An alias to show bash.rc text

[Vic]

I needed an alias to show some code to copy, paste and edit without leaving the terminal.


Thanks to this thread https://unix.stackexchange.com/question ... mmand-line I found "tail filename.txt" .


I made an alias with 'tail /root/.bashrc' and placed the code to be modified at the bottom of my bash.rc file.


The last 12 lines of bash.rc appear in the terminal and I am back to the prompt.


Hope this is useful to someone.


Vic

[Rava]

^


https://unix.stackexchange.com is indeed your friend.
I <B the many alternatives that are given in https://unix.stackexchange.com/question ... mmand-line and also this

I always use $ less "your file here" , as it is very simple, provides a built in interactive grep command, and gives you an easy to use interface that you can scroll with the arrow keys.

(highlighting by me) - these are my precise reasons for using less that often.

Since I have lots of aliases and functions, I have them in their own file:

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guest@rava:~$ /bin/ls -o --time-style=long-iso /usr/local/bin/aliasset | cut -c 19-$(expr 18 + $(tput cols))
10619 2023-10-20 11:33 /usr/local/bin/aliasset

As you can see, currently it holds 37 aliases and 15 functions:

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guest@rava:~$ grep "^alias " /usr/local/bin/aliasset|wc 
     37     168    1882
guest@rava:~$ grep "^function " /usr/local/bin/aliasset|wc 
     15     237    1703

The "^" is a special character meaning "beginning of a line" (while "$" would be the special character meaning "end of a line") More precise it means "start / end of the string" but in this case, that is also "start / end of a line"

And it is auto-loaded for guest and root via this snippet in their respective .bashrc :

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guest@rava:~$ grep aliasset .bash*
.bashrc:. /usr/local/bin/aliasset

(Since I do not check if /usr/local/bin/aliasset is available that would produce an error if its not available; but on all of my systems that's not an issue since I use aliasset longer than Porteus exists. Currently its version is "V3.6.47 (2023-10-20)")
And out of security-reasons, aliasset is readable by guest, but only writeable by root:

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guest@rava:/usr/local/bin$ ls -l aliasset 
-rw-r--r-- 1 root root 10619 2023-10-20 11:33 aliasset

Having the aliases and functions in their own external file has one more advantage: when I created a new alias or a new function and added it to an updated aliasset, I can load that into one already running terminal via a simple

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guest@rava:~$ . /usr/local/bin/aliasset

Typed that is a mere
. /u[TAB]lo[TAB]b[TAB]ali[TAB]
And when there would be some error or syntax error in the newest created /usr/local/bin/aliasset - executing . /usr/local/bin/aliasset would only give an error on that one terminal, and in the worst case scenario would only mess up that one terminal. Then I repair the coding error in /usr/local/bin/aliasset or revert it to its previous version, and all is good. The other already running terminals or virtual terminals are not affected.
────────────────────────────────────────────────────────────────────────
More on special characters and regex in general I collected in my help.regex help script:

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guest@rava:~$ help.regex 
help.regex V0.1

Character classes
.		any character except newline
\w \d \s	word, digit, whitespace
\W \D \S	not word, digit, whitespace
[abc]		any of a, b, or c
[^abc]		not a, b, or c
[a-g]		character between range from a to g

Anchors
^abc$		start / end of the string
\b \B		word, not-word boundary

Escaped characters
\. \* \\	escaped special characters
\t \n \r	tab, linefeed, carriage return
\u00A9		unicode escaped (c)

Groups & Lookaround
(abc)		capture group
\1		backreference to group #1
(?:abc)		non-capturing group
(?=abc)		positive lookahead
(?!abc)		negative lookahead

Quantifiers & Alternation
a* a+ a?	0 or more, 1 or more, 0 or 1
a{5} a{2,}	exactly five, two or more
a{1,3}  	between one & three
a+? a{2,}?	match as few as possible
ab|cd		match ab or cd

(The original help.regex makes coloured output but that cannot be displayed using [ code ] )

HTH.

[Vic]

Hi Rava.

You blow me away man.

Vic

[Rava]

You blow me away man.

I hope in good way.

And I presume it is correct when I state that I love using the terminal. It makes automatisation easy and automatisation is the main reason computers were created in the first place.

[Vic]

Yes. It is a good "hippie" thing from my younger days in the United States. It means WOW!!! man.

Vic