Modify the program in Listing 64-3 (script.c) to add a time-stamped recording feature. Each time the program writes a string to the typescript file, it should also write a time-stamped string to a second file (say, typescript.timed). Records written to this second file might have the following general form:
The timestamp should be recorded in text form as the number of milliseconds since the start of the script session. Recording the timestamp in text form has the advantage that the resulting file is human-readable. Within string, real newline characters will need to be escaped. One possibility is to record a newline as the 2-character sequence \n and a backslash as \\.
Write a second program, script_replay.c, that reads the time-stamped script file and displays its contents on standard output at the same rate at which they were originally written. Together, these two programs provide a simple recording and playback feature for shell session logs.