openssh at tr.id.au
2025-Oct-14 00:28 UTC
On the impossibility to use escape sequences when the networks hangs
> > In short: how does one control an interactive connection that > > currently is incapable to send/receive data? ssh just hangs. > > > What happens if you try : > > $ ssh -e\^ -l someusername remotehost > > I use that sort of thing all the time. The manpage says : > > -e escape_char > Set the escape character for sessions with a pty (default: '~'). > The escape character is only recognized at the beginning of a > line. ... <snip>I believe it's easy to overlook/forget the requirement: "The escape character is only recognized at the beginning of a line." I suppose using this sequence would solve the OP's issue: <Enter>~. (aka <Enter><Shift-Backtick><Period>) Indeed, this should be processed client-side. I've never had a problem killing a hung connection once I remembered to always prefix the escape with a newline. ~ Tim
Dennis Clarke
2025-Oct-14 00:38 UTC
On the impossibility to use escape sequences when the networks hangs
On 10/13/25 20:28, Tim Rice via openssh-unix-dev wrote:>>> In short: how does one control an interactive connection that >>> currently is incapable to send/receive data? ssh just hangs. >> >> >> What happens if you try : >> >> $ ssh -e\^ -l someusername remotehost >> >> I use that sort of thing all the time. The manpage says : >> >> -e escape_char >> Set the escape character for sessions with a pty (default: '~'). >> The escape character is only recognized at the beginning of a >> line. ... <snip> > > I believe it's easy to overlook/forget the requirement: ...Yes ... I had forgotten that. n# n# ^? Supported escape sequences: ^. - terminate connection (and any multiplexed sessions) ^B - send a BREAK to the remote system ^R - request rekey ^V/v - decrease/increase verbosity (LogLevel) ^^Z - suspend ssh ^# - list forwarded connections ^& - background ssh (when waiting for connections to terminate) ^? - this message ^^ - send the escape character by typing it twice (Note that escapes are only recognized immediately after newline.) n# Seems to work fine at the beginning of a line. :/ -- -- Dennis Clarke RISC-V/SPARC/PPC/ARM/CISC UNIX and Linux spoken