Comment by frou_dh

It bugged me that Sublime Text used to do these so-called atomic saves by default since it screwed with basic unix expectations like fstat and fseek meaningfully working (like a tail -f implementation could boil down to[0]). A concurrently running process using those calls would be off in lala-land as soon as the text file was modified and saved: it would never pick up any modifications, because it and the editor weren't even dealing with the same file any more.

[0] Here's follow(1) in my homemade PL:

    #!/usr/bin/env imp
    
    (when (not-eq? (length script-args) 1)
          (write (sprintln "usage: " script-name " <path>") stderr)
          (exit 1))

    (let path (car script-args)
         f (open path)
         ((proc (stat-then)
                (let stat-now (stat f)
                     (seq (when (and? stat-then
                                      (lt? (find 'size stat-now)
                                           (find 'size stat-then)))
                                # The file was truncated. Read from the start.
                                (seek s-set 0 f))
                           (let bytes (read default-chunk f)
                                (seq (when bytes (print bytes))
                                     (sleep 1000)
                                     (recur stat-now))))))
          FALSE))