RLOGIN(1)

💻 RLOGIN(1) — remote login, but make it a whole vibe

okay bestie, so this is rlogin from the General Commands Manual — like, the actual legit one, not a knockoff. it's the remote login girlie and she has lore. let's get into it 🎀

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✨ NAME ✨

rlogin — remote login (yes that's literally the whole name, she's an icon, she doesn't need more) 💅

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🦋 SYNOPSIS 🦋

rlogin rhost [-ec] [-8] [-c] [ -a] [-f] [-F] [-t termtype] [-n] [-7]
[-PN | -PO] [-d] [-k realm] [-x] [-L] [-l username]

not me giving you the whole flag buffet up front — no cap, we're gonna go through every single one 🫶

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🌸 DESCRIPTION 🌸

so rlogin connects your terminal on the current local host system, lhost, to the remote host system, rhost. that's the whole thing. main character behavior honestly 🔥

the version that's built to use Kerberos authentication is very similar to the standard Berkeley rlogin(1), except — and this is the glow-up — instead of using the rhosts mechanism, it uses Kerberos authentication to decide whether you're authorized to use a remote account. periodt 💜

each user may have a private authorization list in a file .k5login in their login directory. every line in this file should contain a Kerberos principal name of the form principal/instance@realm. if the originating user is authenticated to one of the principals named in .k5login, access is granted to the account. if there is no /.k5login file, the principal will be granted access to the account according to the aname->lname mapping rules. (see krb5_anadd(8) for more details, iykyk.) otherwise a login and password will be prompted for on the remote machine, just like in login(1). and bestie, listen — to avoid some security problems, the .k5login file must be owned by the remote user. no exceptions, that's the rule 💀

if there's some problem in marshaling the Kerberos authentication information, an error message is printed and the standard UCB rlogin is executed in place of the Kerberos rlogin. like, it just swaps itself out mid-situation. resilient queen 🙈

a line of the form ~. disconnects from the remote host, where ~ is the escape character. similarly, the line ~^Z (where ^Z, control-Z, is the suspend character) will suspend the rlogin session. substituting the delayed-suspend character (normally ^Y) for the suspend character suspends the send portion of the rlogin, but lets output from the remote system keep flowing. it's giving "half asleep but still streaming" 😭

the remote terminal type is the same as your local terminal type (as given in your environment TERM variable), unless the -t option is specified (see below, boo). the terminal or window size is also copied to the remote system if the server supports the option, and changes in size are reflected as well. she's adaptable 🧚

all echoing takes place at the remote site, so that (except for delays) the rlogin is transparent. flow control via ^S and ^Q and flushing of input and output on interrupts are handled properly. she handles all of it. flawless. no notes ⭐

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👑 OPTIONS 👑

• -8 — allows an eight-bit input data path at all times; otherwise parity bits are stripped except when the remote side's stop and start characters are other than ^S/^Q. eight-bit mode is the default, so she already ate 💅
• -L — allows the rlogin session to be run in litout mode. lowkey mysterious but okay 🦋
• -ec — sets the escape character to c. and no, there is no space separating this option flag and the new escape character. it's glued together, that's the bit, don't fight it 🎀
• -c — require confirmation before disconnecting via ~.. she asks "are you sure bestie" first, which is honestly so valid 🫶
• -a — force the remote machine to ask for a password by sending a null local username. heads up: this option has no effect unless the standard UCB rlogin is executed in place of the Kerberos rlogin (see above, scroll up boo) 🙈
• -f — forward a copy of the local credentials to the remote system.
• -F — forward a forwardable copy of the local credentials to the remote system. yes there's a difference, she's fancy ✨
• -t termtype — replace the terminal type passed to the remote host with termtype.
• -n — prevent suspension of rlogin via ~^Z or ~^Y. no napping allowed 😭
• -7 — force seven-bit transmissions. retro vibes.
• -d — turn on socket debugging (via setsockopt(2)) on the TCP sockets used for communication with the remote host. nerdy and we love that for her 🔥
• -k realm — request rlogin to obtain tickets for the remote host in realm realm instead of the remote host's realm as determined by krb_realmofhost(3).
• -x — turn on DES encryption for data passed via the rlogin session. important caveat bestie: this applies only to input and output streams, so the username is sent unencrypted. also it significantly reduces response time and significantly increases CPU utilization. so like, secure-ish but she is working for it 💀
• -PN
• -PO — explicitly request new or old version of the Kerberos rcmd protocol. the new protocol avoids many security problems found in the old one, but is not interoperable with older servers. (an "input/output error" and a closed connection is the most likely result of attempting this combination — yeah, that's the sound of it not working 😭) if neither option is specified, some simple heuristics are used to guess which to try. she guesses. confidently. 🌈

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🌟 SEE ALSO 🌟

rsh(1), kerberos(1), krb_sendauth(3), krb_realmofhost(3), rlogin(1) [UCB version], klogind(8)

the whole friend group, go say hi 🫶

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🍓 FILES 🍓

• ~/.k5login (on remote host) — file containing Kerberos principals that are allowed access. this is the VIP list, and you are not on it unless you're on it 💅

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💀 BUGS 💀

more of the environment should be propagated. that's it. that's the bug. she said "I could be doing more and I'm not" and honestly? relatable 😭

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and that's the page, bestie!! this was RLOGIN(1) from the General Commands Manual — same source, same version tag, same date as always, no cap. go remote login responsibly, and remember: the escape character is ~ and the .k5login must be owned by the remote user. love u, bye 💖✨🎀🦋