Check if FTP entry is file or folder with PHP

问题:

I am working on a script for connecting to an FTP and then download the content.

Now my problem is to detect whether a each item is a folder or a file. My first idea was to try and use ftp_chdir, but this would require me to suppress the error using @, and I don't wish to do this (I don't wish to suppress errors, but instead prefer to handle them correctly).

Is there another way to check if a my items are files or folders?

回答1:

The bad thing about trying the ftp_chdir is not the need to suppress the errors. That's ok, as long as you have a legitimate reason to expect an error. It's rather the side affect of changing the directory.

If I take that direction, I'd try the ftp_size instead, as it does not have any side effects. It should fail for directories and succeed for files.

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If you are connecting to one specific server, so you know its format of directory listing, use the ftp_rawlist, and parse its output to determine, if the entry is file or folder.

Typical listing on a *nix server is like:

drwxr-x---   3 vincent  vincent      4096 Jul 12 12:16 public_ftp
drwxr-x---  15 vincent  vincent      4096 Nov  3 21:31 public_html
-rwxrwxrwx   1 vincent  vincent        11 Jul 12 12:16 file.txt

It's the leading d that tells you, if the entry is a directory or not.

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You may be lucky and in your specific case, you can tell a file from a directory by a file name (i.e. all your files have an extension, while subdirectories do not).

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The ideal solution is to use the MLSD FTP command that returns a reliable machine-readable directory listing. But PHP does not support that.

There's an implementation of the MLSD in user comments of the ftp_rawlist command:
https://secure.php.net/manual/en/function.ftp-rawlist.php#101071

回答2:

In case someone need this in 2018+

You can use ftp_nlist. For files you'll retrieve array with only one element (the file path itself), for directories you'll have at least two items in array . and .., and if no file or directory exists there will be an empty array returned.