Writing Files Line by Line

Reading files will allow you to retrieve data from manipulation. 0:00 But what if you want to share this information with others? 0:03 Writing files will allow us to save any changes we make and 0:07 also allow us to change settings and update application details. 0:11 Building upon the same methods we use for 0:15 reading files, lets take a look at a couple different ways to write files. 0:17 We're going to combine our states into a single file. 0:23 Let's start with the new file named combine.php. 0:26 We'll start by opening a new file for writing line by line. 0:39 Once again, we use fopen. 0:44 We'll call this data/html/combined.html. 0:49 This time for the mode, we use w for write. 0:57 This tells a function to open the file for writing only. 1:02 It places the file pointer at the beginning of the file and 1:05 truncates the file to zero length. 1:08 This has the effect of erasing the file, so be careful when you use it. 1:11 If the file does not exist, it will attempt to create it. 1:16 Again, I'll surround the statement with the conditional, so 1:20 we don't try to write to a file we can't access. 1:23 Then within the conditional, I'll close the file. 1:33 We then start writing to the file using the fwrite function. 1:43 Like with fgets we pass the handler that we used in the fopen statement. 1:48 This time, we also passed the string we want to write. 1:55 I want to start with the original states file. 1:59 So I can use file_ get_ contents, 2:02 data/html/states.html. 2:08 Next, I want to write the territories within an opt group. 2:14 Again, I can use the file_get_contents, and 2:54 this time I'll use data/html/territories.html. 3:00 Now, do the same thing for the Armed Forces. 3:07 We already finished with fclose. 3:30 So, let's add a select and include the file we just wrote so 3:33 that we can check this out in the browser. 3:36 Great, now we have a single file to use first state dropdown. 4:10 If you view the source, you can see that it's a little hard to read 4:18 because we don't have proper line breaks. 4:23 Let's go back and add those. 4:27 A good way to add line breaks to a file is with the predefined constant PHP_EOL. 4:29 This will add the correct end of line symbol for 4:35 the platform where the script is running. 4:38 We'll add this before all but the first write. 4:45 Now, we may refresh the source. 5:15 Our line breaks show up nicely making the file easier to read. 5:16 Let's go back to work spaces and look at writing the entire file at once. 5:21