NonStandardModel's questions

I have seen some messages mentioning "random read" during the boot process, so I went and checked dmesg and found these lines:

[ 7.563793] random: init: uninitialized urandom read (12 bytes read, 48 bits of entropy available)

[ 8.614769] random: mountall: uninitialized urandom read (12 bytes read, 64 bits of entropy available)

[ 10.892396] random: lsb_release: uninitialized urandom read (24 bytes read, 96 bits of entropy available)

What are these random bits used for during boot and why?

Also, the urandom read is "uninitialized". What does this mean?

I am using Ubuntu 14.04 (kernel 4.4.0-127).

I have created short bash script to run some program 10 times and save the output to a file. While I was setting the executable permissions I thought that it would be nice to remove the write permission, so that the script can not be changed without sudo/root access. But what I got was this:

use@ubuntu:~/some/folder$ sudo chmod -w Run_SIM.sh 
chmod: Run_SIM.sh: new permissions are r-xrwxr-x, not r-xr-xr-x

Why?

Which scripts are executed when we click on shutdown or reboot?

Using Ubuntu 14.04.5.

I have to find specific file with known sha1 sum. I know in which folder the file should be, but there are sub-folders (up to max-depth 4). I know more or less parts of filename (contains words "project" and "screenshoot"), but there are various possible file formats (.ods, .docx, .pdf ...). And of course I know what sha1 sum it has. How to find it?

I have to do this for about 15 files.

Example: I log on my laptop machine (Ubuntu 14.04) via ssh and I need to make a .log file of some command output and than transfer it to my desktop machine. The command has -o option to redirect the output to a file. I could than just copy the file with scp command.

The question is: Can redirect the output directly to my machine, without the need to first make a file on laptop and than transfering it with scp?

Both machines use Ubuntu 14.

I had some problems with subtitle files in video omxplayer. To solve it I had to convert from windows-1250 to UTF-8 encoding. My question is, how can I see for some specific file which encoding is used?

Is there any log file that saves the information of who and when logged to my computer using ssh, sshfs or some other method? Is it also possible to find some info about what was he doing (like for example the files transferred to other machine...)?

I am using Ubuntu 14.04.

I have large number of files and folders in a separate partition and I need them to be ordered by creation/modification time (in Nautilus I click on the "View items as list" button and on "Modified" colum to get this done). Few days ago I saw a sub-folder, that was not needed, in one of them and I deleted it. But that also changed the modification date of folder that contained it. Now this folder is at the top of the list.

It is not a big deal, but it got me wondering if there is a way to revert to previous modification date.

I am using Ubuntu 14.04.

I'm using Ubuntu 14.04. Today the Software Updater asked me to update to the Ubuntu 16.04 Xenial HWE Stack (v4.4. Kernel) because my kernel version will not receive any software updates (LINK). But I am using fglrx graphics driver for which I know that it is not supported by Ubuntu 16.04 kernel. So my question is, what will happen if I install Ubuntu 16.04 Xenial HWE Stack? Does it support fglrx driver or will it get automatically removed and replaced by the new open source driver for AMD graphics?

We have 10 PC with some version of Ubuntu and only remote access. While doing some upgrades to custom software I did not notice that the line endings in some scripts were Windows version (CR+LF) and not the Unix version (LF). So now when I want to launch the script it gives an error:

bash: /usr/local/bin/portsee: /usr/bin/python^M: bad interpreter: No such file or directory

Is there a way to change all line endings in a script from terminal. The thing is that I can not install any new software to this group of PC-s.

I have opened Disks program today and noticed that there is FAILING in the Assessment column for the SMART status.

What does this error mean? Is it serious problem?

I have Lenovo G50-45 laptop, disk is SEAGATE ST1000LM014-SSHD-8GB(LVD3) 1TB SSHD with 8GB NAND Flash (original disk in this latop).

Update 2017-09-24:

The disk has died yesterday. 1 year and 3 months have passed since 1st hint of problem. About 4 months ago I had few issues with it not booting, but I was able to make another clean install. Since yesterday the disk is non-responsive. As this was long expected I had backup of all important data.(!) The disk was about 2 years old, so that was quite premature death.

I have home made device that can be connected via USB port. When connected it gets ttyACM socket. So I have asked this question some time ago about how to set read/write permissions for device. Following the answer I have created /etc/udev/rules.d/50-ttyusb.rules file with this content:

KERNEL=="ttyUSB[0-9]*",MODE="0666"
KERNEL=="ttyACM[0-9]*",MODE="0666"

All works fine! But if I understand correctly, now every device connected on any ttyUSB or ttyACM socket will have read/write permissions. Right?

My question is how can I automatically set read/write permissions only for this device when connected?

Relevant lsusb output:

Bus 003 Device 005: ID ffff:0005

I have home made device that connects via USB port and I have made a c++ program for data acquisition from that device. I have modified the /etc/udev/rules.d/50-ttyusb.rules so that the device has read/write permissions when pluged. Now I would also like that when I plug-in the device my program (named SQM_ver2) would automatically run. How can I do this?

The socket assigned to device is ttyACM0. Using Ubuntu 14.04.

lsusb output for the device:

Bus 003 Device 005: ID ffff:0005

Edit:

I have modified my rules file as proposed by @steeldriver but it did not work. Note that my program uses Terminal window to output the data. I have always run it from Terminal but now it should open a Terminal by itself. Here I add also the relevant lines in /var/log/syslog file when the device is pluged-in:

Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.078011] usb 3-1.4: new full-speed USB device number 8 using ehci-pci
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.187324] usb 3-1.4: New USB device found, idVendor=ffff, idProduct=0005
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.187339] usb 3-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.187347] usb 3-1.4: Product: USBSerial
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.187353] usb 3-1.4: Manufacturer: LPCUSB
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.187359] usb 3-1.4: SerialNumber: DEADC0DE
Jun  1 22:21:04 user-Lenovo-G50-45 kernel: [267790.188792] cdc_acm 3-1.4:1.0: ttyACM0: USB ACM device
Jun  1 22:21:04 user-Lenovo-G50-45 mtp-probe: checking bus 3, device 8: "/sys/devices/pci0000:00/0000:00:12.0/usb3/3-1/3-1.4"
Jun  1 22:21:04 user-Lenovo-G50-45 mtp-probe: bus: 3, device: 8 was not an MTP device

Edit 2:

Here is how my rules file looks now:

KERNEL=="ttyUSB[0-9]*",MODE="0666"
KERNEL=="ttyACM[0-9]*",MODE="0666",RUN+="/usr/bin/gnome-terminal"

Is there an error? Instead of my program SQM_ver2 I have tried only to open Terminal, but it does not work. The permissions are set correctly, so the 50-ttyusb.rules file works at least for that part. Also, looking at my 50-ttyusb.rules file I think that now all devices that I connect and they get assigned ttyUSB or ttyACM socket will have read/write permissions (and the program SQM_ver2 would start). I should probably ask another question on how to set permissions for only this device (probably it should compare idVendor and idProduct?).

I am planing to buy RaspberryPi 3 and have it connected to my TV. I also have a lot of movies on Windows partition in my dual boot Ubuntu 14.04 & Win 8 machine (Win 8 isn't used, but is there). I would like to share the movies folder to RaspberryPi over my WiFi, so that I can watch movies on TV without loading the movie file to RaspberryPi.

Can this be done and how?

Is there a way to check in Terminal if certain process (known PID) is doing something or is non-responsive and has "hang"? Using Ubuntu 14.04 and processes in question are TestDisk and GParted.

I have a home-made device and I wrote a program for data acquisition from it. But each time I plug-in the device I have to change the permissions for /dev/ttyACM0, so that the port can be used for data transfer. How can I make this device to have read/write permissions by default. The lsusb output for this device is:

Bus 003 Device 005: ID ffff:0005

I have a homemade device for measuring night sky brightness (astronomy). I am now writing the program in c for data acquisition. I noticed that on my laptop, the device (when connected) gets ttyACM0. However, on the lab desktop (approx. 6 years old), the device is connected as ttyUSB0. So, I am interested in knowing what is the difference between ttyACM and ttyUSB?

I noticed an interesting fact today. I have a link on my Desktop pointing to windows partition (dual boot Ubuntu 14.04 & Win8.1). Because this partition is not automatically mounted the link is marked broken at restart. When I mount the partition and than double click on it it gives me an error that is broken too. But if I use ls command in Terminal on the link I can see all the content. Why is the behaviour different?

Of course if ls is used on the link before the partition is mounted, the content isn't shown.

I have created a link to directory on windows partition on Desktop in Ubuntu 14.04. Because this partition will not be automatically mounted at startup the link is marked broken each time I power on computer. So I would like that when I click on a link the command ln -s -f "path1" "path2" would be executed before the link is "opened". How can this be done?

Other option would be to make a script with icon on Desktop. When double-clicked the script would check if the partition is mounted and mount it if it is not mounted and then open the Directory I want. But I have no idea how to make this? Any sugestion?

I have created a link to some directory on a partition that will not be automaticaly mounted at start-up. Of course, when I restart the computer Ubuntu marks this link as "Broken". Is there a way to tell Ubuntu 14.04 not to check this link's path until I click on the link.

Edit: Is there a way to make Ubuntu recheck the link with some command?