rblckeck(1)

✨ NAME ✨

rblckeck — a DNSBL lookup utility 💅 (yes bestie, the manual page is literally titled rblckeck, that's the page name we're working with, and the command inside it is rblcheck, we're keeping both exactly as they are, no cap)

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🎀 SYNOPSYS 🎀

rblcheck [-s zone] [-S zone-file] [-c] [-tmvq] [-n nsaddr] address...

Not me noticing the original spells the section "SYNOPSYS" — keeping it, that's canon now, it's part of the lore 🫶

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🦋 DESCRIPTION 🦋

So rblcheck is a simple command-line tool that does DNSBL lookups — DNSBL meaning DNS-based blocklists, iykyk. It's giving "is this IP on the naughty list" but make it a whole utility. 👑

Here's the vibe: for every IP address you hand it — or a name, and if it's a name it'll get resolved to an address first, no worries — the utility verifies whenever it is listed in a (list of) DNS blocklists that you specified with the -s or -S options. Optionally it also snags the text associated with the listing (usually that's either some description about the reason of the listing, or an URL referring to such a description, so like a little receipt for why you got listed 📝), and then it displays results on standard output.

The program is implemented on top of udns(3) library. That's the whole architecture, that's the flex. ✨

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💖 OPTIONS 💖

The following options are recognized by rblcheck:

• -s zone — add the given zone DNSBL name to the list of active zones. Like, this one goes on the list. ✅
• -S zone-file — add list of zones from the named zone-file to the list of active zones. Heads up on the file format bestie: the file specifies one zone as the first word on a line, and empty lines and lines starting with a `#` character are ignored. 📄
• -c — reset active zone list. Fresh start, we love a clean slate. 🧼
• -v — be more verbose, produce more detailed output. She's talking more now. 🗣️
• -q — the opposite for -v — produce less detailed output. She's being mysterious. 🤫
• -t — obtain text for listed addresses. Get the receipts, get the tea. ☕
• -n nsaddr — Use the given nameserver (given as IPv4 or IPv6 address) instead of the default. The same effect may be achieved by setting $NSCACHEIP environment variable. 🌐
• -m — stop after first hit, ie after the first address which is found to be listed. First one's enough, we're out. 🏃♀️
• -h — print short help and exit. Little emergency exit for when you're lost. 🆘

If no -s, -S and -c options are given, rblcheck will try to obtain list of zones using $RBLCHECK_ZONES environment variable, or ~/.rblcheckrc, or /etc/rblckechrc files, in that order. If no zones are found, it will exit unsuccessfuly. 💀

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🌈 RETURN VALUE 🌈

• When no addresses given are listed and no errors occurred, rblcheck exits with code 0. Clean, unproblematic, main character energy. ✨
• If at least one address is listed, rblcheck returns 100. Caught in 4K. 📸
• In case of DNS errors, rblcheck returns 2. Something went sideways. 😭

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🌸 ENVIRONMENT 🌸

• $RBLCHECK_ZONES — if no -s, -S or -c option is given, rblcheck tries this variable to obtain list of DNSBL zones to check against. The environment variable is the first stop on the zone-acquisition tour. 🎟️

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🍓 FILES 🍓

• $HOME/.rblcheckrc and /etc/rblcheckrc — if no -s, -S or -c option is given, and no $RBLCHECK_ZONES environment variable is set, rblcheck will try the two files (the first one that exists) to obtain list of DNSBL zones to check against. Each line specifies one zone (only first word in each line is used). Empty lines and lines starting with a `#` character are ignored. 📂

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🧚 SEE ALSO 🧚

dnsget(1) resolv.conf(5) udns(3).

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👑 AUTHOR 👑

This program and manual pages are written by Michael Tokarev. Respect the author, they ate. 🫶

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okay and that's the whole page bestie, go forth and check those blocklists 💅

User Utilities · Apr 2005 · rblckeck(1) — that's the source, the version vibe and the date, all wrapped up in a little bow, mwah 🎀