Shell Scripting

I'm hosting mirrors of these at my domain.

• Bash Hacker's Wiki
• Zsh Manual
• Zsh Guide

I want to interactively query nix pkgs using the nix-search command provided by nix-search-cli

Not really experiaenced in cli tools any ideas to make this work ?

The document itself is paywalled like all the POSIX specifications, so here are some highlights courtesy of some comments at HackerNews, especially from a-french-anon.

• readlink and realpath
• find -print0, xargs -0 and read -d
• find -iname
• sed -E
• set -o pipefail
• $' ' strings

At the moment, I am stuck with using single-precision float, and double-precision float. So, the maximum represent-able value for single is 1<<24 while for double, it is 1<<53.

Because of this, I made the following script here - https://gist.github.com/Reptorian1125/71e3eec41e44e2e3d896a10f2a51448e .

Allow me to clarify on the script above. On the first part, rep_bin2dec does is to return the converted values into the status. So, when I do ${} or variable=${rep_bin2dec\ ???}, I get the status string.

On the second part, rep_bin2dec_base is the basis for getting rep_bin2dec to work. _rep_bin2dec_base prints the base_10M array into a string.

So, how does rep_bin2dec_base converts a big binary into big decimal?

1. If the binary image is less than dimension of 54, then the script will use 0b{} which allows me to directly convert binary to decimal, and 0b is a binary literal much in the same way that Python and C++ does it. From this point, it's pretty obvious on what to do there. So, if it less than dimension 54, this step 1 is pretty much done. If not, move on to step 2.

2. Convert the binary image as a image of base (1<<24) representing the value of that image. Note that there are two channels "[ output_value , y ]". y in this case represents the digit position in base (1<<24).

3. Make the converted image as a dynamic array image. This allows us to remove unused digits. You can look at step 2, and step 3 as converting a binary string into an array of base (1<<24) into a dynamic array. Also, note that start_value is stored. That's the very first digit.

4. Note that the number_of_decimals is the predicted number of characters after conversion of binary to decimal. And the, there's multi-threading that gets activated depending on the size of dynamic array image. decimal_conversion_array_size,result_conversion_array_size is used to define array size as they're temporary arrays to convert from base (1<<24) into base 10M. Finally, there's a new image which is going to be using base 10 million for easy printing, and set is used to add the first digit of base (1<<24) which will then be converted to base 10M.

5. On eval[-2], we are now processing the base (1<<24) image, and then convert it into base 10M. There's a implicit loop, so you can add a "for y" after begin(), and begin() can be seen as the setup code.

Some notes, copy() basically allows me to alter an array. In this case, opacity is negative, so it will add the multiplication of the positive opacity. If opacity was between 0-1, then it will get treated similar to how opacity of one layer alters a image. And the multiplication algorithm being used to convert between bases is Schönhage-Strassen multiplication, but without the FFT part.

So, here how that works.

   9   9
x  1   9
_________
  81  81
9  9
_________
1  8  8 1

Basically, it's long multiplication, and you can see that there's carrying of the remainder. 81 -> 1 (Remainder 8). 81 + 9 + R8 = 89 + 9 = 8 R ( 1+ 8 ) = 8 R 9. Then 9 + 9 is 18. So, you can see how this results in 1881.

6. After the conversion to base 10M, depending on your inputs, it'll set the status value to the decimal representation or preserves it as a base 10M for easy printing with _rep_bin2dec_base after alteration.

There's some more details, but I find it really hard to explain this.

So, my question is what are some good algorithm to print out huge binaries as decimal? I know Python is insanely good at that, but I can't seem to understand how it does that so well. I know that they do involve conversion to base 2^30 or 1<<30.

At the moment, I can convert a 90000 digits binary in .35 s, and that's bad to what I seen in Python. It's really bad with 1M binary digits.

https://discord.gg/JT6RMMfP

I've written small bash scripts before, but I bit off a little more this time, and I'm trying to program a little terminal game.

Anyway, I've run into a weird behavior. I have a function that, among other things, writes values to an array and returns either 0 or 1.

If I write echo "${name_of_array[@]}" inside the function, I see the contents of the array printed to standard output.

If I write echo "${name_of_array[@]}" outside the function immediately after executing the function, I see the contents of the array printed to standard output. (So, clearly the array is being treated as a global variable.)

But if I write the following, regardless of which value the function returns, nothing is printed to standard output but an empty line.

if ! name_of_function ; then
 echo "${name_of_array[@]}"
fi

Why is that the case? Doesn't name_of_function get executed when evaluating the if statement? Is this some special case where all variables become local?

I realize I could just assign the function's return value to a separate variable and then use that variable as the condition to the if statement, but it's less elegant, and it doesn't satisfy my curiosity. Is there any way to get the array out of the if statement alone?

It's also possible I'm an idiot and my problem is just some random punctuation somewhere.

Hello! I love broot. It's not my own project, but this blog post is, so feel free to send any questions or insults my way.

Previews:

• Drill down to change folder
• Complete a partially typed argument with a path filter
• Complete with a file-content filter

Looks like v0.90 was skipped on nushell blog, so expect minor changes from these release notes

This release of fish includes a number of improvements over fish 3.6.4, detailed below. Although work continues on the porting of fish internals to the Rust programming language, that work is not included in this release. fish 3.7.0 and any future releases in the 3.7 series remain C++ programs.

Notable improvements and fixes

• Improvements to the history pager, including:
• The history pager will now also attempt subsequence matches (#9476), so you can find a command line like git log 3.6.1..Integration_3.7.0 by searching for gitInt.
• Opening the history pager will now fill the search field with a search string if you’re already in a search (#10005). This makes it nicer to search something with ↑ and then later decide to switch to the full pager.
• Closing the history pager with enter will now copy the search text to the commandline if there was no match, so you can continue editing the command you tried to find right away (#9934).
• Performance improvements for command completions and globbing, where supported by the operating system, especially on slow filesystems such as NFS (#9891, #9931, #10032, #10052).
• fish can now be configured to wait a specified amount of time for a multi-key sequence to be completed, instead of waiting indefinitely. For example, this makes binding kj to switching modes in vi mode possible.
• The timeout can be set via the new fish_sequence_key_delay_ms variable (#7401), and may be set by default in future versions.

This release adds spreading of argument lists to command calls, better editor integration, and many bugfixes.

cross-posted from: https://beehaw.org/post/10863052

Noob question incoming, thanks in advance for any help with this!

I have a specific use case in which I want to send an automated email or text to myself once a day (the message is different each time--otherwise I would just set an alarm, lol!). I'm running Pop_OS on an old desktop computer. Where I'm stuck is getting an email to successfully send from the command line. I'm looking for easy-to-follow instructions that would help me do that, and none of the articles or videos I've come across thus far have helped.

I'm aware of Twilio and other services that send SMS messages, but I'm looking for something free. Especially since I only need to text one person (myself), and infrequently at that.

Below is my attempt to send an email with the telnet command. Nothing ever came through...

XXXXXXXX@pop-os:~$ telnet localhost smtp
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 pop-os ESMTP Exim 4.95 Ubuntu Sun, 07 Jan 2024 15:12:28 -0500
HELO gmail.com
250 pop-os Hello localhost [::1]
mail from: XXXXXXXX@gmail.com
250 OK
rcpt to: XXXXXXXX@gmail.com
250 Accepted
data
354 Enter message, ending with "." on a line by itself
Subject: Test
Body: Is this working?
.
250 OK id=1rMZW4-0002dj-Uy
quit

Three things before I'll get to the relevant details.

1. Brainfuck is a esoteric languages which uses 8 characters. I'll leave details here - https://en.wikipedia.org/wiki/Brainfuck
2. G'MIC is a language largely inspired by bash languages and one other shell scripting language, and partly inspired by C++ for JIT compilation. It's two languages in one as in one outside of JIT and one inside of JIT. It's main purpose is image processing, and it can do 3D things too, basically image-related things. It's turing-complete, so making files has been done with it. Even making a executable compiled program is possible in practice (but, I would point to doing C++ and compile there instead).
3. I am a G'MIC filters developer.

Anyways, I taken some time to code up a Brainfuck interpreter within G'MIC. It wasn't that hard to do once I understood what Brainfuck is as a language. I did one earlier than this, but I had to have users define inputs beforehand. Recently, I created rep_cin command to relieve users of doing that, and that is the closest to input() within Python or std::cin via C++.

Anyways, here's the code to my Brainfuck interpreter:

#@cli run_brainfuck_it: brainfuck_file,'_enforce_numbers_input={ 0=false | 1=true },_size_of_array>0
#@cli : Interprets Brainfuck code file within G'MIC brainfuck_interpreter.
#@cli : Default values: ,'_enforce_numbers_input=0','_size_of_array=512'
run_brainfuck_it:
    skip ${2=0},${3=512}
    it $1
    _brainfuck_interpreter $2,$3
    um run_brainfuck_it,run_brainfuck,_brainfuck_interpreter,_brainfuck_interpreter_byte_input
#@cli run_brainfuck: brainfuck_code,'_enforce_numbers_input={ 0=false | 1=true },_size_of_array>0
#@cli : Interprets Brainfuck code within G'MIC brainfuck_interpreter.
#@cli : Default values: ,'_enforce_numbers_input=0','_size_of_array=512'
run_brainfuck:
    skip ${2=0},${3=512}
    ('$1')
    _brainfuck_interpreter $2,$3
    um run_brainfuck_it,run_brainfuck,_brainfuck_interpreter,_brainfuck_interpreter_byte_input
_brainfuck_interpreter:
    # 1. Convert image into dynamic image
    resize 1,{whd#-1},1,1,-1 ({h}) append y # Convert string images into dynamic image
    name[-1] brainfuck_code                 # Name image into brainfuck_code

    # 2. Remove unused characters
    eval "
        const brainfuck_code=$brainfuck_code;
        for(p=h#brainfuck_code-2,p>-1,--p,
            char=i[#brainfuck_code,p];
            if(!(inrange(char,_'+',_'.',1,1)||(find('<>[]',char,0,1)!=-1)),
                da_remove(#brainfuck_code,p);
            );
        );
        if(!da_size(#brainfuck_code),
            run('error inval_code');
        );
        da_freeze(#brainfuck_code);
        "

    # 3. Evaluate brackets
    eval[brainfuck_code] >"
        begin(level=0;);
        i==_'['?++level:
        i==_']'?--level;
        if(level<0,run('error inv_bracks'););
        end(if(level,run('error inv_bracks');););"

    1x2  # Create 2 images of 1x1x1x1. One image is for storing print out characters, and the other is to allow inputs.
    _arg_level=1

    # 4. Create JIT code for executing brainfuck code.
    repeat h#$brainfuck_code {
        idx:=i[#0,$>]

        if $idx==_',' code_str.=run('$0_byte_input[-2]\ $1');ind_list[ind]=i#-2;                continue fi
        if $idx==_'.' code_str.=da_push(#-1,ind_list[ind]);                                     continue fi
        if $idx==_'+' code_str.=ind_list[ind]++;ind_list[ind]%=256;                             continue fi
        if $idx==_'-' code_str.=ind_list[ind]--;ind_list[ind]%=256;                             continue fi
        if $idx==_'<' code_str.=if(!inrange(--ind,0,$2,1,0),run("'error out_of_bound'"););      continue fi
        if $idx==_'>' code_str.=if(!inrange(++ind,0,$2,1,0),run("'error out_of_bound'"););      continue fi
        if $idx==_'[' code_str.=repeat(inf,if(!ind_list[ind],break(););                         continue fi
        if $idx==_']' code_str.=);                                                                       fi
    }

    # 5. Execute created JIT code. v + and v - is used to change verbosity level, not part of JIT execution. e[] is used to print into console.
    v +
    eval >begin(ind=0;ind_list=vector$2(););$code_str;end(da_freeze(#-1););
    v -

    # 6. Print out executed code result
    v + e[$^] "Brainfuck Output: "{t} v -
    remove
_brainfuck_interpreter_byte_input:
    repeat inf {
        wait         # For some reason, I had to add this to make this code work!

        if $> rep_cin "Brainfuck Interpreter - Wrong Input! Insert Integer for Argument#"$_arg_level": "
        else  rep_cin "Brainfuck Interpreter - Enter Argument#"$_arg_level" (Integers Only): "
        fi

        if $1 input:=(${}%208)+_'0'
        else  input=${}
        fi

        if isint($input) break fi
    }

    if $1 
        v + e[$^] "Brainfuck Interpreter Inserted Argument#"$_arg_level": "{$input-_'0'} v -
    else
        input%=256
        v + e[$^] "Brainfuck Interpreter Inserted Argument#"$_arg_level": "$input" :: "{`$input`} v -
    fi

    _arg_level+=1
    f[-1] $input

And the CLI test:

C:\Users\User\Documents\G'MIC\Brainfuck Interpreter>gmic "brainfuck_interpreter.gmic" run_brainfuck \">,>,<<++++++[>-------->--------<<-]>[>[>+>+<<-]>[<+>-]<<-]>[-]>+>>++++++++++<[->-[>>>]++++++++++<<+[<<<]>>>>]<-<++++++++++>>>[-<<<->>>]<<<<++++++[>++++++++>[++++++++>]<[<]>-]>>[.<<]<[<<]>>.\",1
[gmic]./ Start G'MIC interpreter (v.3.3.3).
[gmic]./ Input custom command file 'brainfuck_interpreter.gmic' (4 new, total: 4806).
[gmic]./ Brainfuck Interpreter Inserted Argument#1: 31
[gmic]./ Brainfuck Interpreter Inserted Argument#2: 3
[gmic]./ Brainfuck Output: 93
[gmic]./ End G'MIC interpreter.

If you have the answer please leave it here in the comments #javascript #php #programming

This is not my work, but the author (same author as zsh-abbr) posted it elsewhere and it looks good to me.

In his words:

What is zsh-test-runner? A simple testing framework for zsh, and to a degree —thanks to zsh's emulation of other shells— csh, ksh, and sh.

The immediately noticeable difference between zsh-test-runner and other shell script unit test frameworks is it doesn't have a DSL. zsh-test-runner relies entirely on the shell's own testing. For those familiar with other frameworks: nothing like ShellSpec's Describe … When call … The output should, or shUnit2's assertEquals, or ZUnit's assert; zsh-test-runner is closer to Bats if you were to restrict yourself to core and not use helper libraries (there's nothing like bats-assert's assertEquals or bats-file's assert_dir_exists).

Why no special syntax? It means there's little new to learn— For example, if you know how to test numeric equality in your shell, you know how to test equality in zsh-test-runner; if you don't, there are community resources available. It means every possible test is supported equally out of the box— zsh-test-runner is a newcomer, but there are no "shoot my assertion method isn't supported" blockers. It means the cost of porting homegrow framework-less tests to zsh-test-runner is about as low as can be— generally speaking, my_cool_test_code becomes ztr test 'my_cool_test_code'. It means tests can live comfortably in one LOC, making zsh-test-runner pleasant to use in the terminal.

It contains some breaking changes.