X-Git-Url: http://git.grml.org/?a=blobdiff_plain;f=grml_tips;h=66f46a541a30d81d6dc2e36d540779e78c06ad58;hb=42d529ed4951169521e868ba6bd35abc70de8c1a;hp=2b150a508e03ae059ac596f8f32ed349f359172b;hpb=e177ed05e5d493245466025bb745d299cda3bead;p=grml-tips.git diff --git a/grml_tips b/grml_tips index 2b150a5..66f46a5 100644 --- a/grml_tips +++ b/grml_tips @@ -43,12 +43,6 @@ Configure network: # grml-network -- -Boot grml via network: - -# grml-terminalserver - -See: man grml-terminalserver + http://grml.org/terminalserver/ --- Deactivate error correction of zsh: % NOCOR=1 zsh @@ -663,7 +657,7 @@ to get a list of all supported trees -- Transfer your SSH public key to another host: -% ssh-keygen # if you don't have a key yet +% ssh-keygen # ssh-keygen / ssh-key-gen: if you don't have a key yet [...] % ssh-copy-id -i ~/.ssh/id_rsa.pub user@remote-system or @@ -2652,10 +2646,13 @@ and where grml is running: Then booting your client(s) via PXE should work without any further work. + +See: man grml-terminalserver + http://grml.org/terminalserver/ -- Debugging SSL communications: -% openssl s_client -connect server.adress:993 +% openssl s_client -connect server.adress:993 > output_file +% openssl x509 -noout -text -in output_file or @@ -2847,3 +2844,161 @@ Enable syntax highlighting in nano: Just uncomment the include directives for your respective language at the bottom of the file /etc/nanorc -- +Create netboot package for grml-terminalserver: + +# sh /usr/share/doc/grml-terminalserver/examples/create-netboot +-- +To boot grml via network (PXE) check out grml-terminalserver: + +# grml-terminalserver + +See http://grml.org/terminalserver/ for more details. +-- +Rotate pictures: + +Using the 'Orientation' tag of the Exif header, rotate +the image so that it is upright: +% jhead -autorot *.jpg + +Manually rotate a picture: +% convert -rotate 270 input.jpg output.jpg +-- +Rename files based on the information inside their exif header: + +% jhead -n%Y-%m-%d_%Hh%M_%f *.jpg + +This will rename a file named img_2071.jpg to something like: + +2007-08-17_10h38_img_2071.jpg + +if it was shot at 10:38 o'clock on 2007-08-17 (according to +the information inside the exif header). +-- +Calculate network / netmask: + +Usage examples: +% ipcalc 10.0.0.28 255.255.255.0 +% ipcalc 10.0.0.0/24 +-- +Blacklist a kernel module: + +# blacklist + +-> running 'blacklist hostap_cs' for example will generate an +entry like this in /etc/modprobe.d/grml: + +blacklist hostap_cs +alias hostap_cs off + +To remove the module from the blacklist again just invoke: + +# unblacklist + +or manually remove the entry from /etc/modprobe.d/grml. +-- +Create a Debian package of a perl module: + +% dh-make-perl --cpan Acme::Smirch --build +-- +The Magic SysRq Keys (SysReq or Sys Req, short for System Request): + +To reboot your system using the SysRq keys just hold down the Alt and +SysRq (Print Screen) key while pressing the keys REISUB ("Raising +Elephants Is So Utterly Boring"). + +R = take the keyboard out of raw mode +E = terminates all processes (except init) +I = kills all processes (except init) +S = synchronizes the disk(s) +U = remounts all filesystems read-only +B = reboot the system + +Notice: use O instead of B for poweroff. + +Or write the sequence to /proc/sysrq-trigger instead: + +# for i in r e i s u b ; do echo $i > /proc/sysrq-trigger ; done + +To enable or disable SysRq calls: + +# echo 0 > /proc/sys/kernel/sysrq +# echo 1 > /proc/sys/kernel/sysrq + +See http://en.wikipedia.org/wiki/Magic_SysRq_key for more details. +-- +Memtest / memcheck: + +Just boot your grml Live-CD with "memtest" to execute a memcheck/memtest +with Memtest86+. +-- +Tunnel TCP-Traffic through DNS using dns2tcp: + +Server-side: +~~~~~~~~~~~~ +1. Create necessary DNS-Records: +dnstun.example.com. 3600 IN NS host.example.com. +dnstun.example.com. 3600 IN A 192.168.1.1 +host.example.com. 3600 IN A 192.168.1.1 + +2. Configure dns2tcpd on host.example.com.: +# cat /etc/dns2tcpd.conf +listen = 192.168.1.1 #the ip dns2tcpd should listen on +port = 53 #" port " " " " +user = nobody +chroot = /tmp +domain = dnstun.example.com. # the zone as specified inside dns +ressources = ssh:127.0.0.1:22 # available resources + +3. Start the daemon: +# cat > /etc/default/dns2tcp << EOF +# Set ENABLED to 1 if you want the init script to start dns2tcpd. +ENABLED=1 +USER=nobody +EOF +# /etc/init.d/dns2tcp start + +Client-side: +~~~~~~~~~~~~ +You have two possibilities: +- Use the DNS inside your network (DNS must allow resolving for external domains) +# grep nameserver /etc/resolv.conf +nameserver 172.16.42.1 +# dns2tcpc -z dnstun.example.com 172.16.42.1 +Available connection(s) : + ssh +# dns2tcpc -r ssh -l 2222 -z dnstun.example.com 172.16.42.1 & +Listening on port : 2222 +# ssh localhost -p 2222 +user@host.example.com:~# + +- Directly contact the endpoint (port 53 UDP must be allowed outgoing) +# dns2tcpc -z dnstun.example.com dnstun.example.com +Available connection(s) : + ssh +# dns2tcpc -r ssh -l 2222 -z dnstun.example.com dnstun.example.com & +Listenning on port : 2222 +# ssh localhost -p 2222 +user@host.example.com:~# + +Notice: using 'ssh -D 8080 ..' you will get a socks5-proxy listening on +localhost:8080 which you can use to tunnel everything through your "dns-uplink". +-- +Configure a MadWifi device for adhoc mode: + +Disable the autocreation of athX devices: +# echo "options ath_pci autocreate=none" > /etc/modprobe.d/madwifi + +Remove the autocreated device for now: +# wlanconfig ath0 destroy + +Configuration in /etc/network/interfaces: + +iface ath0 inet static + madwifi-base wifi0 + madwifi-mode adhoc + ... + +Hints: + - Do not use interface names without ending 0 (otherwise startup fails). + - Only chooss unique names for interfaces. +--