I. DESCRIPTION

This is a backup program. The name hbackup has been chosen because of the way
data is stored: based on the file hash (a la git).

Why yet another backup program? Because I wanted something geared towards what
I do: software development. This system can easily be made to recognise
version-controlled directories to optimise backup choices: why re-backup files
that are on a server somewhere, itself with its own backup system?

II. SERVER CONFIGURATION

The default configuration file is /etc/hbackup/hbackup.conf, and can be
overriden using the -c option. The following keywords are acceptable there:
* db gives the backup database path. The default is '/hbackup'.
  Syntax:  db "<path to backup database>"
  Example: db "/backup"
* client gives the client name.
  Syntax:  client "protocol" "<client desired name>"
  Example: client file "montblanc"

The client keyword can be followed by the following keywords:
* listfile is mandatory as it gives the path to the backup list file.
  Syntax:             listfile "<path to file>"
  Example (smb):      listfile "C:/Backup/hbackup.list"
  Example (file/nfs): listfile "/etc/hbackup.list"
* hostname is used by network (smb and nfs) protocols to specify a network host
  name (if different from the client name) or IP address.
  Syntax:               hostname "<host name or IP address>"
  Example (name):       hostname "everest"
  Example (IP address): hostname "192.168.0.2"
* option can be used to specify any file system option.
  Syntax:  option <option name>
  Syntax:  option <option name> "<option value>"
  Example: option nocase
  Example: option nolock
  Example: option username "herve"
  Example: option iocharset "utf8"

Note for the SMB protocol users: hbackup uses CIFS, and as such will NOT use
the SMB protocol to resolve client names.

III. CLIENT CONFIGURATION

A. Client setup

1. Network File System (NFS)

It is warmly recommended for the client to export to the backup server only,
with the following options: read-only, no squash.

Example of /etc/exports entry, where fujiyama is the name of the backup server:
/home fujiyama(no_root_squash,no_all_squash,ro)

2. Server Message Block (SMB)

By default, Windows XP and Windows Vista will authenticate all users as guests
when accessed remotely. For hbackup to work properly, such computers need to be
told to use the classic authentication which authenticates users as themselves,
so the administrative shares can be mounted as Administrator.

Instructions:
  Start -> Control Panel -> Administrative Tools -> Local Security Policy
  On the left hand side, expand Local Policies (click the + sign)
  Click Security Options
  On the right hand side, find Network access: Sharing and security model...
  Double click it, change to Classic - local users authenticate as themselves
  Click OK, quit Local Security Policy then quit Administrative Tools

B. Configuration file

Each client must provide its own configuration file. Keywords that may be used:
* path:   start of a new backup list, gives the path information.
  Syntax: path "<path to backup>"
* ignore: add files filter to skip (see FILTERS below).
* ignand: add AND condition to last files filter (see FILTERS below).
* parser: files under version control (see PARSERS below).
* expire: delay in days after which removed files can be erased from database

1. COMPRESSION

No compression is enabled for now.

2. FILTERS

Syntax: [ignore|ignand] <filter type> "<string>"

There are six filter types:
* type:         match file type
* name:         match file name
* name_start:   match start of file name
* name_end:     match end of file name
* name_regex:   match regular expression on file name
* path:         match path
* path_start:   match start of path
* path_end:     match end of path
* path_regex:   match regular expression on path
* size_above:   match files which size is above or equals given value
* size_below:   match files which size is below or equals given value

There are seven file types:
* f or file:    regular file
* d or dir:     directory
* c or char:    character device
* b or block:   block device
* p or pipe:    named pipe or FIFO
* l or link:    symbolic link
* s or socket:  socket

Example:
ignore path_start abr
ignand type file
ignand size_above 5000

This will ignore all regular files which name starts in abr (abr*) and size is
greater than or equal to 5000.

3. PARSERS

Syntax: parser "<parser name>" <mode>

Only one parser is implemented at the moment:
* cvs: this parser does not check for file modification

There are four modes (only the first letter matters):
* m: backup files under control, that were modified locally (m for modified)
* o: backup files not under control (o for others)
* l: backup files in the two cases above (l for local)
* c: backup all files under control (c for controlled)

Note: parsers that do not check for file modification shall backup all
controlled files if 'modified' was chosen, or all files if 'local' was chosen.