====== Glow - Terminal Markdown Renderer ======

===== Overview =====

[[https://github.com/charmbracelet/glow|Glow]] is a terminal-based Markdown reader and renderer. It can be used to display Markdown reports directly in a command prompt or PowerShell session with formatted headings, tables, links, code blocks and terminal colour styling.

Glow is useful when working with TapeTrack command-line utilities that produce Markdown output, as it allows the generated report to be reviewed directly from the command line without opening a separate Markdown editor.

Glow can also browse Markdown files in a directory and provides a terminal user interface (TUI) for reading documents.

===== Installation =====

==== Windows ====

Glow can be installed on Windows using Windows Package Manager (WinGet).

Open PowerShell and run:

<code powershell>
winget install charmbracelet.glow
</code>

The official Glow documentation lists WinGet as a supported Windows installation method. [[https://github.com/charmbracelet/glow|Glow documentation]]

After installation, close and reopen the PowerShell window. This is required if the installer has modified the PATH environment variable.

Verify the installation:

<code powershell>
glow --version
</code>

==== Example ====

A successful installation will report the installed Glow version.

<code>
Glow v3.0.0
</code>

The exact version may change as newer releases become available.

===== Basic Use =====

Change to the directory containing the Markdown report:

<code powershell>
cd "C:GazillaByte\Markdown"
</code>

Display a Markdown report:

<code powershell>
glow .\out.md
</code>

A second report can be displayed in the same way:

<code powershell>
glow .\out2.md
</code>

Glow does not modify the Markdown file. It reads the file and renders it in the terminal.

===== Rendering Styles =====

Glow supports terminal rendering styles. The standard styles include ''dark'' and ''light''.

To explicitly use the dark style:

<code powershell>
glow -s dark .\out.md
</code>

To use the light style:

<code powershell>
glow -s light .\out.md
</code>

When no style is specified, Glow attempts to determine whether the terminal is using a light or dark background and selects an appropriate style automatically. [[https://github.com/charmbracelet/glow|Glow documentation]]

The style affects the appearance of the rendered Markdown, including terminal colours and formatting.

===== Word Wrapping =====

Reports containing wide tables may benefit from specifying the terminal width.

For example:

<code powershell>
glow -s dark -w 120 .\out.md
</code>

The ''-w'' option specifies the maximum width used for wrapping rendered output.

===== Interactive Mode =====

Running Glow without a file argument starts its terminal user interface:

<code powershell>
glow
</code>

Glow searches the current directory and subdirectories for Markdown files and allows them to be browsed from the terminal.

===== Paging =====

Glow can use a pager when displaying Markdown:

<code powershell>
glow -p .\out.md
</code>

This is useful for reports that are longer than the visible terminal window.

===== Reading Markdown from Standard Input =====

Glow can also receive Markdown through standard input.

For example:

<code powershell>
Get-Content .\out.md | glow -
</code>

The ''-'' tells Glow to read the Markdown from standard input.

This makes it possible to place Glow after another command in a command-line processing workflow.

===== Configuration =====

If the same Glow options are used regularly, Glow provides a configuration facility:

<code powershell>
glow config
</code>

The configuration can be used to set options such as:

* Rendering style
* Word-wrap width
* Pager usage
* Mouse support in TUI mode
* Line numbers in TUI mode

See the Glow documentation for the current configuration options.

===== Testing Glow with a TapeTrack Report =====

The following procedure can be used to verify that Glow is correctly installed and can render a TapeTrack Markdown report.

First confirm the report exists:

<code powershell>
dir .\*.md
</code>

Then render it:

<code powershell>
glow -s dark .\out.md
</code>

A Markdown table produced by a TapeTrack utility should be rendered as a formatted terminal table rather than displayed as raw Markdown syntax.

===== Glow and Report Comparison =====

Glow is a Markdown renderer, not a file comparison utility.

For example, if the following files exist:

<code>
out.md
out2.md
</code>

Glow can render each report:

<code powershell>
glow -s dark .\out.md
glow -s dark .\out2.md
</code>

A separate comparison tool should be used to identify differences.

For a simple PowerShell comparison:

<code powershell>
Compare-Object (Get-Content .\out.md) (Get-Content .\out2.md)
</code>

===== Highlighting Changed Lines =====

PowerShell can be used to display ''out.md'' while colouring lines that differ from the corresponding line in ''out2.md''.

The following example colours changed lines red:

<code powershell>
$a = Get-Content .\out.md
$b = Get-Content .\out2.md

$max = [Math]::Max($a.Count, $b.Count)

for ($i = 0; $i -lt $max; $i++) {
$lineA = if ($i -lt $a.Count) { $a[$i] } else { "" }
$lineB = if ($i -lt $b.Count) { $b[$i] } else { "" }

```
if ($lineA -ne $lineB) {
    Write-Host $lineA -ForegroundColor Red
}
else {
    Write-Host $lineA
}
```

} </code>

This is a PowerShell comparison and highlighting technique. The colour is being applied by PowerShell, not by Glow.

For reports where rows remain in the same order, this provides a simple way to identify changed report lines.

For production comparison of inventory reports, comparing records by Barcode rather than simply comparing line positions is preferable if rows may be added, removed or reordered.

===== Example Environment =====

An example working directory may contain:

<code>
Test Markdown\
    out.md
    out2.md
    err.txt
    runMarkdown.bat
    Report-2026-09-18-10-29-08.pdf
</code>

The Markdown reports can then be viewed with:

<code powershell>
glow -s dark .\out.md
glow -s dark .\out2.md
</code>

===== References =====

* [[https://github.com/charmbracelet/glow|Glow]]
* [[https://github.com/charmbracelet/glow#the-cli|Glow CLI]]
* [[https://github.com/charmbracelet/glow#styles|Glow Styles]]

{{tag> technote markdown glow}}