Author: ersi

/tmp is a system section that is rather active. Temporary downloads get directed there. Package manager (system updater) works through it. Building packages, if not specifically directed elsewhere, also works through the same section.

Why mount /tmp to RAM?

If your hardware uses SSD instead of HDD, you may want to reduce disk activity as SSD is sensitive to it and supposedly gets worn out easily. Reduced number of disk writes can be achieved by mounting /tmp to RAM. There are instructions on the net how to do it.

However, systems built around systemd may already direct /tmp to RAM out of the box. I don’t know if all systemd distros do this, but Manjaro does. More specifically, systemd treats /tmp as tmpfs, which means /tmp is directed both to RAM and swap.

Why not mount /tmp to RAM?

Allowing /tmp to operate in RAM is desirable, if the system disk is an SSD instead of HDD. But when you use HDD, which is more likely, and you compile source into packages every once in a while with relatively limited RAM, then it’s more desirable to have /tmp operate on the disk rather than in RAM. When you compile code into packages and RAM runs out of space, you will get an error.

Find out if /tmp is treated as tmpfs

In terminal, type:

df -h

The result may be like this:

/dev/sda6           15G    6,3G  8,3G  44% / dev                3,9G       0  3,9G   0% /dev run                3,9G    9,0M  3,9G   1% /run tmpfs              3,9G    272K  3,9G   1% /dev/shm tmpfs              3,9G       0  3,9G   0% /sys/fs/cgroup tmpfs              3,9G     20K  3,9G   1% /tmp

Find /tmp in the last column and see if it says tmpfs in front of it in the first column. If yes, and you use HDD and have limited RAM, consider changing the situation.

Pointing /tmp to HDD

In distros with systemd, the solution is:

systemctl mask tmp.mount

After this, df -h should result in something like this:

/dev/sda6           15G    6,3G  8,3G  44% / dev                3,9G       0  3,9G   0% /dev run                3,9G    9,0M  3,9G   1% /run tmpfs              3,9G    272K  3,9G   1% /dev/shm tmpfs              3,9G       0  3,9G   0% /sys/fs/cgroup

Plainly, /tmp section should vanish. May take a reboot for full completion of the change.

Non-systemd

In other distros it’s more likely that /tmp was not pointed to RAM in the first place. If it was, it should be possible to change this by editing and reloading /etc/fstab.

Here’s a follow-up to the blog post Create a bootable USB stick in Linux.

The first time I reformatted my USB stick from bootable to a normal file-storage device, I followed some other instructions, but now Webupd8.org instructions worked.

THE PROCEDURE

1. Insert the USB stick.

2. In terminal, issue:

dmesg | tail

3.There will be the description of the activities of the last active device. The device name will be between brackets as [sdd], [sdc] or [sdb]. See what you got and remember it.

4. Unmount the device. It should work by issuing in terminal:

sudo umount /dev/sdb

The sdb bit should be your own device of course. However, sometimes the command doesn’t work. I had to use the graphical file manager to unmount the device.

5. Reformat by issuing in terminal:

sudo mkdosfs -F 32 -n 'Label' -I /dev/sdb

The -F 32 can be omitted, but it ensures the most Windows-friendly format.

The ‘Label’ gives the device a name. You can have ‘MyUSB’ or such, if you like.

6. After the last command has done its thing (may take time), remove and reinsert the stick to test the result.

NTFS File System

When the aim is to format the stick as ntfs instead of msdos file system, step #5 is different:

sudo mkntfs -L Label -I /dev/sdb -F

Note the little differences from step #5 compared to msdos file system:

• Label is without quotes
• With ntfs, -F means “force” (to override an error message) rather than “format” (try mkntfs without -F and see what you’ll get)

All the other steps are the same.

After a system update, Mplayer failed to launch. It gave this error:

mplayer: error while loading shared libraries: liblirc_client.so.0: cannot open shared object file: No such file or directory

Looking around the web for solution, I found that the fault is in the dependency called lirc-utils.

Solution #1: Reinstall lirc-utils

Solution #2: Recompile Mplayer without dependency on lirc-utils

In PKGBUILD under ./configure –prefix=/usr \ add –disable-lirc

Solution #2 found here https://bugs.archlinux.org/task/18526

Note: These instructions erase the whole stick. The result will be just one bootable OS on the stick. In the next post I will tell how to get the stick back to normal, somewhat.

1. Stick the USB stick in the computer
2. In the terminal, determine the device:

   sudo ls -l /dev/disk/by-id/*usb*

   The device listed multiple times, with a number in the end and without, is the one to use. E.g. /dev/sdb

3. If you have automount enabled, unmount the device.
4. cd to the folder where the iso file is.
5. Create bootable device:

   sudo dd if=filename.iso of=/dev/sdb bs=4M; sync

   The device path is an example. However, it must be without number in the end.

Learned from here http://crunchbang.org/forums/viewtopic.php?id=23267

Xterm is a terminal emulator for Linux that I like a lot. For some reason it’s not the default emulator in any distro that I know of. This post is about how to make Xterm select-and-copy-to-clipboard with mouse.

One of the features I like in Xterm is the way copy and paste work there. Namely, it’s not emulating modern word processors in this, where you Ctrl+C (or, more often, Ctrl+Shift+C) to copy and Ctrl+V (Ctrl+Shift+V) to paste. Instead, the mouse works there in peculiar ways that may seem cumbersome at first, but make sense later, after some infotechnological enlightenment.

The move to copy

Xterm allows copying with mouse this way:

• Select a letter (Left-click+Drag)
• Release the mouse button and move the mouse where you want to end the selection
• When the mouse pointer is where you want to end the selection, Right-click

This selects everything from the first selected letter (which was really only to mark the beginning of the selection) to the right-click. In truth, this move both selects and copies, but it’s not obvious that it copies.

Multiple buffers

Terminal emulators distinguish three buffers, two of which are important – at least for my purposes. The two important buffers are Primary and Clipboard.

The described move to select text in Xterm also copies it at the same time to the primary buffer. This means it’s possible to paste it (with Ins or Shift+Ins or a keyboard shortcut specific for the program open in the emulator) in Xterm only, not paste it elsewhere in the desktop. To be able to copy from Xterm and paste elsewhere, a tweak is necessary.

The tweak to copy to the clipboard in Xterm

Note: The tweak will copy to the clipboard buffer, not only to primary. This will make the distinction of primary and clipboard buffers disappear. If you need the distinction, don’t use this tweak.

In your home folder, a text file named .Xresources or .Xdefaults probably already exists. If not, create it. Create just one of these, not both.

In the file, paste this line:

XTerm*VT100.translations: #override : select-end(PRIMARY, CLIPBOARD, CUT_BUFFER0)

Save the file. To make the function take effect immediately, issue this command in the terminal:

xrdb -merge .Xresources

If you created the file by the name .Xdefaults, use that name instead of .Xresources. All this done, the described move to select text with mouse in Xterm should do select-and-copy-to-clipboard so that it can be pasted to any other program on the desktop.

Elinks is a console-based webbrowser that allows some interaction with mouse. At first glance it’s impossible to grab text, but this works by point-click-and-drag when holding down Shift key. This post is about a specific mismatch of default settings between Manjaro Openbox desktop and Elinks web browser.

For a while I was puzzled why Shift+Left-Click+Drag doesn’t select text in Elinks in Manjaro Openbox desktop, but the answer is stated openly in the default conky script on the desktop: Left-Click+Drag is reserved for moving windows around on the desktop and this conflicts with the function in Elinks despite the distinction of Shift being pressed or not.

I decided to change the desktop default. The solution is to find, in Openbox RC (.config/openbox/rc.xml), the guilty section that causes the mouse behaviour and to remove it or comment it out. Since I removed it already months ago, I don’t even remember what the actual section was – and I am happy about this.

The result is that Shift+Left-Click+Drag will select text in Elinks again. Also, dragging windows around remains working, only not in the entire window area any more. Now you have to select precisely the upper window bar to Left-Click+Drag windows on the desktop.