Re: where are the crontab files in Trixie?
On 29/02/2024 11:32, David Wright wrote: On Wed 28 Feb 2024 at 22:32:57 (+0700), Max Nikulin wrote: On 28/02/2024 10:35, David Wright wrote: In which case, I'd write the remaining cron line as: @reboot sleep 99 && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id I am in doubts if it is a task for cron. Wouldn't udev rules be better? Those are fair questions. If the appearance of the brcmfmac/ directory is the sole precondition, then I would probably try udev. But I claim no knowledge about the module or any device connected with it. The /sys/bus/usb/drivers/brcmfmac directory should appear when the module is loaded. Likely there is no point to load the module if the device is not plugged, thus udev should be better than /etc/modprobe.d. Where cron/sleep is useful is where some device has to settle, or wait in some way, before the string is sent. One example I use is: @reboot sleep 15 && printf '\n' > /dev/tty1 && /usr/sbin/rfkill > /dev/tty1 && /usr/bin/ip a > /dev/tty1 I would consider a systemd single-shot service that runs after network.target. Instead of "sleep" I would try either nm-online or systemd-networkd-wait-online with timeout. I admit, in some cases they have no advantages over sleep.
Re: where are the crontab files in Trixie?
On Wed 28 Feb 2024 at 22:32:57 (+0700), Max Nikulin wrote: > On 28/02/2024 10:35, David Wright wrote: > > In which case, I'd write the remaining cron line as: > > > >@reboot sleep 99 && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > I am in doubts if it is a task for cron. Wouldn't udev rules be better? > > https://stackoverflow.com/questions/442833/how-to-force-driver-to-device-match-in-linux/52943745#52943745 > https://unix.stackexchange.com/questions/67936/attaching-usb-serial-device-with-custom-pid-to-ttyusb0-on-embedded/165845#165845 > > Moreover, to load and configure modules there are /etc/modprobe.d/ and > /etc/modules. > > If it is a weird device that may appear either as 13b1:0039 (supported > by brcmfmac accordingly to modinfo) and 13b1:0bdc, may it happen that > it is possible to use e.g. usb-modeswitch to adjust which way the > device tries to present itself? Those are fair questions. If the appearance of the brcmfmac/ directory is the sole precondition, then I would probably try udev. But I claim no knowledge about the module or any device connected with it. Where cron/sleep is useful is where some device has to settle, or wait in some way, before the string is sent. One example I use is: @reboot sleep 15 && printf '\n' > /dev/tty1 && /usr/sbin/rfkill > /dev/tty1 && /usr/bin/ip a > /dev/tty1 which tells me whether the hardware toggle switch on my ancient laptop is actually unblocked (the switch's indicator lamp is unreliable) and whether it's connected to the router, and how. Cheers, David.
Re: where are the crontab files in Trixie?
On 29/02/2024 00:00, Kamil Jońca wrote: How precisely linger works? (what it starts? What not etc) I read about lingering some time ago, and I have had impression (wrong?) that it may conflict with my normal session. Multiple sessions may be started for a user: DM, ssh, VT logins. I am unsure what one you consider as your normal session. These sessions run withing single systemd user service.
Re: where are the crontab files in Trixie?
Andy Smith writes: > Hi, > > On Wed, Feb 28, 2024 at 04:47:59PM +0100, Kamil Jońca wrote: >> Andy Smith writes: >> > Once you enable lingering for a user, that user's timers will >> > trigger all the time. >> >> IIRC lingered user cannot be "normal" with session and so on. Am I >> wrong? > > How do you mean? On several machines I have linger enabled for my > main user, and timers run when I am not logged in. How precisely linger works? (what it starts? What not etc) I read about lingering some time ago, and I have had impression (wrong?) that it may conflict with my normal session. KJ
Re: where are the crontab files in Trixie?
Hi, On Wed, Feb 28, 2024 at 04:47:59PM +0100, Kamil Jońca wrote: > Andy Smith writes: > > Once you enable lingering for a user, that user's timers will > > trigger all the time. > > IIRC lingered user cannot be "normal" with session and so on. Am I > wrong? How do you mean? On several machines I have linger enabled for my main user, and timers run when I am not logged in. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
Re: where are the crontab files in Trixie?
Andy Smith writes: > Hi, > > On Wed, Feb 28, 2024 at 05:49:58AM +0100, Kamil Jońca wrote: >> With cron, regular user can set up his/her jobs wihtout using admin >> credentials, and these jobs will be triggered regardless of being logged >> in. Is it possible with systemd timers? > > Once you enable lingering for a user, that user's timers will > trigger all the time. IIRC lingered user cannot be "normal" with session and so on. Am I wrong? KJ
Re: where are the crontab files in Trixie?
Max Nikulin (12024-02-28): > I am in doubts if it is a task for cron. Wouldn't udev rules be better? Or even the good old simple way that still works: install modulename command... This command instructs modprobe to run your command instead of inserting the module in the kernel as normal. The command can be any shell command: this allows you to do any kind of complex processing you might wish. For example, if the module "fred" works better with the module "barney" already installed (but it doesn't depend on it, so modprobe won't automatically load it), you could say "install fred /sbin/modprobe barney; /sbin/modprobe --ignore-install fred", which would do what you wanted. Note the --ignore-install, which stops the second modprobe from running the same install command again. See also remove below. Regards, -- Nicolas George
Re: where are the crontab files in Trixie?
On 28/02/2024 10:35, David Wright wrote: In which case, I'd write the remaining cron line as: @reboot sleep 99 && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id I am in doubts if it is a task for cron. Wouldn't udev rules be better? https://stackoverflow.com/questions/442833/how-to-force-driver-to-device-match-in-linux/52943745#52943745 https://unix.stackexchange.com/questions/67936/attaching-usb-serial-device-with-custom-pid-to-ttyusb0-on-embedded/165845#165845 Moreover, to load and configure modules there are /etc/modprobe.d/ and /etc/modules. If it is a weird device that may appear either as 13b1:0039 (supported by brcmfmac accordingly to modinfo) and 13b1:0bdc, may it happen that it is possible to use e.g. usb-modeswitch to adjust which way the device tries to present itself?
Re: where are the crontab files in Trixie?
Hi, On Wed, Feb 28, 2024 at 05:49:58AM +0100, Kamil Jońca wrote: > With cron, regular user can set up his/her jobs wihtout using admin > credentials, and these jobs will be triggered regardless of being logged > in. Is it possible with systemd timers? Once you enable lingering for a user, that user's timers will trigger all the time. https://wiki.archlinux.org/title/Systemd/User#Automatic_start-up_of_systemd_user_instances I haven't yet found anything that I could do with cron that I can't do with systemd timers, though sometimes the behaviour of cron where it emails you the output (if any) is very convenient and is tricky (but not impossible) to replicate with systemd timers. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
Re: where are the crontab files in Trixie?
Hello, On Tue, Feb 27, 2024 at 02:58:13PM -0500, Greg Wooledge wrote: > I don't foresee real cron going away any time soon. If you today install bookworm base system and select no packages, the only reason why you get cron is because logrotate depends upon it. If you do not need logrotate then you can also remove cron, and nothing complains. It seems likely that at some point logrotate will become optional (because of journald) or that logrotate will get a systemd timer, at which point cron wouldn't be installed on a base install unless there is some other package dependency. On this list we already saw a post from someone who did not have cron installed. Initially I thought that was a rather bold modification by their hosting provider, but it turned out that they really did have no package that depended upon cron. So as far as Debian is concerned I do see it as fairly inevitable that cron soon doesn't get installed on many systems and increasingly becomes a curiosity, but since it will have to stick around until the last package stops shipping (only) a cron job, arguably it still remains in the archive for a very long time yet. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
Re: where are the crontab files in Trixie?
Gremlin writes: [...] > > https://wiki.archlinux.org/title/Systemd-networkd > https://wiki.archlinux.org/title/Wireless_bonding > > I am using systemd-networkd and systemd-resolved and have removed > Networkmanager, ifupdown and isc-dhcp. Also avahi, modemmanager, > openssh-sftp-server openssh-server and openssh-sk-helper Great. But I think that systemd is still not able to handle my config (described for example here https://lists.freedesktop.org/archives/systemd-devel/2022-May/047934.html ) Recently someone describes problem with proper routing of DNS questions, when he has VPN connection. > > They ain't needed For you. When comes to cron and systemd timers. With cron, regular user can set up his/her jobs wihtout using admin credentials, and these jobs will be triggered regardless of being logged in. Is it possible with systemd timers? KJ
Re: where are the crontab files in Trixie?
On Tue 27 Feb 2024 at 15:35:07 (+), Michael Kjörling wrote: > On 27 Feb 2024 10:15 -0500, from g...@extremeground.com (Gary Dale): > In this case you might even want the second to execute only when the > first completes _successfully_, so: > > @reboot /usr/sbin/modprobe brcmfmac && echo 13b1 0bdc > > /sys/bus/usb/drivers/brcmfmac/new_id I wondered whether that might cause any error message to be lost in normal booting output (assuming you've asked for it). > _That said_, if you want to load a module on boot, the generally > recommended way these days is to add it to a *.conf file in > /etc/modules-load.d. See modules-load.d(5) for details. The old way > was to add it to the file /etc/modules. In which case, I'd write the remaining cron line as: @reboot sleep 99 && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id where you can choose a better estimate than 99. > > Anyway, that got me down the rabbit hole to try to find where the crontab > > file is. > > Per-user crontabs are in /var/spool/cron/crontabs, or at least are in > Bookworm (and this has been the case for what feels like forever). > This is mentioned in the DIAGNOSTICS section of the crontab(1) man > page, as well as in the NOTES section of the cron(8) man page. If you lose track of where a crontab was originally generated from¹, the filename is in the second line of /var/spool/cron/crontabs/. Note that you won't see the first three lines of crontabs/ listed by crontab -l or at the top of the file edited by crontab -e because they're stripped out and reinserted by crontab². See the DEBIAN SPECIFIC section in man 1 crontab. ¹ Assuming you use crontab filename. Otherwise, the filename in crontabs/ will be of little interest. ² This behaviour can be overridden with CRONTAB_NOHEADER='N' Cheers, David.
Re: where are the crontab files in Trixie?
On Tue, Feb 27, 2024 at 10:12:11PM -0500, The Wanderer wrote: > On 2024-02-27 at 14:09, Gary Dale wrote: > > as does find / -name crontab > > Invoked how? In particular, as which user? > > Assuming that the crontab files are actually named literally 'crontab' > with no extra characters (perhaps by being stored one per directory), my > guess would be that this is because /var/spool/cron/crontabs is not > world-executable, and therefore most users won't be able to list its > contents. If you run that 'find' command as root, or as a user which is > in the group that owns the directory, you may see that the files show > up. > > (If they aren't literally named just 'crontab' verbatim, then you'd also > need to specify wildcards etc. in the find arguments, in order for it to > recognize them as being a valid match.) The only file named "crontab" is /etc/crontab. Per-user crontabs which live in /var/spool/cron/crontabs are named for their owner. hobbit:~$ sudo ls /var/spool/cron/crontabs greg If you really want to find where the files live, and you didn't happen to already know (approximately) where they are, and if you haven't been reading this mailing list thread, then you could try reading cron(8): NOTES cron searches its spool area (/var/spool/cron/crontabs) for crontab files (which are named after accounts in /etc/passwd); crontabs found are loaded into memory. Note that crontabs in this directory should not be accessed directly - the crontab command should be used to access and update them. This isn't hard to find. Seriously. Even if you tried crontab(1) first, it's in there too: DESCRIPTION crontab is the program used to install, deinstall or list the tables used to drive the cron(8) daemon in Vixie Cron. Each user can have theirowncrontab,andthoughthesearefiles in /var/spool/cron/crontabs, they are not intended to be edited directly. The only place it *isn't* is crontab(5), but hey, two out of three ain't bad, as someone once sang.
Re: where are the crontab files in Trixie?
On 2024-02-27 at 14:09, Gary Dale wrote: > On 2024-02-27 10:26, The Wanderer wrote: > >> On 2024-02-27 at 10:15, Gary Dale wrote: >> >>> Anyway, that got me down the rabbit hole to try to find where the >>> crontab file is. >>> >>>ls -l /root/cron* >>> ls: cannot access '/root/cron*': No such file or directory >>> >>> also >>> >>> # whereis crontab >>> crontab: /usr/bin/crontab /etc/crontab /usr/share/man/man1/crontab.1.gz >>> /usr/share/man/man5/crontab.5.gz >>> >>> so it's not in the location that you'd expect. >> >> I'm not sure whereis is suitable for finding things like this. As >> its man page states, it's for finding "the binary, source, and >> manual page files for a command" - not the data files which the >> command may work with. > > locate crontab also fails to find it, That would be because updatedb is configured to exclude /var/spool and everything underneath it. Look at /etc/updatedb.conf; you'll probably find that PRUNEPATHS is set to include /var/spool. (It is on my system, and I'm reasonably certain that it's by default.) > as does find / -name crontab Invoked how? In particular, as which user? Assuming that the crontab files are actually named literally 'crontab' with no extra characters (perhaps by being stored one per directory), my guess would be that this is because /var/spool/cron/crontabs is not world-executable, and therefore most users won't be able to list its contents. If you run that 'find' command as root, or as a user which is in the group that owns the directory, you may see that the files show up. (If they aren't literally named just 'crontab' verbatim, then you'd also need to specify wildcards etc. in the find arguments, in order for it to recognize them as being a valid match.) >>> Nor can I find it in /etc/. The various cron files there don't >>> contain the lines I;m looking for. >>> >>> Can anyone explain how Trixie is handling crontabs now? >> >> The first paragraph of crontab(1) states: >> Each user can have their own crontab, and though these are files in /var/spool/cron/crontabs,they are not intended to be edited directly. >> >> So, while I don't use per-user crontabs myself and so don't have >> experience with this personally, I would suggest looking in that >> directory - but not necessarily editing the files there, except >> via 'crontab -e' as you have already done. > > Thanks. I missed that when I was reading the comments. I need to > enlarge the text more, I guess. It took a bit of careful looking for me, too, even when I was fairly sure something like this would be in there. -- The Wanderer The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man. -- George Bernard Shaw signature.asc Description: OpenPGP digital signature
Re: where are the crontab files in Trixie?
On 2/27/24 14:58, Greg Wooledge wrote: On Tue, Feb 27, 2024 at 12:52:33PM -0700, Charles Curley wrote: On Tue, 27 Feb 2024 14:13:49 -0500 Jeffrey Walton wrote: The debian wiki suggests that the handling of cron/anacron is evolving. That sounds like a euphemism for "being killed off" by Systemd and its timers. These days cron and anacron are run as services/timers by systemd. root@hawk:~# systemctl list-units '*cron*' UNITLOAD ACTIVE SUB DESCRIPTION cron.serviceloaded active running Regular background program processing daemon anacron.timer loaded active waiting Trigger anacron every hour nextcloudcron.timer loaded active waiting Run Nextcloud cron.php every 5 minutes Systemd timers are designed to replace crontabs, but that's not what cron.service is. cron.service runs an actual cron daemon. hobbit:~$ systemctl status cron ● cron.service - Regular background program processing daemon Loaded: loaded (/lib/systemd/system/cron.service; enabled; preset: enabled) Active: active (running) since Sat 2024-02-17 20:45:06 EST; 1 week 2 days > Docs: man:cron(8) Main PID: 789 (cron) Tasks: 1 (limit: 18738) Memory: 21.9M CPU: 5.275s CGroup: /system.slice/cron.service └─789 /usr/sbin/cron -f hobbit:~$ ps -fp 789 UID PIDPPID C STIME TTY TIME CMD root 789 1 0 Feb17 ?00:00:01 /usr/sbin/cron -f I don't foresee real cron going away any time soon. If systemd wants to create an alternative to it, that's fine, but people know cron, they like cron, and they *trust* cron. Systemd timers don't have any of those benefits yet. I purged cron from my systems and I use systemd-timers -- Hindi madali ang maging ako
Re: where are the crontab files in Trixie?
On 2/27/24 14:33, Gary Dale wrote: On 2024-02-27 14:13, Jeffrey Walton wrote: On Tue, Feb 27, 2024 at 2:12 PM Gary Dale wrote: On 2024-02-27 10:25, Kushal Kumaran wrote: On Tue, Feb 27 2024 at 10:15:59 AM, Gary Dale wrote: [...] Can anyone explain how Trixie is handling crontabs now? This behavior has existed forever. I'm on bookworm, though, so no idea if anything is changing in trixie. The debian wiki suggests that the handling of cron/anacron is evolving. That sounds like a euphemism for "being killed off" by Systemd and its timers. Jeff There are a lot of things going on these days that don't seem quite ready for prime time. Examples include systemd networking, which remains woefully ill-equipped to deal with bonding and wifi LOL https://wiki.archlinux.org/title/Systemd-networkd https://wiki.archlinux.org/title/Wireless_bonding I am using systemd-networkd and systemd-resolved and have removed Networkmanager, ifupdown and isc-dhcp. Also avahi, modemmanager, openssh-sftp-server openssh-server and openssh-sk-helper They ain't needed Wayland may have some good things to say about it but when I try it, it messes up my desktop. I have my desktop scaled to 150% to help with my old eyes, but Wayland doesn't seem to apply it to text, which is where I really need it. I'm hoping Plasma 6 will address the Wayland issues at least. Using wayland with lxde ii libqt5waylandclient5:arm64 5.15.8-2 arm64QtWayland client library ii libqt5waylandcompositor5:arm64 5.15.8-2 arm64QtWayland compositor library ii libva-wayland2:arm64 2.17.0-1 arm64Video Acceleration (VA) API for Linux -- Wayland runtime ii libwayland-client0:arm64 1.21.0-1 arm64wayland compositor infrastructure - client library ii libwayland-cursor0:arm64 1.21.0-1 arm64wayland compositor infrastructure - cursor library ii libwayland-egl1:arm641.21.0-1 arm64wayland compositor infrastructure - EGL library ii libwayland-server0:arm64 1.21.0-1 arm64wayland compositor infrastructure - server library ii libwlroots11:arm64 0.16.0-2~bpo11+1~rpt13 arm64Modular wayland compositor library - shared library ii qtwayland5:arm64 5.15.8-2 arm64QtWayland platform plugin ii xwayland 2:22.1.9-1 arm64X server for running X clients under Wayland ii wayfire 0.7.5-1~bpo11+1~rpt33 arm643D Wayland compositor ii wayvnc 0.8.0-rc0-2 arm64VNC server for wlroots-based Wayland compositors ii xwayland 2:22.1.9-1 arm64X server for running X clients under Wayland ii lxde-common 0.99.2-4 all LXDE common configuration files ii lxde-core11+rpt1 all metapackage for the LXDE core ii lxde-icon-theme 0.5.1-2.1 all LXDE standard icon theme ii openbox-lxde-session 0.99.2-4 all LXDE session manager and configuration files -- If it ain't broke, FIX IT!
Re: where are the crontab files in Trixie?
On Tue, Feb 27, 2024 at 12:52:33PM -0700, Charles Curley wrote: > On Tue, 27 Feb 2024 14:13:49 -0500 > Jeffrey Walton wrote: > > > > The debian wiki suggests that the handling of cron/anacron is > > > evolving. > > > > That sounds like a euphemism for "being killed off" by Systemd and > > its timers. > > These days cron and anacron are run as services/timers by systemd. > > root@hawk:~# systemctl list-units '*cron*' > UNITLOAD ACTIVE SUB DESCRIPTION > > cron.serviceloaded active running Regular background program > processing daemon > anacron.timer loaded active waiting Trigger anacron every hour > nextcloudcron.timer loaded active waiting Run Nextcloud cron.php every 5 > minutes Systemd timers are designed to replace crontabs, but that's not what cron.service is. cron.service runs an actual cron daemon. hobbit:~$ systemctl status cron ● cron.service - Regular background program processing daemon Loaded: loaded (/lib/systemd/system/cron.service; enabled; preset: enabled) Active: active (running) since Sat 2024-02-17 20:45:06 EST; 1 week 2 days > Docs: man:cron(8) Main PID: 789 (cron) Tasks: 1 (limit: 18738) Memory: 21.9M CPU: 5.275s CGroup: /system.slice/cron.service └─789 /usr/sbin/cron -f hobbit:~$ ps -fp 789 UID PIDPPID C STIME TTY TIME CMD root 789 1 0 Feb17 ?00:00:01 /usr/sbin/cron -f I don't foresee real cron going away any time soon. If systemd wants to create an alternative to it, that's fine, but people know cron, they like cron, and they *trust* cron. Systemd timers don't have any of those benefits yet.
Re: where are the crontab files in Trixie?
On Tue, 27 Feb 2024 14:13:49 -0500 Jeffrey Walton wrote: > > The debian wiki suggests that the handling of cron/anacron is > > evolving. > > That sounds like a euphemism for "being killed off" by Systemd and > its timers. These days cron and anacron are run as services/timers by systemd. root@hawk:~# systemctl list-units '*cron*' UNITLOAD ACTIVE SUB DESCRIPTION cron.serviceloaded active running Regular background program processing daemon anacron.timer loaded active waiting Trigger anacron every hour nextcloudcron.timer loaded active waiting Run Nextcloud cron.php every 5 minutes LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB= The low-level unit activation state, values depend on unit type. 3 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'. root@hawk:~# -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
Re: where are the crontab files in Trixie?
On 2024-02-27 14:13, Jeffrey Walton wrote: On Tue, Feb 27, 2024 at 2:12 PM Gary Dale wrote: On 2024-02-27 10:25, Kushal Kumaran wrote: On Tue, Feb 27 2024 at 10:15:59 AM, Gary Dale wrote: [...] Can anyone explain how Trixie is handling crontabs now? This behavior has existed forever. I'm on bookworm, though, so no idea if anything is changing in trixie. The debian wiki suggests that the handling of cron/anacron is evolving. That sounds like a euphemism for "being killed off" by Systemd and its timers. Jeff There are a lot of things going on these days that don't seem quite ready for prime time. Examples include systemd networking, which remains woefully ill-equipped to deal with bonding and wifi. Wayland may have some good things to say about it but when I try it, it messes up my desktop. I have my desktop scaled to 150% to help with my old eyes, but Wayland doesn't seem to apply it to text, which is where I really need it. I'm hoping Plasma 6 will address the Wayland issues at least.
Re: where are the crontab files in Trixie?
On Tue, Feb 27, 2024 at 2:12 PM Gary Dale wrote: > > On 2024-02-27 10:25, Kushal Kumaran wrote: > > On Tue, Feb 27 2024 at 10:15:59 AM, Gary Dale > > wrote: > >> [...] > >> Can anyone explain how Trixie is handling crontabs now? > > This behavior has existed forever. I'm on bookworm, though, so no idea > > if anything is changing in trixie. > The debian wiki suggests that the handling of cron/anacron is evolving. That sounds like a euphemism for "being killed off" by Systemd and its timers. Jeff
Re: where are the crontab files in Trixie?
On 2024-02-27 10:32, Greg Wooledge wrote: On Tue, Feb 27, 2024 at 10:15:59AM -0500, Gary Dale wrote: I'm running Debian/Trixie on an AMD64 system. I have an old wifi adapter that Linux has problems with that works once I run: /usr/sbin/modprobe brcmfmac echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id However when I add those lines to the root's crontab using # crontab -e as @reboot /usr/sbin/modprobe brcmfmac @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id the second line fails. I get an e-mail stating "/bin/sh: 1: cannot create /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" Having two separate @reboot lines might run them both in parallel, rather than sequentially. It might be better to combine them into one shell command, or one script. Something like this, perhaps: @reboot /usr/sbin/modprobe brcmfmac && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id Or put the commands into a shell script, then run the script from crontab. Yep. That works. Thanks.
Re: where are the crontab files in Trixie?
On 2024-02-27 10:25, Kushal Kumaran wrote: On Tue, Feb 27 2024 at 10:15:59 AM, Gary Dale wrote: I'm running Debian/Trixie on an AMD64 system. I have an old wifi adapter that Linux has problems with that works once I run: /usr/sbin/modprobe brcmfmac echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id However when I add those lines to the root's crontab using # crontab -e as @reboot /usr/sbin/modprobe brcmfmac @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id the second line fails. I get an e-mail stating "/bin/sh: 1: cannot create /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" I'm not sure if the modprobe is working or if the module is being loaded without it. It's likely that debian detects the need for the module and loads it. Is it possible that the command is being run before the module is loaded. Consider putting both into a single command, perhaps by writing a script that does both things. Anyway, that got me down the rabbit hole to try to find where the crontab file is. ls -l /root/cron* ls: cannot access '/root/cron*': No such file or directory also # whereis crontab crontab: /usr/bin/crontab /etc/crontab /usr/share/man/man1/crontab.1.gz /usr/share/man/man5/crontab.5.gz so it's not in the location that you'd expect. Nor can I find it in /etc/. The various cron files there don't contain the lines I;m looking for. Editing/creating crontab files using "crontab -e" creates it in /var/spool/cron/crontabs. Can anyone explain how Trixie is handling crontabs now? This behavior has existed forever. I'm on bookworm, though, so no idea if anything is changing in trixie. The debian wiki suggests that the handling of cron/anacron is evolving.
Re: where are the crontab files in Trixie?
On 2024-02-27 10:26, The Wanderer wrote: On 2024-02-27 at 10:15, Gary Dale wrote: Anyway, that got me down the rabbit hole to try to find where the crontab file is. ls -l /root/cron* ls: cannot access '/root/cron*': No such file or directory also # whereis crontab crontab: /usr/bin/crontab /etc/crontab /usr/share/man/man1/crontab.1.gz /usr/share/man/man5/crontab.5.gz so it's not in the location that you'd expect. I'm not sure whereis is suitable for finding things like this. As its man page states, it's for finding "the binary, source, and manual page files for a command" - not the data files which the command may work with. locate crontab also fails to find it, as does find / -name crontab Nor can I find it in /etc/. The various cron files there don't contain the lines I;m looking for. Can anyone explain how Trixie is handling crontabs now? The first paragraph of crontab(1) states: Each user can have their own crontab, and though these are files in /var/spool/cron/crontabs,they are not intended to be edited directly. So, while I don't use per-user crontabs myself and so don't have experience with this personally, I would suggest looking in that directory - but not necessarily editing the files there, except via 'crontab -e' as you have already done. Thanks. I missed that when I was reading the comments. I need to enlarge the text more, I guess.
Re: where are the crontab files in Trixie?
On 27 Feb 2024 10:15 -0500, from g...@extremeground.com (Gary Dale): > However when I add those lines to the root's crontab using # crontab -e as > > @reboot /usr/sbin/modprobe brcmfmac > @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > the second line fails. I get an e-mail stating "/bin/sh: 1: cannot create > /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" Probably a timing issue. "@reboot" crontab entries execute fairly early (I think it really means "when the cron daemon starts"), and among crontab entries with the same execution time, I do believe that execution order is unspecified and execution quite possibly is parallelized. Since redirection is done by the shell, and command invocation is also done by the shell, if the two start executing at the same moment and execute perfectly in parallel, it seems very likely that the shell would conclude that the path into which you want to redirect stdout is nonexistent before modprobe has even finished loading, let alone finished loading the module. If two commands must be executed in sequence, either set up the crontab entries so that the execution times cannot conflict, or separate the commands with semicolons: @reboot /usr/sbin/modprobe brcmfmac; echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id In this case you might even want the second to execute only when the first completes _successfully_, so: @reboot /usr/sbin/modprobe brcmfmac && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id _That said_, if you want to load a module on boot, the generally recommended way these days is to add it to a *.conf file in /etc/modules-load.d. See modules-load.d(5) for details. The old way was to add it to the file /etc/modules. > Anyway, that got me down the rabbit hole to try to find where the crontab > file is. Per-user crontabs are in /var/spool/cron/crontabs, or at least are in Bookworm (and this has been the case for what feels like forever). This is mentioned in the DIAGNOSTICS section of the crontab(1) man page, as well as in the NOTES section of the cron(8) man page. -- Michael Kjörling https://michael.kjorling.se “Remember when, on the Internet, nobody cared that you were a dog?”
Re: where are the crontab files in Trixie?
On Tue, Feb 27, 2024 at 10:15:59AM -0500, Gary Dale wrote: > I'm running Debian/Trixie on an AMD64 system. I have an old wifi adapter > that Linux has problems with that works once I run: > > /usr/sbin/modprobe brcmfmac > echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > However when I add those lines to the root's crontab using # crontab -e as > > @reboot /usr/sbin/modprobe brcmfmac > @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > the second line fails. I get an e-mail stating "/bin/sh: 1: cannot create > /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" Having two separate @reboot lines might run them both in parallel, rather than sequentially. It might be better to combine them into one shell command, or one script. Something like this, perhaps: @reboot /usr/sbin/modprobe brcmfmac && echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id Or put the commands into a shell script, then run the script from crontab.
Re: where are the crontab files in Trixie?
On 2024-02-27 at 10:15, Gary Dale wrote: > Anyway, that got me down the rabbit hole to try to find where the > crontab file is. > > ls -l /root/cron* > ls: cannot access '/root/cron*': No such file or directory > > also > > # whereis crontab > crontab: /usr/bin/crontab /etc/crontab /usr/share/man/man1/crontab.1.gz > /usr/share/man/man5/crontab.5.gz > > so it's not in the location that you'd expect. I'm not sure whereis is suitable for finding things like this. As its man page states, it's for finding "the binary, source, and manual page files for a command" - not the data files which the command may work with. > Nor can I find it in /etc/. The various cron files there don't > contain the lines I;m looking for. > Can anyone explain how Trixie is handling crontabs now? The first paragraph of crontab(1) states: >> Each user can have their own crontab, and though these are files in >> /var/spool/cron/crontabs,they are not intended to be edited >> directly. So, while I don't use per-user crontabs myself and so don't have experience with this personally, I would suggest looking in that directory - but not necessarily editing the files there, except via 'crontab -e' as you have already done. -- The Wanderer The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man. -- George Bernard Shaw signature.asc Description: OpenPGP digital signature
Re: where are the crontab files in Trixie?
On Tue, Feb 27 2024 at 10:15:59 AM, Gary Dale wrote: > I'm running Debian/Trixie on an AMD64 system. I have an old wifi > adapter that Linux has problems with that works once I run: > > /usr/sbin/modprobe brcmfmac > echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > However when I add those lines to the root's crontab using # crontab -e as > > @reboot /usr/sbin/modprobe brcmfmac > @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id > > the second line fails. I get an e-mail stating "/bin/sh: 1: cannot > create /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" > > I'm not sure if the modprobe is working or if the module is being > loaded without it. It's likely that debian detects the need for the > module and loads it. > Is it possible that the command is being run before the module is loaded. Consider putting both into a single command, perhaps by writing a script that does both things. > Anyway, that got me down the rabbit hole to try to find where the > crontab file is. > > ls -l /root/cron* > ls: cannot access '/root/cron*': No such file or directory > > also > > # whereis crontab > crontab: /usr/bin/crontab /etc/crontab > /usr/share/man/man1/crontab.1.gz /usr/share/man/man5/crontab.5.gz > > so it's not in the location that you'd expect. Nor can I find it in > /etc/. The various cron files there don't contain the lines I;m > looking for. > Editing/creating crontab files using "crontab -e" creates it in /var/spool/cron/crontabs. > > > Can anyone explain how Trixie is handling crontabs now? This behavior has existed forever. I'm on bookworm, though, so no idea if anything is changing in trixie. -- regards, kushal
where are the crontab files in Trixie?
I'm running Debian/Trixie on an AMD64 system. I have an old wifi adapter that Linux has problems with that works once I run: /usr/sbin/modprobe brcmfmac echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id However when I add those lines to the root's crontab using # crontab -e as @reboot /usr/sbin/modprobe brcmfmac @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id the second line fails. I get an e-mail stating "/bin/sh: 1: cannot create /sys/bus/usb/drivers/brcmfmac/new_id: Directory nonexistent" I'm not sure if the modprobe is working or if the module is being loaded without it. It's likely that debian detects the need for the module and loads it. Anyway, that got me down the rabbit hole to try to find where the crontab file is. ls -l /root/cron* ls: cannot access '/root/cron*': No such file or directory also # whereis crontab crontab: /usr/bin/crontab /etc/crontab /usr/share/man/man1/crontab.1.gz /usr/share/man/man5/crontab.5.gz so it's not in the location that you'd expect. Nor can I find it in /etc/. The various cron files there don't contain the lines I;m looking for. However, running crontab -e as root definitely shows the file I expect to see. Specifically: # Edit this file to introduce tasks to be run by cron. # # Each task to run has to be defined through a single line # indicating with different fields when the task will be run # and what command to run for the task # # To define the time you can provide concrete values for # minute (m), hour (h), day of month (dom), month (mon), # and day of week (dow) or use '*' in these fields (for 'any'). # # Notice that tasks will be started based on the cron's system # daemon's notion of time and timezones. # # Output of the crontab jobs (including errors) is sent through # email to the user the crontab file belongs to (unless redirected). # # For example, you can run a backup of all your user accounts # at 5 a.m every week with: # 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/ # # For more information see the manual pages of crontab(5) and cron(8) # # m h dom mon dow command @reboot /usr/sbin/modprobe brcmfmac @reboot echo 13b1 0bdc > /sys/bus/usb/drivers/brcmfmac/new_id Looking at systemd-timers doesn't show anything obvious either. Can anyone explain how Trixie is handling crontabs now?
