hasanghaforian's questions

I use Ubuntu 20.04. When I run cpp -vin terminal the output is like this:

...
...
Thread model: posix
gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 
COLLECT_GCC_OPTIONS='-E' '-v' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/9/cc1 -E -quiet -v -imultiarch x86_64-linux-gnu - -mtune=generic -march=x86-64 -fasynchronous-unwind-tables -fstack-protector-strong -Wformat -Wformat-security -fstack-clash-protection -fcf-protection
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/9/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-linux-gnu/9/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.

The problem is after the End of search list, the command does not end until I press CTRL + C.

I want to know what causes this problem and how can I fix it?

I want to do a cleanup. After somethings I did:

$ uname -a
Linux <OS_name> 5.8.0-49-generic #55~20.04.1-Ubuntu SMP Fri Mar 26 01:01:07 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

And then:

$ dpkg --list | egrep -i --color 'linux-image|linux-headers|linux-modules' | awk '{ print $2 }'
linux-headers-5.8.0-49-generic
linux-headers-generic-hwe-20.04
linux-image-5.8.0-49-generic
linux-image-generic-hwe-20.04
linux-modules-5.8.0-49-generic
linux-modules-extra-5.8.0-49-generic

Now I want to know "Is keeping linux-headers-generic-hwe-20.04 and linux-image-generic-hwe-20.04 necessary? I want to do apt purge for cleaning.

Previously I installed Ubuntu 16.04 and used an external hard disk, which its partition format was NTFS, as its /home. Recently I tried to upgrade to Ubuntu 20.04 by installing a new one and removing old one. Although I wanted to keep data that are stored in /home. So during the installation I selected Something else option and did delete/format /root, boot and ... . But wrongly I select use as ext4 from drop down list when I wanted to set mount point of external hard disk as /home. After completing the installation the I saw the problem: grub rescue error. At first I tried to fix that by reinstalling grub; bit the problem was not that. Because when I was unplugging the external hard disk the OS could boot (although in a long time) and when it was plugged, I saw grub rescue error.

Now I installed Ubuntu 20.04 for using temporarily and backing up data from external hard disk by connecting it to a machine with MS Windows OS and using ext2explorer. But want to reinstall Ubuntu and use external hard disk as its /home again. I think it may be possible to be done by selecting Something else and deleting/formatting hard disk and setting it as /home. But it takes a long time for restring backed up data from MS Windows to the external hard disk after installing Ubuntu. Is it possible to install Ubuntu and set external hard as /home without doing those?

I use Ubuntu 16.04 and do not look for something like Graph_Easy which parses input, instead I look for some offline, free, WYSIWYG software that does tasks like what asciiflow does. For example these features are necessary:

• drawing multiple type of shapes (lines, arrows, rectangles) by dragging
• changing zoom level of page for drawing more longer/wider graphs
• typing text

asciiflow provides a mean for resizing shapes, which is not necessary for me. Also it is better to be able to draw other shapes like circle. An open source software is appropriated.

I use Ubuntu 16.04 and have installed VirtualBox-5.1.38_Ubuntu r122592. Previously I installed VBoxGuestAdditions.iso by this command:

$ sudo apt-get install virtualbox-guest-additions-iso

Now I downloaded VBoxGuestAdditions_5.2.18.iso from VirtualBox Repository and copied that in /usr/share/virtualbox. I thought that installs newer downloaded archive, but it seems it is not correct, because when I run $ sudo apt-get install virtualbox-guest-additions-iso get this result:

Reading package lists... Done
[...]
virtualbox-guest-additions-iso is already the newest version (5.1.38-0ubuntu1.16.04.1).

How I can install that manually?

I use Ubuntu 16.04 and connect my machine alongside other machines by using a switch to a modem to use Internet. Today I encountered a problem:

Other machines can connect to the Internet; but I cannot access the web (Server Not Found error on browser and ping: unknown host google.com as result of $ ping google.com in terminal), except after doing disconnecting/re-connecting network cable. But this way only works for a short time, a few seconds up to 2 minutes. Meanwhile, my Android device can connect to the web continuously without any problem through WiFi.

I tried connecting my machine directly to the modem and even changed the network (Ethernet) cable. But result was the same.

What causes this problem and how I can solve it?

Edit

I can open 192.168.1.1 from my machine but cannot login; although it is possible to do that from my other machines.

Edit1

I checked my connection and /var/log/syslog. It seems that my machine automatically changes used connection from Internet (which is used to access web) to virbr0 which causes problem:

When I can access web:

When problem occurs:

I think virbr0 must be created and used by VirtualBox. I use VirtualBox 5.1.38. Also sometimes I can access the web without any problem from my guest OS, during time that I cannot do that from host! But I created guests along time ago, for example 2 or 3 monthes ago, and this problem occurred only this week.

Edit2

result of nslookup askubuntu.com when I can access the web:

$ nslookup askubuntu.com
Server:     127.0.1.1
Address:    127.0.1.1#53

Non-authoritative answer:
Name:   askubuntu.com
Address: 151.101.1.69
Name:   askubuntu.com
Address: 151.101.65.69
Name:   askubuntu.com
Address: 151.101.129.69
Name:   askubuntu.com
Address: 151.101.193.69

Edit3

I did these; but problem remains:

• using another modem
• replacing network cable with another

Also I tethered my machine to an Android device and could access the web without any problem.

Edit4

I could connect to Internet in guest session without any problem, so it seems that problem only occurs on my current account and I'm sure NIC does not cause this problem.

I use Ubuntu 16.04 and installed NVIDIA driver. Today after doing automatically proposed update, I cannot login to Ubuntu. I tried these ways:

• deleting NVIDIA or deleting /home/*/.Xauthority files (Can't login to Ubuntu 16.04 after upgrade)
• Uninstalling ubuntu-desktop and installing xubuntu-desktop(https://superuser.com/q/1106510)

But no one could help me. I think problem is caused by disabling some things during installing NVIDIA. How I can solve my problem?

I use Ubuntu 16.04 on a machine with Intel® Core™ i7-5820K CPU @ 3.30GHz × 12 and 8 GiB RAM. Recently I installed Genymotion 2.12.1 and created a Custom Phone - 8.0 - API 26 - 768x1280 virtual device with 4 processors and 2048 MBof RAM. But when I start that device, it freeze at boot. What cause this problem and how I can solve that?

I copied huge number of (Android SDK) files from a shared directory to my system. Now all files which their MIME types are application/x-shellscript or application/x-executable, seems that are not executable. For example when I try to run mksdcard I get this error:

$ ./mksdcard
bash: ./mksdcard: Permission denied

How I can find only files with those MIME types? And then how I can change those permissions?

Notes:

1- When I tried find <path> -type f -executable with as root user it shows all files (even .PNG files) and when I tried that with standard user, it shows nothing. I do not know how to filter files with attention to their MIME type.

2- Share directory (source) currently is not accessible.

I use Ubuntu 14.04 and know I can send a notification to the screen by executing this command in a shell (.sh) script:

notify-send "Task complete."

But it does not seem when another application (for example a game) is in fullscreen mode. How I can solve this problem?

I try to open Google Chrome by running this command, but the result is strange:

$ google-chrome
Please launch slimjet via the wrapper script: flashpeak-slimjet

Why above command does not open Google Chrome and also what is the meaning of above result?

Edit:

Here is the result of which command:

$ which google-chrome
/usr/bin/google-chrome

Also, /opt/google/chrome/google-chrome and google-chrome-stable both open Google Chrome. But again, my questions are why google-chrome does not?and why flashpeak-slimjet is proposed?

I wanted to install OpenJDK-8 on Ubuntu 14.04. So as described here I tried to find the correct name of package (which is openjdk-8-jdk) and run these commands:

sudo apt-get update
sudo apt-get install openjdk-8-jdk

But I got:

E: Unable to locate package openjdk-8-jdk

So I went to Ubuntu Packages Search and Ubuntu Updates and searched for package. But I could not find any thing about trusty (14.04LTS) or trusty-updates. So I was sure there is no install able package to be installed on Ubuntu 14.04.

Of course after sometimes I suddenly found that package belongs to openjdk-r/ppa repository and added that:

sudo add-apt-repository ppa:openjdk-r/ppa

But I want to know how I can find appropriate repository (in above example the openjdk-r/ppa) before consuming times and waiting for chance?

I use Ubuntu 14.04. When I tried to sign in to gmail I get This message in w3m:

The number of redirections has exceeded a limit. This may have happened due to the server side miss-configuration. Otherwise, try increasing the limit, the value of `w3m-follow-redirection'.

And then an email received to me which said:

Your Google Account ... was just used to sign in.

Is it possible to sign in to gmail and yahoo mail by emacs-w3m?

I use Ubuntu 14.0.4 and some times, use w3m and XTerm as browser. I saw EastAsianWidth.txt which seems contains Persian letters. So I expect w3m will show Persian words. Also this is Charset Settings of w3m:

As you can see, value of display charset is Unicode (UTF-8). But I can not see Persian words. How I can solve this problem?

Before, in Windows, I used notepad++ and it has an option TextFX->Edit->Reindent C++ code for reformatting code. Now I use Ubuntu 14.0.4 so I use notepadqq as alternative for notepad++. How I can achieve a similar result in notepadqq?

We can use this command to label each image by its name:

montage -label '%t' -size 512x512 "./img/*.*[120x90]" -geometry +5+5 photo.png

I want to label images by a list of strings, which is written in a text file. Docs say:

If the first character of string is @, the image label is read from a file titled by the remaining characters in the string. Labels in a file are literal, no embedded formatting characters are recognized.

But I could not use a file to provide label. I use a command like this:

montage -label @un.txt -size 512x512 "./img/*.*[120x90]" -geometry +5+5 photo.png 

Above, un.txt is the name of text file in ./img/ path. This is a sample result:

In the result, all images are labeled with the string @un.txt instead of content of un.txt. Also I get this error in terminal:

montage.im6: improper image header `./img/un.txt' @
error/txt.c/ReadTXTImage/429

If I copy un.txt to the current (.) directory and run above command again, I will get this image (there is no label) and below error:

montage.im6: improper image header `./img/un.txt' @
error/txt.c/ReadTXTImage/429. 

montage.im6: not authorized `@un.txt' @
error/property.c/InterpretImageProperties/2959.

In Microsoft Windows, when you are open File Explorer at a specific path, you can press Ctrl+N to open another file explorer in the same path. But in Ubuntu when I try Ctrl+N it opens Home Folder. How I can duplicate the same file browser window? (I use Ubuntu 14.04)

I use ClamAV on Ubuntu 14.04, does it scan compressed files? I looked in its documentation but couldn't find anything. Also does it detect viruses that affect Microsoft Windows?

I have no experience in about Apache and want to set up Apache Virtual Hosts on Ubuntu 14.04 LTS for a local site on my local machine. I followed this page. But when I try to test http://example.com I got this result in browser:

 Example Domain

 This domain is established to be used for illustrative examples in
 documents. You may use this domain in examples without prior
 coordination or asking for permission.

 More information...

And I expected to get Success! The example.com virtual host is working! as result (as described in followed tutorial).

In that tutorial, I did not understand:

 For the domains that I used in this guide, assuming that my VPS IP
 address is 111.111.111.111, I could add the following lines to the
 bottom of my hosts file

So I used 111.111.111.111 in /etc/hosts and I guess problem is in about that, but I searched in google and did not find any thing about how to get my VPS IP address to use that. Now how I can get that address or I make mistake and I have to set an address and then use it? In second case how can I do that?

Recently I installed Android Studio. Now I want to add android-studio/bin/ persistently to PATH environmental variable as Session-wide environment variables and not as System-wide environment variables. To do that I tried to edit ~/.profile as described here. So I have these at the end of ~/.profile:

if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH:/usr/local/Android/android-studio/bin"
fi

Then I re-login to initialize the variable. But when I run studio.sh in terminal, I get this:

studio.sh: command not found

Here are results of $PATH and echo $PATH:

$ $PATH 
bash: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
No such file or directory 
$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

Also I'm sure that ~/.bash_profile and ~/.bash_login do not exist. Now what cause the problem and how I can solve that?

Edit:

I change end of ~/.profile to this, but it does not work:

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
    PATH="$PATH:/usr/local/Android/android-studio/bin"
fi