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Questions tagged [hook]

The tag has no usage guidance.

-1
votes
1answer
58 views

Capture output of a command, process it and ONLY then output to terminal

I would like to capture the stdout (as sent to a terminal), and perform some processing after it is output on the terminal (for the user). I want to know how to grab the output, process and make ...
3
votes
1answer
86 views

How to use debuild hooks (--signing-hook-foo etc)

The man page isn't clear on that. How would I use a signing hook? Especially using the parameter without the config file. What is the meaning of foo in the documentation? For example in --signing-...
0
votes
1answer
20 views

Thunderbird overloads my HDD in large operations, what to do?

If I do operations in Thunderbird with many (thousands of) mails, I hear a crashing voice from my HDDs. It sounds really not beautiful. It happens only if I do something with a lot of mails (for ...
2
votes
0answers
57 views

how to run a script before execute a dbus-send command?

I have the following problem: on lubuntu 16.04 I can send the laptop to sleep (suspend on RAM) using a hook script to switch to a virtual teminal before to suspend and reswitching out from a vt after ...
2
votes
0answers
129 views

Is there any hook for isc-dhcp-server returning the DHCPACK to client? [closed]

I would like to run a script in the server after the isc-dhcp-server send the DHCPACK packet to client. Only now I get it solution is that running a script to retrieve the dhcp log, but it is not ...
3
votes
0answers
425 views

Hooking sys_execve on Linux kernel 4.6 or higher

Kernels lower than 4.6 use assembly stubs to harden the hooking of critical system calls like fork, clone, exec etc. Particularly speaking for execve, the following snippet from Kernel-4.5 shows entry ...
0
votes
1answer
152 views

Follow files execution by a kernel module [closed]

I'm currently doing some project of secure the kernel with syscall hooking and logs... Now I've done hooking read, and socket system calls, and when I tried to do the same thing with execve (to follow ...
0
votes
0answers
587 views

Change env variable based off current directory - hook into cd command somehow? [duplicate]

Is there a way on *nix machines, to change the value of an environment variable depending on the current working directory? I am working on an NPM/Node.js module. Basically what I want to do, is ...
2
votes
2answers
781 views

Copy kernel images after kernel update

I am using ArchLinux on a machine using systemd-boot and UEFI to boot the system. When I receive a new kernel update, the new kernel get's created in my /boot , but the UEFI-Boot Partition is mounted ...
4
votes
3answers
418 views

Inspect IO operations on FreeBSD system

I would know is there any way to inspect/intercept IO operations on FreeBSD. Like ktrace but if I don't know the process (which takes some big time for example).
1
vote
2answers
460 views

When gitlab says make a file executable what exactly do they mean?

Gitlab says "Make the hook file executable and make sure it's owned by git" , but I read here that a file can be executable by owner, group, world. So which one do they mean? Right now I am ...
1
vote
1answer
691 views

Proxmox hook for VMs

We have Proxmox installation. We want to execute a command after new VM was added. It is required for QEMU port redirection since setting redir option is not avaialble on GUI: qm set 102 -args "--...
1
vote
0answers
865 views

'gnome-screensaver-command -l' doesn't work when called from '/etc/pm/sleep.d'-script

I am using Archlinux and trying to let my notebook lock the screen via the instructions given on wiki.archlinux.org before it suspends. Calling gnome-screensaver-command -l only locks my screen, when ...
1
vote
0answers
417 views

How to change the order of HOOKS in debian iniramfs configuration?

Hello I installed Archlinux to learn and now I'm insalling Debian but the initramfs setup is quite different from the mkinitcpio from Arch. My question is : where do I find the order in which the ...
0
votes
0answers
35 views

How do I hook an application and find out what files it writes while running? [duplicate]

I'm not sure how to exactly word this question, because my searching hasn't yielded anything that describes my situation what I'm looking for. Say my friend writes an application and sends it to me ...
0
votes
1answer
2k views

dhclient enter/exit hooks to update resolv.conf

I would want to append the below line to resolv.conf of all servers in our aws env and make sure it doesn't get overwritten options timeout:1 attempts:1 rotate I came across dhclient enter and exit ...
3
votes
0answers
174 views

Any way to specify process to call on Linux when OOM activates?

On my embedded system I'd like to record when the system OOM killer actives, e.g. by setting an env. variable in u-boot. Is there any way to specify a hook function to call on the OOM event?
1
vote
0answers
50 views

Can I add a hook in openbox

The idea is to set per application keyboard shortcut. A hook after that application window get focus and before it's lost focus is needed to switch the keybinding. This question is related to https://...
8
votes
5answers
2k views

How to run a command before download with apt-get?

How can I run a command before apt-get starts to download a package? I know about the dpkg pre-invoke hook ( hook a script to apt-get ), but that seems to be run after the download. $ apt-get update ...
1
vote
2answers
212 views

dhcp without dns: ping `hostname` not working. Auto add hostname to /etc/hosts?

On RHEL 6.5 how to make my own hostname locally resolvable, if my ip address is dynamic and not registered in DNS? I know, it's possible to add dhcp hook scripts. Is there a similar way to hook the ...
1
vote
1answer
521 views

Dpkg env variable DPKG_HOOK_ACTION is not set in hook script

According to man dpkg I can use DPKG_HOOK_ACTION to get the current dpkg action being run in my dpkg hook script --pre-invoke=command --post-invoke=command Set an invoke hook command to be run ...
10
votes
3answers
1k views

How can I run a command in bash after any change in $PWD?

zsh provides some nice hook functions, including chpwd for running a function after the user changes directories. # zsh only function greet() { echo 'hi'; } chpwd_functions+=("greet") cd .. # hi ...
1
vote
1answer
3k views

gphoto2 hook scripts - a guide?

I posted this on raspberrypi.stackexchange but was directed here. I'm new to Linux / Unix, and I'm trying to get a tether / display script going with gphoto2. gphoto2 --capture-tethered --hook-...
4
votes
2answers
611 views

Falling to git checkout on non-found bash commands

When I type (in bash) a command which linux does not find, it usually does something like this: $ x x: command not found but when I type a command which is not found but which is similar in some ...
5
votes
4answers
1k views

Run command when temperature exceeds threshold, without daemon

I need to run a specific command if my laptop gets too hot (for example, send a STOP signal to Firefox or Virtualbox in order to prevent my laptop from shutting down violently and damaging my hard ...
6
votes
2answers
3k views

Encrypt hook in mkinitcpio.conf for full system encryption USB drive Arch install

I have installed Arch Linux on a USB drive with full system encryption using LUKS. The Arch wiki as usual walked me through almost everything. The only issue I ran into was using setting up the hooks ...
1
vote
1answer
1k views

Forcing keys to run bash scripts

Is it possible to define bash scripts for all keys on keyboard so that by pressing any key the bash script for that key will be run? The scripts may do anything, for instance they may save the key ...
1
vote
0answers
855 views

Can I install a sync completion hook with rsync daemon?

Like hooks in svn or git, can I install a server-side hook script for rsync daemon? For sync completion event. I am using FreeBSD9/rsyncd.
3
votes
1answer
2k views

Set environment variable for all of tmux shells when gnome-sessions gets restarted

To solve this problem, I need to set the environment variable DBUS_SESSION_BUS_ADDRESS for all shells inside tmux every time I restart gnome without restarting tmux (this is often). How can I best ...
1
vote
1answer
1k views

Trigger action each time a file is modified [duplicate]

Possible Duplicate: Can a bash script be hooked to a file? Is it possible to mount a mechanism to a file to perform an action (e.g. mark the change in some log file and such) each time the file ...
1
vote
1answer
1k views

How to preload my .so every time an application executes?

I've successfully used a hook under Linux with this article: http://hackerboss.com/overriding-system-functions-for-fun-and-profit/ Now I want to make my .so file load every time espeak loads up, no ...
7
votes
3answers
7k views

How to execute a script on gdm login automatically for all users?

What file should I modify to execute some instructions when any user logs in through gdm? I tried /etc/bashrc but that is executed ony when starting bash (and each time an xterm is open). I'd like to ...
1
vote
0answers
252 views

How can I make scripts run when a file/directory changes in Linux (like Mac OS X’s launchd)? [duplicate]

Possible Duplicate: Can a bash script be hooked to a file? On Mac OS X, there’s a handy daemon called launchd which (amongst other things) allows you to have scripts run when files or directories ...
14
votes
2answers
7k views

Ssh login hook?

Is there a way to run a script/command every time a user connects using ssh? Can it be configured globally (i.e run the script when any user login)? I came across this question on Identica, but there ...
32
votes
3answers
4k views

Can a bash script be hooked to a file?

I want a script to sleep unless a certain file is modifed/deleted (or a file created in a certain directory, or ...). Can this be achieved in some elegant way? The simplest thing that comes to my mind ...