# Miscellaneous Topics

## Chapter 4. Miscellaneous Topics

## Networktransparency via KIO

### KIO-Slaves

KDE supports networktransparency via KIO-slaves. KDiff3 uses this for reading input files and for scanning directories. This means that you can specify files and directories on local and remote ressources via URLs.

Example:

       kdiff3 test.cpp  ftp://ftp.faraway.org/test.cpp
       kdiff3 tar:/home/hacker/archive.tar.gz/dir ./dir

The first line compares a local file with a file on an FTP-server. The second line compares a directory within an compressed archive with a local directory.

Other KIO-slaves that are interesting are:

- Files from the WWW (http:),

- Files from the FTP (ftp:),

- Encrypted file transfer (fish:, sftp:),

- Windows-ressources (smb:),

- Local files (file:),

Other things that are possible, but probably less useful are:

- Man-pages (man:),

- Info-pages (info:),

### How To Write URLs

An URL has a different syntax compared with paths for local files and directories. Some things should be considered:

- A path can be relative and can contain "." or "..". This is not possible for URLs which are always absolute.

- Special characters must be written with "escaping". ("#"->"%23", space->"%20", etc.) E.g. A file with the name "/#foo#" would have the URL "file:/%23foo%23".

- When URLs don't work as expected, try to open them in Konqueror first.

### Capabilities of KIO-Slaves

Networktransparency has one drawback: Not all ressources have the same cababilities.

Sometimes this is due to the filesystem of the server, sometimes due to the protocol. Here is a short list of restrictions:

- Sometimes there is no support for links.

- Or there is no way to distinguish if a link points to a file or a directory; always assuming a file. (ftp:, sftp:).

- Can't always determine the filesize.

- Limited support for permissions.

- No possibility to modify permissions or modification time, so permissions or time of a copy will differ from the original. (See the option "Trust the size".) (Modify permissions or modification time is only possible for local files.)