -q -- cat.ps helloworld.txt

(The -dNODISPLAY and -q are not needed to get this PostScript program to work, but -dNODISPLAY disables graphical output, and -q avoids Ghostscript's messages getting mixed in with the PostScript program's output. You might also need -dNOSAFER; if you get a invalidaccess error, try that. As far as I know, ARGUMENTS and -- are a feature specific to Ghostscript.)