Beginner PHP Tutorial - 82 - File Handling: Listing Files Part 1 Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

hi this is Alex from PHP academy' dog
back with another video for the new
Boston now we've already looked at file
handling and how to you know open a file
have a look at the contents however what
we need to look at is how we can read a
specific directory and list all files so
you've probably already already guessed
there's going to be a loop somewhere in
here to loop through the contents of a
directory and display each file and what
we're going to be doing is we're going
to just be displaying this as a list and
then we're going to create a hyperlink
for each file so we can click on it now
first of all let me explain why this
might be useful let's say you were
creating some kind of file based photo
gallery and you wanted to have several
folders for example let me just take
this just take a look at the directory
structure that I've chosen
I've got file dot PHP which I have
opened in my text editor and I've got
this files directory here now inside
here let's just put a star in there
we've got first file dot txt second file
dot txt and third file dot txt now what
we're going to be doing is we're going
to be looking inside this files
directory and listing all files now what
happens if these were images you may
have you may want to create a PHP script
that searches a particular directory for
a list of images and then displays them
on a page so you can adapt this example
that I'm going to use really really
easily into your website and for your
own purposes so we're going to be using
two different functions we're going to
use in the open directory and the read
directory now you probably guess the
difference between the two the open
directory function will actually open
the directory and load it into a handle
much like we've done previously with
loading a file into a into a handle then
we can do something with it with the
read directory we're going to put this
into the loop and create the read
directory as another variable so the
redirect tree is going to read the
handle which is then going to equate to
another variable good file so you'll
understand probably a bit better when I
go into the example and show you so the
first thing we need to do is set up a
variable called directory and I'm doing
this simply so I can reuse this over and
over again in my program now remember
the directory that we want to open is
file so I'm going to just
pin files there I'm not going to include
any trailing slashes or anything like
that I'm going to let my my program
handle this later on especially when say
you were releasing this too releasing
some kind of script that use this to the
public you might want to create a
variable such as file to read or
something now you don't want your user
to have to think oh do I need to put a
slash there or a forward slash here or
whatever so you just want to have this
as a single single string with no other
symbols in just to make it a lot easier
for you and anyone that might be looking
at your code so now what we want to do
is we want to create a handle for we're
using the open dir and open dir function
so we say handle equals open dir and
obviously we're going to be opening the
directory that we've just specified but
then what we're going to be doing is
appending on a forward slash so in
actual fact when you read it in here the
directory is going to look like that but
we're just leaving this up to this line
of code now we need to ensure that this
returns a true value so we need to
ensure that this actually does open
before we continue with the rest of our
code otherwise the rest of our code is
going to be invalid so what we need to
do is put this in an if statement much
like we've put in a few other things
like connecting to a database for
example or or just anything really we
want to return true so we can do this we
can set a variable at the same time as
calling a function so if this is true
then we need to go ahead and continue
the next step now just for just for
purposes of you know aesthetics making
it look nice so I'm going to echo out
looking inside and then I'm going to put
the directory name just here so I'm
going to say directory like that so
it'll read looking inside files this is
another reason I didn't do slashes
because it we're just going to specify
the directory as plain string you know
how we how we want it to look and what
we're looking inside and I'm just going
to append a break on there I'm also
going to enclose this directory text in
inside single quotation marks let's have
a look at it at the moment okay so this
is looking inside file so I want just
single quotation marks on the outside of
this to ensure that we enclose it so I'm
going to put a single quotation mark
there and escape that character so it
doesn't interfere with the start or end
of our string and I'm going to do the
same just after that break and then put
a escape string there a state character
there I'm sorry
so now let's refresh and we can see that
that's just been enclosed in single
quotation marks we can even then just
add a colon just to make it look a bit
nicer okay so we've established our
little welcome or a little message
telling everyone what we're doing now
what we need to do is we need to
actually read the directory so this is
slightly different we're going to be
using a while loop so let's come down a
bit and we'll set up the skeleton for
our while loop now inside here what we
need to do is we first need to assign
the variable file to reading the
directory because what's going to happen
is file is then going to exist forever
every loop it's going to exist for each
element or if each file in our directory