### Install on Ubuntu Linux

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/search_server/README.md

Steps to install Open Semantic Search Server on Ubuntu Linux.

```bash
sudo apt install ./open-semantic-search-server*.deb
q
```

--------------------------------

### Switch to root user in terminal

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/desktop_search/README.md

Command to get full root access in the terminal application.

```bash
su
```

--------------------------------

### Install on Debian GNU/Linux

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/search_server/README.md

Steps to install Open Semantic Search Server on Debian GNU/Linux.

```bash
su
dpkg --install open-semantic-search-server*.deb
apt-get -f install
```

--------------------------------

### Start the build VM

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Start the build VM without using the full build script.

```bash
vagrant up
```

--------------------------------

### Install vagrant-reload plugin

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Install the vagrant-reload plugin for Vagrant.

```bash
vagrant plugin install vagrant-reload
```

--------------------------------

### Start Solr index service

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/cmd/README.md

Command to start the Solr index service.

```bash
service solr start
```

--------------------------------

### Index some files

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/search_server/README.md

Command to index files using Open Semantic Search.

```bash
opensemanticsearch-index-dir /usr/share/doc
```

--------------------------------

### Example: Process function implementation

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

An example implementation of the 'process' function within a plugin, showing how to access text size from parameters and append it to the 'textsize' facet in data.

```python
# ...
   def process ( parameters={}, data={} ):
      # do some analyses, i.e. with text
      textsize = parameters[text'].size

      #write some analysis results to the index into a facet
      opensemanticsearch_connector.append(data, facet='textsize', values=textsize)

      #return
      return parameters, data
```

--------------------------------

### Install Python dependencies from requirements.txt

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/README.md

This command installs Python dependencies listed in the requirements.txt file, typically used during the installation of Debian/Ubuntu packages or Docker builds.

```bash
pip3 install -r /usr/lib/python3/dist-packages/opensemanticetl/requirements.txt
```

--------------------------------

### Access the search interface

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/search_server/README.md

URL to access the Open Semantic Search interface in a browser.

```bash
http://localhost/search
```

--------------------------------

### Run docker containers

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/README.md

Starts all Docker images, dependencies, and services using docker-compose.

```bash
docker-compose up
```

--------------------------------

### Install Open Semantic Search Server

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/download/README.md

Command to install the Open Semantic Search Server package on Debian or Ubuntu based Linux systems.

```bash
apt install open-semantic-search
```

--------------------------------

### Example command line usage for custom configuration

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/etl/README.md

This command shows how to specify a custom configuration file for the ETL process.

```bash
etl-file --config */etc/etl/MyCustomConfig* *filename*
```

--------------------------------

### Commandline Usage

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/connector/rss/README.md

Example of using the commandline to index an RSS feed.

```bash
opensemanticsearch-index-rss *http://www.opensemanticsearch.org/feed*
```

--------------------------------

### Exit console

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/desktop_search/README.md

Command to exit the root console session.

```bash
exit
```

--------------------------------

### Install Scantailor

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/config/ocr/README.md

Command to install the Scantailor package on Debian-based Linux distributions.

```bash
apt-get install scantailor
```

--------------------------------

### CSV Export Example

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/etl/export/csv/README.md

Example of setting the Solr result writer to CSV format using the `wt` parameter.

```bash
localhost:8983/solr/core1/select?q=*:*&wt=csv
```

--------------------------------

### Set root password

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/install/desktop_search/README.md

Command to set a root password after logging in as root without a password.

```bash
passwd
```

--------------------------------

### Example: Aborting processing

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

Shows how to set a parameter to 'True' to stop further processing and indexing of the current document.

```python
parameters['break'] = True
```

--------------------------------

### Example: Writing to data facet

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

Demonstrates how to add custom tags and location information to the 'data' variable for indexing.

```python
data['tags'] = 'myTopic'
data['location'] = 'Berlin'
```

--------------------------------

### Configure remote API address

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/trigger/filemonitoring/README.md

Example configuration snippet showing how to set the remote search server API address.

```python
config['api'] = "http://192.168.1.1/search-apps/api"
```

--------------------------------

### Example of a custom regular expression for dollar amounts

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/enhancer/regex/README.md

This example shows how to define a regular expression to capture dollar amounts and assign them to a specific facet named 'dollar_ss'. Lines starting with '#' are comments.

```regex
# Write text like *1000.00 $* or *100$* to the facet *dollar_ss*
[0-9]+[\.,]?[0-9]*[:blank:]*\$ dollar_ss
```

--------------------------------

### Example: Reading parameters

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

Shows how to print the 'parameters' variable, which contains configuration and analysis results from previous plugins.

```python
print parameters
```

--------------------------------

### Get a shell inside the VM

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Get a shell running inside the VM.

```bash
vagrant ssh
```

--------------------------------

### Build the VM

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Build the Open Semantic Desktop Search VM using the build script.

```bash
./build.sh
```

--------------------------------

### Proximity Search Example

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/search/fuzzy/README.md

Example of how to perform a proximity search to find name variants with additional words in between.

```text
"Barack Obama"~2
```

--------------------------------

### Example: Reading config options

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

Demonstrates how a plugin can read custom configuration options passed from the connector's configuration.

```python
config['myOwnEnhancerName'] = 'Own Enhancer'
```

--------------------------------

### Get root access inside the VM

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Get root access within the VM shell.

```bash
sudo su
```

--------------------------------

### Install Tesseract OCR

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/admin/config/ocr/README.md

Command to install the Tesseract OCR package on Debian-based Linux distributions.

```bash
apt-get install tesseract-ocr
```

--------------------------------

### Index RDF file using command line tool

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/connector/rdf/README.md

Example of using the opensemanticsearch-index-file command line tool to index an RDF file.

```bash
opensemanticsearch-index-file
```

--------------------------------

### Example: Data structure after enhancer

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

Shows an example of the 'data' variable after several enhancer plugins have added their results, including content type, filesize, tags, and email addresses.

```json
{
 'content_type': 'application/pdf',
 'filesize': 12345,
 'tags': {'Open Source', 'Free software'},
 'email_ss': { 'info@opensemanticsearch.org', 'support@opensemanticsearch.org' }
}
```

--------------------------------

### Example Python Plugin Structure

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/dev/enhancer/python/README.md

This is a basic example of a Python plugin that processes parameters and data, appends a calculated value to the data facet, and returns the processed parameters and data.

```python
import etl

class myOwnEnhancerName(object):

   def process ( parameters={}, data={} ):

      # do some analyses, i.e. with text
      uri_length = len ( parameters['id'] )

      #write some analysis results to the index into a facet
      etl.append(data, facet='uri_length_i', values=uri_length)

      #return results
      return parameters, data
```

--------------------------------

### Example of extracting a specific group from a regular expression

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/enhancer/regex/README.md

This example demonstrates how to extract only a specific part (a captured group) of a regular expression match. Here, it extracts the numerical part of a size measurement.

```regex
Size of ([0-9]+)[:blank:]?m size_ss 1
```

--------------------------------

### REST-API Usage

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/connector/rss/README.md

Example of using the REST-API to index an RSS feed.

```bash
http://127.0.0.1/search-apps/api/index-rss?uri=*http://www.opensemanticsearch.org/feed*
```

--------------------------------

### Command line tool for indexing

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/search/README.md

This command can be used to start a crawl for indexing documents if it's not done automatically.

```bash
searchd --crawl /path/to/your/documents
```

--------------------------------

### Open Semantic ETL Python Script Example

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/connector/db/README.md

Example of how to use Open Semantic ETL to import data from a SQL database to a search index. The script should write columns to the 'data' variable (a Python dictionary) and then call etl.process(data=data).

```python
import open_semantic_etl as etl

# ... (code to fetch data from SQL database) ...

data = {
    "column1": "value1",
    "column2": "value2"
}

etl.process(data=data)
```

--------------------------------

### Build docker images

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/README.md

Builds the Docker images using the default docker-compose configuration.

```bash
docker-compose build
```

--------------------------------

### Replay playbook

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/src/open-semantic-desktop-search/README.md

Replay the Ansible playbook after fixing bugs.

```bash
vagrant provision
```

--------------------------------

### Boolean Operators

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/docs/doc/search/operators/README.md

Examples of using AND, OR, and NOT/(-) operators to combine search terms.

```text
search engine
search AND engine
```

```text
search OR research
```

```text
search -engine
search NOT engine
search AND NOT engine
```

--------------------------------

### Integration tests - Build and Run

Source: https://github.com/opensemanticsearch/open-semantic-search/blob/master/README.md

Builds and runs integration tests within the docker-compose environment.

```bash
docker-compose -f docker-compose.etl.test.yml build
docker-compose -f docker-compose.etl.test.yml up
```