General Archives • Linux Tips

Let’s Play With Touch And Time

Today’s article is just a fun article where we get the chance to play with touch and time. This article won’t necessarily be something you rely on daily, but it should at least be informative. That and there’s surely a subset of users who use these commands. There’s bound to be! Otherwise, why would they make touch flags for adjusting the time?!?

We’ve used the ‘touch’ command before.

Some Useful Ways To Use The Touch Command In Linux

I’m pretty sure we’ve also used the touch command in at least another article. There are a lot of search results for the word and it’s not important enough to go looking. The key point is that touch is a command you use in the terminal and it describes itself as:

touch – change file timestamps

See, we (and perhaps most other sites) have used the touch command to *make* files, but it’s useful (and intended for) changing file timestamps. Like oh so many commands, there are all sorts of ways to use it and so many folks do things in their own way. The great thing about Linux is that we have so many choices.

This is why I figure I’ll cover touch and time in this article. It’s just a few commands that we’ll be using, so it’s not all that advanced. A beginner probably won’t need to know this sort of information, but it’s information worth sharing.

Playing With Touch And Time:

As we use touch in the terminal, you’re going to need to have an open terminal to play with touch and time. If you don’t know how to open a terminal, press CTRL + ALT + T and your default terminal should open.

With your terminal now open, let’s start by creating a file:

touch foo

touch foo

That command will create a file with a created timestamp from the time you ran the command. If you want, you can change the access time, that is the time stored with the file that says when it was last accessed. Run the following command with the -a flag:

touch -a foo

1	touch -a foo

That’ll change the ‘foo file’s access time to the time when you ran the command. All well and good? Alright… Let’s remove that file with:

rm foo

rm foo

Now, we’re going to create the foo file again, but we’re going to give it a specific timestamp. The format you want is:

touch -t <year><month><day><24 hour><minutes>.<seconds>

1	touch -t <year><month><day><24 hour><minutes>.<seconds>

Or, something like this:

touch -t 202303010001.01 foo

1	touch -t 202303010001.01 foo

That will give the file a timestamp from March 3rd at one minute and one second past midnight. Note the period denoting seconds as that’s the only modifier you need for this command.

NOTE: If you use a different time format, that command might be different for you. I don’t think it is, but I’m not set up to test that. If it does matter, please let us know in a comment, thanks!

Finally, let’s say you have a file named ‘bar’ and you want ‘foo’ to have the same timestamp that bar has. You can do that with the touch command. It’s relatively easy to do with the -r flag:

touch -r bar foo

1	touch -r bar foo

That command will give foo the same timestamp that bar has, should you be inclined to do so. It’s pretty easy to use the touch command to change a timestamp on files, which is why you might not want to rely too much on timestamps. They can be useful, but they are not immutable.

You can run the command above to delete the foo file when you’re done playing around with the touch command:

rm foo

rm foo

Closure:

There you go, another article. This time, we’ve had an article about using touch and time, which is kinda why the touch command exists in the first place. It’s far more useful than just creating files. Be sure to run man touch (no inappropriate jokes) in the terminal to learn more about the touch command. There are other touch commands that you may find yourself interested in, I’ve just covered a few of them.

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

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How To: Show File Sizes When Listing Files In A Directory

Today we’re going to have an easy article that shows you how to show file sizes when listing files in a directory. It’s a simple set of commands and easy enough for a newbie to learn. Though the title is unwieldy, read on to learn how to show file sizes when listing files in a directory…

We’ll be using the ‘ls’ command for this exercise. Like normal, I’ll go ahead and suggest you read this page about why you shouldn’t parse the output from the ‘ls’ command. There are better ways and that link will explain it, and what you should consider, far better than I can.

Anyhow, the ‘ls’ command defines itself as:

ls – list directory contents

Of course, regular readers will recognize the ls command as we’ve used it numerous times before. Even though you shouldn’t parse the output from the command doesn’t mean it’s not still useful for a variety of other tasks.

Today, we’ll be exploring one of those tasks. We’re going to show you how to show file sizes when listing files in a directory – specifically with the ls command. Don’t worry, you won’t need to install anything. If you’re using any desktop Linux distro, the ls command is certainly available to you by default.

For the record, you should probably view the ls man page (run man ls in the terminal) to learn more about the command. It’s still a useful command – and I do sometimes parse the output from the command, but only when nobody is looking and when the output isn’t all that vital. I use grep with the ls command almost every day! Shh!!!

Show File Sizes When Listing Files In A Directory:

(That’s an unwieldy title!)

Anyhow, it’s the ls command. That’s a terminal-based command. So, of course, you’re going to need an open terminal (like so many of these articles). Press CTRL + ALT + T and your default terminal should open. Tada!

With your terminal now open, we can just use your home folder. To run the basic ls command, it’s just that:

ls

Now, to show file sizes when listing files in a directory, you’d start with the -s flag:

ls -s

ls -s

You may find the output from that command is relatively useless without doing a bit of math to go along with it. Fortunately, you can tell the command to show the file size in a ‘human-readable format’. To do that, you’d run this command with the -h flag:

ls -sh

ls -sh

Now, if you wanted to show all the files, including the hidden files in that directory, you’d just add the -a flag. The command would look like this:

ls -ash

ls -ash

And if I was a Linux newbie, that’s the command I’d commit to memory. It doesn’t make a mess. The output is still plenty clear. It’s easy to understand. It’s easy to remember and turn into a habit. This way, when you ran the ls command, you just default to using -ash flags.

If you don’t want columns (and some do not), and you want more information such as file permissions or ownership values, you can just add an -lflag to the above. That’d look like:

ls -lash

ls -lash

So, it’s up to you…

You can remember ‘ash’ or you can remember ‘lash’. You can also not remember either and ignore the flags completely, but I find developing a habit is a good way to remember things. It’s your device, you do what you want!

Closure:

There you have it! You have another article. This one was simple enough and I hope you found it useful. If you’re new and running the ls command is new to you, it’s worth learning some additional flags and gathering more information at a glance. That’s why there’s this relatively simple article that shows you how to show file sizes when listing files in a directory.

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

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How To: Find A Site’s Nameservers

Today’s article will be a fun and easy one if you already understand nameservers, as I will be explaining how to find a site’s nameservers. If you don’t understand nameservers, it may be a bit more difficult. But, I’ll do my best to make it approachable. So, to learn how to find a site’s nameservers read on!

Okay, so what are nameservers?

Hmm… Let’s try to explain it in the most simple way possible…

DNS is like a phone book. You look in the book to see which number (IP address) to connect to. However, just like in the real world (though less common with cell phones) a given telephone number may belong to multiple people.

Nameservers help to organize those DNS records. Using the nameservers is sort of like calling a phone exchange and then entering a party’s extension number to go directly to that person.

Does that make sense? No? Well, that’s the best you’re getting. I suck at analogies unless they’re automotive-related and I can’t come up with one that makes sense. I’m pretty sure the above was how it was first explained to me, or something like that. Ah well…

It should be pointed out that I used ‘dig’ in the previous article. We’ll be using that again. This time, we’ll be using dig to find a site’s nameservers instead of the site’s IP address. We might as well learn about it now, while the dig command is fresh in our memories!

Find A Site’s Nameservers:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

With your terminal now open, the syntax for finding a site’s nameservers is as follows:

dig NS <domain_name>

1	dig NS <domain_name>

Or, if you prefer a shorter output, you have:

dig NS +short <domain_name>

1	dig NS +short <domain_name>

Like the previously used dig command, you can actually put the flags at the end (if that’s something you feel like doing). It works just fine like:

dig <domain_name> NS +short

1	dig <domain_name> NS +short

If we use this site as an example, the outcome of the latter command should look something like this:

using dig to find a site's nameservers — And there you see them, this site’s nameservers as shown by dig. Pretty easy, huh?

As you can see, nameservers look just like domain names. You’ll also note that those (shouldn’t) don’t change, unlike the site’s IP address. As we’re using a CDN, there are a number of possible IP addresses. The nameservers will be the same no matter what part of the globe you connect from.

Of course, there’s more to the dig command. We’ve just touched on a couple of uses. Check the man page with man dig to find out what other options are available.

Closure:

Well, there you have another article. Once again, we’ve used dig in this article. I figured we might as well have another dig article while I was thinking about it, and this time we used dig to find a site’s nameservers. Hopefully, this will be useful for you at some point in your Linux journey. As I deal with a bunch of websites, it’s important for me to know my nameservers and to know when they’ve propagated (something for another article).

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How To: Search For Files By Name

Today’s article isn’t going to be all that complicated, as we’re just going to cover one way to search for files by name. It is a pretty useful skill to have, and a skill that one should probably learn early on. If you want to learn how to search for files by name, read on!

So many of us will parse the output of the ‘ls’ command, but you really shouldn’t parse the output from ‘ls’. Sure, it’s nice and easy to use something like ls -la | grep <filename>, but that’s a bad idea for reasons better explained by clicking the above link.

One of the options you can use instead of ‘ls’ would be the ‘find’ command. We’ve used it a few times before, but this time we’ll be using it to search for files by name. It’s relatively easy and I’m sure you can figure it out. The find command’s man page defines itself as:

search for files in a directory hierarchy

Which is a good description, because that’s what it does. Which is also good, because that’s what we want it to do! So, let’s get this article started rather than wasting time in the intro…

Search For Files By Name:

With your terminal now open, the command you’re looking for would look a little like this example:

find <dir> -type f -name <file_name>

1	find <dir> -type f -name <file_name>

As you can see, you must declare a directory and a file name. If you want some level of leeway, you use ‘-iname‘ which indicates that it isn’t case-sensitive. As a matter of habit, I use ‘-iname‘ instead of ‘-name‘. This works for me and we’ll use ‘-iname‘ from here on out.

Let me give you an example…

Say you wanted to find the ‘firefox.desktop’ file and ensure it’s there. You could use this command:

find /usr/share/applications/ -type f -iname firefox.desktop

1	find /usr/share/applications/ -type f -iname firefox.desktop

Of course, if you aren’t sure it’s a desktop file, you can use:

find /usr/share/applications/ -type f -iname firefox*

1	find /usr/share/applications/ -type f -iname firefox*

The asterisk means anything, so you’ll get results for firefox.desktop as well as anything else.

If for some reason, you wanted to search your entire system for anything containing firefox, it’d look like this:

find / -type f -iname firefox*

1	find / -type f -iname firefox*

That’ll likely throw a whole lot of errors, as you don’t have permission to look in those areas, so you just add sudo to the command:

sudo find / -type f -iname firefox*

1	sudo find / -type f -iname firefox*

Which should show you every instance of a file starting with firefox on the entire computer. The ‘find’ command can seem pretty difficult to tackle for a new person, but if you take it in small bites you’ll start to learn that it’s not all that complicated. Be sure to check man find for more details.

Closure:

There you go… It’s yet another article. This time, we’ve covered how to search for files by name, a task that you may do with some frequency. If you know what you’re doing, it’s possibly faster than rooting around in a GUI hoping you find the right directory.

You don’t even need to know the entire file name to at least narrow it down a great deal. So, it’s a great tool to add to your toolbox and is more reliable than parsing the output of the ‘ls’ command.

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Meta: The State Of Linux Tips #15

Today’s article is just a meta article, one where we cover the state of Linux Tips (this site). It’s just a chance to sit down and share what’s going on with the site, a chance to not write something technical. So, for another meta article, read on!

This will be mostly about the month of February. See, I didn’t write any meta article(s) in February. It just didn’t cross my mind and it was a shorter month than the months surrounding it. So, I suppose, this will be about February.

I try to write these meta articles once a month, but they’re never really formally scheduled. They just get written when I remember to write one and when I have the urge to do so. I should probably pick a specific day of the month and write them on that day, but where’s the fun in that?

So, about February…

The State of Linux Tips:

February only has 28 days. Because of this, Linux Tips did not have more traffic than the month before. If February had been 29 days, I’d have had slightly more traffic than was had in the month of January – which has 31 days. (Traffic for this month appears to be breaking all sorts of records.)

Like always, the vast majority of my traffic came from Google. However, that number has jumped a great deal. I had about 6200 visitors from Google in the month of February. The site’s getting more and more popular, or so it seems.

In February, I had 12,655 unique visitors. In January, that number was 12,885 unique visitors. So, if February had been just a few hours longer it’d have had more unique visitors than the month prior. I’m going to put that one in the ‘win’ column!

Google’s definitely taken me out of the doghouse, but the ad clicks are worth less than they used to be before they put me in the dog house. Amusingly, this coincides with my CDN deciding the amount I had been paying is an ‘introductory rate’ and will be doubling the cost. I bought a bunch of credits, hoping that they’ll still be worth the same as they are now.

That’s not actually a complaint. They provide a great service and the cost isn’t that much. I know, I ask for donations and I have ads, but the reality is that the site will remain online for the foreseeable future.

The expenses aren’t so great that I can’t handle them. If they ever do become more than I’m willing to pay, I’ll be sure to let folks know and let folks decide how much they value the site. But, really, don’t worry about it all that much. We’re good!

Some Linux-Tips Numbers:

Hmm… How about the three articles AWstats tells me had the greatest traffic numbers?

Find Out Which Display-Manager You’re Using
Screenfetch vs. Neofetch, You Decide!
How To: Restart TeamViewer From The Terminal

That’s a bit interesting, as here’s what Google says were my top 3 pages:

It agrees with the #1 slot.
The #2 slot (according to Google) is the TeamViewer article.
How To: Stop, Pause, and Resume Processes Running in Your Term

But, Google’s not very good with counting traffic. Google seems to me to not count anyone that doesn’t allow the Google cookie. So, if you’re blocking ads appropriately, you are also probably blocking the cookies from the blocked sites. That means Google isn’t very good at counting traffic.

For example…

According to Google Analytics, my monthly visitors for February was a total of ~4800 people. (That’s pretty amazing, as the previous month was like ~4200.) It does say that I was in the search engine results some 365k times. But…

In reality, I had almost 13k unique visitors and a total of ~17.5k total visits.

So, for all the complaints about Google tracking people, they’re not very good at it. Also, they really suck at figuring out what kind of ads I’d like. I’m not allowed to click on them, but I do see them. They’re seldom for anything I’m interested in.

Still, you should whitelist this site and Google wants you to only click on ads that are of legitimate interest to you. Don’t just click ads to be nice. I appreciate that, but it’ll just screw me over in the end. As it is, Google loves to call clicks invalid for reasons I do not know.

Closure:

There’s still a lot going on here. There’s still more articles to write. I could use a bit of a break now and again, so speak up if you’re wanting to write an article for the site. (And you’re not looking to use my site to boost the ratings of unrelated sites, of course…)

We’ll see when the next meta article comes along, but it probably won’t be in the month of March. It could be, I dunno… Oh, and I chewed through about 20 GB of bandwidth with 5 of those GBs being gratis.

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