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Table of Contents

Filter Files

Filter configuration (ctrl/*.cfg) and trash can (text/*.can) files allow the sysop to specify words (or any sequence of characters) that will be used to disallow clients, users, or their content.

Each line in a filter file may contain a comparison sequence. Blank lines and lines beginning with a semicolon are ignored

Comparison Sequences

  • Sequences of alphabetic letters are treated case-insensitively
  • Sequences beginning with an exclamation mark (!) negate the match logic for that sequence
  • Sequences beginning with an asterisk (*) match only if the characters following the * are found at the end of the comparison string
  • Sequences ending with an asterisk (*) or caret (^) match only if the characters preceding are found at the beginning of the comparison string
  • Sequences ending with a tilde (~) match only if the preceding characters are found anywhere within comparison string
  • All other sequences are “exact match” string comparisons

Examples:

  • sysop in the name.can file would mean users could not use the name “sysop”.
  • sysop* would mean users could not use names beginning with the word “sysop”, like “sysopa” or “sysops” etc.
  • sysop~ would mean users could not use names that have the word “sysop” anywhere in them, like “imthesysop” or “mesysophere”.

Trash Can Files

The following table lists the supported trash can files, a description of their use, and optional response message (.msg) files that may be displayed to users that are filtered. Trash can files and their respective optional response files are located in the text directory:

Filename / Page Default ContentsDescription
email.can email.canDisallowed (source or destination) e-mail addresses (see also twitlist.cfg)
bademail.msgOptional message to display to users attempting to use a disallowed email address
file.can file.canDisallowed filenames for upload
badfile.msgOptional message to display to users who attempt to upload a disallowed filename
host.can host.canDisallowed hostnames for connections
badhost.msgOptional message to display to users who attempt to connect from a disallowed host
ip.can ip.canDisallowed IP addresses for connections
badip.msgOptional message to display to users who attempt to connect from a disallowed IP address
ip-silent.can ip-silent.canSilently-ignored IP addresses for connections
name.can name.canDisallowed user login name/alias (see also block-hackers)
badname.msgOptional message to display to users who attempt to use a disallowed login name
phone.can phone.canDisallowed phone numbers for new users
badphone.msgOptional message to display to users who attempt to use a disallowed phone number
subject.can subject.canDisallowed message subjects
badsubject.msgOptional message to display to users who attempt to use a disallowed subject in a posted message

Other Filter Files

The following table lists other supported filter files and a description of their use. These filter files are located in the ctrl directory and do not have a respective response message file:

Filename / Page Default ContentsDescription
spamblock.cfg spamblock.cfgHostnames and IP addresses blocked from sending e-mail to the Mail Server (see also spamblock_exempt.cfg)
twitlist.cfg twitlist.cfgDisallowed (source or destination) e-mail addresses (enclosed in <angle brackets>) or names (see also email.can)

Filter Exemption Files

The following table lists supported filter exemption files and a description of their use. These filter exemption files are located in the ctrl directory:

Filename / Page Default ContentsDescription
dnsbl_exempt.cfg dnsbl_exempt.cfgHostnames and IP addresses and e-mail address (enclosed in <angle brackets>) which are to be exempt from positive DNS-based Blacklist results in the Mail Server (see also dns_blacklist.cfg)
spamblock_exempt.cfg spamblock_exempt.cfgHostnames and IP addresses which are not to be blocked from sending e-mail to the Mail Server (see also spamblock.cfg)

See Also

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Trace: • Filter Files