Goal

To run Oracle SQL in Git Bash.

Assumption

You have sqlplus added to your PATH.

export PATH=${PATH}:/c/oraclexe/app/oracle/product/11.2.0/server/bin/

Problem

The option /nolog doesn’t work as expected.

$ sqlplus /nolog

SQL*Plus: Release 11.2.0.2.0 Production on Mer. Juin 7 09:43:47 2023

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

…

When SQL*Plus starts, and after CONNECT commands, the site profile
(e.g. $ORACLE_HOME/sqlplus/admin/glogin.sql) and the user profile
(e.g. login.sql in the working directory) are run.  The files may
contain SQL*Plus commands.

Refer to the SQL*Plus User's Guide and Reference for more information.

Solution

Luckily, googling “start sqlplus from git bash”, I found the solution in this related Oracle Forum post: using an extra slash will do, i.e. sqlplus //nolog.

Background

Given an ArrayList of Integers from 0 (inclusive) to 10 (exclusive) with step size 1. We use a while-loop and an Iterator<Integer> to check if this ArrayList hasNext() element, before we remove() the current element.

Problem

The code below throws an IllegalStateException.

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class UnderstandArrayListIterator {
    public static void main(String[] args) {
        List<Integer> a = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            a.add(i);
        }
        Iterator<Integer> iter = a.iterator();
        iter.next();
        while (iter.hasNext()) {
            iter.remove();
        }
    }
}

Discussion

After invoking remove(), lastRet is set to -1, so next time that this method is invoked, the condition lastRet < 0 in the if-block is satisfied, resulting in an IllegalStateException.

Dans le classique schéma pour la gestion du projet, on met le besoin du client d’abord. C’est important de l’entendre avant de commencer le traf. Sinon, on risque de perdre des heures (ou pire des jours) sur une chose que le client ne valide pas. Avant d’y mettre l’effort, il est bon de lui montrer idée générale et de lui demander un avis, afin d’éviter de lui délivrer un produit qu’il ne veut pas.

String regex replace using capture groups

Since Java SE 9, java.util.regex.Matcher’s replaceAll() method supports lambda expressions.

// import java.util.regex.*;
String varName = "random_string";
Pattern pattern = Pattern.compile("_([a-z])");
Matcher matcher = pattern.matcher(varName);
String result = matcher.replaceAll(m -> m.group(1).toUpperCase());

Source: Arvind Kumar Avinash’s answer on Stack Overflow

Check characters properties using Character’s static methods

The Character class provides some static predicates like

• isAlphabetic(char c)
• isDigit(char c)
• isLowerCase(char c)

Source: Java Character isAlphabetic() Method on Javapoint

Lien vers le diapo

Lien vers le diapo

Lien vers mon diapo sur HashMap

Background

In Customized Archetype for This Site, I was using

{{ slicestr .Name 11 | humanize | title }}

in the title attribute in my site’s archetypes/default.md, so that the first 11 characters (YYYY-MM-DD-) would be taken out if I type this command.

$ hugo new post/$(date -I)-<MY_POST_TITLE>.md

In practice, <MY_POST_TITLE> can be replaced to any title, like my-post-title.

Problem

I wanted to create my IntelliJ cheatsheet, so I typed this command.

We’ll try to stay in the project root if possible.

Find all non-hidden files to know the file structure.

$ find -path './.*' -prune -o -type f -print
./Algo-init.iml
./out/production/Algo-init/fr/eql/ai114/algo/init/demo/_1_HelloWorld.class
./src/fr/eql/ai114/algo/init/demo/_1_HelloWorld.java

• -prune returns true for the chosen path and prevents find from descending.

• -o means OR, so the paths matching -prune won’t pass through -o.

• -type f selects files, not folders.

• By default, AND is used to connect different conditions.

  [Read More]

Background

We often want to test the output with different values for a parameter. Here’s an example: we have a parameter that pandoc uses to / compile source code files to PDF / M$ Word / etc.

rm output.html; param=0; pandoc input$param.txt -o output.html; \
echo param = $param

In practice, a parameter can be a font, the font size, etc, and there can be multiple parameters.