On 2025-01-10 01:35, Jochen Bern wrote:
On 10.01.25 00:33, Corey Hickey wrote:
I took the approach of preserving current behavior by default, but
another approach would be to:
* print "The agent has no identities." to stderr instead of stdout
* exit with a status of 0 instead of 1
Please don't. If you want to ever get people to load their privkeys into
the agent *with a limited lifetime*, having a trivial, *universal* way
to check whether they have expired by now is an asset.
workplace$ egrep ' ssh(|add)=' .bashrc
alias sshadd='( echo -n "`tput dim`" ; ssh-add -c -t 1800 ; echo -n "`tput sgr0`" )'
alias ssh='ssh-add -l >/dev/null || sshadd ; ssh'
With my patch v2, that would need to be:
> alias ssh='ssh-add -l | grep -q . || sshadd ; ssh'
...though the message "The agent has no identities." would be printed to
stderr, for better or for worse. Perhaps that should require a higher
log_level (via -v).
I can definitely see that there can be potential harm in changing
default behavior, if people are relying on the current behavior. That's
why my first patch did not change the default.
That said, I do think the current behavior is not optimal. In a general
sense, when listing something, an empty list is a valid outcome. If the
listing tool returns an error status after _successfully_ determining
that the list is empty, then the caller cannot easily know whether the
tool succeeded or was unable to determine the list.
For some precedence:
$ mkdir x ; ls x ; echo "ls: $?" ; find x -mindepth 1 ; echo "find: $?"
ls: 0
find: 0
$ awk '/foo/' /etc/passwd ; echo "awk: $?"
awk: 0
$ sed -n '/foo/p' /etc/passwd ; echo "sed: $?"
sed: 0
Of course, I can't say that all tools work this way. Here are a couple
that do not:
$ ps -u games ; echo "ps: $?" ; grep foo /etc/passwd ; echo "grep: $?"
PID TTY TIME CMD
ps: 1
grep: 1
...but I do find it easier to work with listing-tools that consider an
empty list to not be an error.
I can adjust and refine whichever approach the maintainers think is best.
Thanks,
Corey
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