DEV Community: nitiwit

making nano usable

nitiwit — Wed, 31 Jul 2024 09:40:24 +0000

nano has always been my favorite. it's not too fancy to be annoying and huge, so you can comfortably run it on servers. it's not too low-level so there's not a very steep learning curve (comparing to vi/m).
it's often pre-installed on servers too so it doesn't need installation, just write nano into the command line and there you go.

However, it's still kind of hard to work with, and get around, since it's a cli program nonetheless. some of the troubles I find myself struggling with when working with nano are (could be terminal related, or nano related):

word-wrap: I paste a long line and I see 4 characters and it takes me several seconds to have an idea about what's happened
no line numbers: a disadvantage for obvious reasons
weird shortcuts: ctrl+k cuts a line, ctrl+u pastes it, alt+delete removes the line. not very common shortcuts, for me at least.
does not ask for password on save: you need to remember and sudo nano the file when opening it. if you only nano, it won't ask you for a password before writing. it simply prompts that it's a protected file and you can't save your edits. in these cases, I just copy what I've written, paste it elsewhere, sudo nano, paste and then save. pretty annoying.

On the other hand, as mentioned before, it's very handy, versatile and fun to work with as well. so it's worth to take the extra mile and modify it based on my daily use.

two of the most useful "fixes" that I use are:

/ and enter a number: go to line
easy to use text replace (ctrl+h in vscode/etc.): ctrl+/ and enter a text to replace. enter the replacement text, and nano shows you the occurrences and confirm whichever you like to replace.
esc+shift+4 toggles soft-wrapping (google if you don't what it is. nano supports two types of wrapping.) 3.1. toggle hard-wrap with esc+l
alt+shit+3 to toggle line numbers

you can also start nano with various options to have features on or off. for example nano -Y enables syntax highlighting or nano -T sets the tab size. read more here or just man nano to check them out.

finally you can write you own ~/.nanorc and write you desired customizations there. options like set linenumbers and set autoindent are available. check out this article for more

reminds one of vi's command-mode, huh...

[linux] list processes using a file

nitiwit — Wed, 31 Jul 2024 07:59:14 +0000

processes use files and directories. you might need to know which process is using a file because it's locked the file/dir and you can't modify it, so you'll have to kill the process and edit your file. at least this was my case.

lsof +D <path>
e.g.

$ sudo lsof +D /var/log
COMMAND      PID   USER   FD   TYPE DEVICE SIZE/OFF    NODE NAME
systemd-j    539   root  mem    REG  253,0  8388608 3672301 /var/log/journal/ed214fcf933346b68d6hh6f76a18d552/user-1000.journal
systemd-j    539   root  mem    REG  253,0 58720256 3670236 /var/log/journal/ed214fcf933346b68d6hh6f76a18d552/system.journal
systemd-j    539   root  mem    REG  253,0  8388608 3670937 /var/log/journal/ed214fcf933346b68d6hh6f76a18d552/user-1000@4f8a576fe5f642e1a7f84f8f18d31870-0000000000000d26-00061de5aff72efd.journal
systemd-j    539   root   32u   REG  253,0 58720256 3670236 /var/log/journal/ed214fcf933346b68d6hh6f76a18d552/system.journal
systemd-j    539   root   38u   REG  253,0  8388608 3672301 /var/log/journal/ed214fcf933346b68d6hh6f76a18d552/user-1000.journal
vmtoolsd     818   root    3w   REG  253,0     1969 3670068 /var/log/vmware-vmsvc-root.log
rsyslogd     868 syslog    7w   REG  253,0 15700152 3671420 /var/log/syslog
rsyslogd     868 syslog    8w   REG  253,0  3626629 3671459 /var/log/kern.log
rsyslogd     868 syslog    9w   REG  253,0   253306 3671524 /var/log/auth.log
unattende    944   root    3w   REG  253,0        0 3692387 /var/log/unattended-upgrades/unattended-upgrades-shutdown.log

you can see the file name, process command and PID, and the user that has started the process. from here you can use top (or alternatives, htop etc.) to move on and inspect what's going on.

[linux] list files that contain a word

nitiwit — Tue, 30 Jul 2024 10:56:01 +0000

TL;DR use grep -rG <word>

searches for all files recursively in the current directory for files that include <word> inside them

example:

$ echo "Use Markdown to write and format posts." > tmp.txt
$ cat tmp.txt 
Use Markdown to write and format posts.

$ grep -rH "Markdown"
tmp.txt:Use Markdown to write and format posts.

this is naturally case-sensitive. to ignore cases, add the -i option:

$ grep -riH "markdown"
tmp.txt:Use Markdown to write and format posts.

⚠ Beware

when using this command is large directories (with numerous files and sub-directories), beware of getting text-walled. you might see too many results.

therefore it's recommended to limit your search queries to smaller range of directories/words.

[firefox] show tabs in full-screen mode

nitiwit — Tue, 30 Jul 2024 07:57:35 +0000

I often use my apps on full-screen mode, since there are many distraction that I don't "often" use or need to click on (including taskbar, time, search-bar, icons, etc.)

However in Firefox I usually have several (if not more) tabs open, and I find myself needing to transit among them too. right now I have 8 + 6 pinned tab :) )
the default behavior is a smooth animation where you move the cursor to the top of the screen and the tabs(-bar?) collapses down. this is rather slow and requires an extra gesture or two for me, making it annoying to get around

To always show the tabs in full-screen mode, open about:config in Firefox, search for browser.fullscreen.autohide, and set it to false. there, now you can press F11 to enter full-screen mode while having your tabs visible.

credits to Happy112 from Mozilla forums | link

[python] defaultdict

nitiwit — Sun, 21 Jul 2024 07:05:57 +0000

normal dict raises Keyerror after querying keys that don't exist

>>> from collections import defaultdict
>>> my_dict = {"one": 1, "two": 2}
>>> my_dict["three"]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
KeyError: 'three'

but by using a lamda in a deafultdict we can set default values for undefined keys

# create a default dict, from a dict
>>> my_def_dict = defaultdict(lambda: -1, my_dict)
>>> my_def_dict["zero"]
-1

# create an empty default dict
>>> empty_def_dict = defaultdict(lambda: true)
# add key-value pairs here

[python] count words in a text

nitiwit — Sun, 21 Jul 2024 06:59:47 +0000

I recently discovered a one-liner to count the words from a text in python:

text = "Tags help people find your post - think of them as the topics or categories that best describe your post."

from collections import Counter

words = Counter(text)[" "] #19

to put it more accurately, this counts the number of spaces (" ") in a text.

moreover, Counter is a python mapping that creates a dict in which keys are every unique letter from a text, and the corresponding values are the number of occurrences of that letter.

a mapping is an iterable container with a fixed length. this means three things (accordingly):

you can loop through its items
you can check existence of an item using in keyword (e.g., "x" in words)
len(words) returns an integer

in other words, it comes with these dunder methods (again, accordingly):

__getitem__(): can access item using dct["key"] notation
__iter__(): return an iterator object to be used in a for loop
__len__(): defines the behavior of len()