forked from data.coop/website
98 lines
1.9 KiB
Markdown
98 lines
1.9 KiB
Markdown
---
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title: "Script to add a page-level variable to content front matter in hugo"
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date: 2018-10-10T12:43:20-05:00
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publishdate: 2018-10-10
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lastmod: 2018-10-11
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draft: false
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tags: ["hugo", "command-line", "awk"]
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---
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This was originally a question posed on the [hugo discussion forums](https://discourse.gohugo.io/t/set-frontmatter-params-in-list-template/14645).
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The user wanted to loop through all her content files and add a `weight` page-level variable to the front matter. The value of `weight` needed to be the first 2 characters of the content filename, since her content was named like `01_content.md`, `02_content.md`, etc.
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She then wanted to `range` through her pages by their weight, like so:
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```go
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{{ range .Pages.ByWeight }}
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<!-- some code -->
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{{ end }}
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```
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## The script
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```bash
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#!/bin/bash
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for file in *.md; do
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weight=${file:0:2}
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awk -v weight=$weight '/---/{
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count++
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if(count == 2){
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sub("---","weight: " weight "\n---",$0)
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}
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}
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{print}' $file > tmp && mv tmp $file
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done
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```
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## Explained
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Loop through all files in the directory with extension `.md`:
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```bash
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for file in *.md; do
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# ...
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done
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```
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Set a variable using the first 2 characters of the filename:
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```bash
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weight=${file:0:2}
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```
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Call an `awk` program and pass it a `weight` variable:
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```bash
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awk -v weight=$weight
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```
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When the `awk` program encounters the 2nd occurrence of `---` (which is how you end front matter in YAML), it inserts the `weight` page-level variable on the line above:
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```bash
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'/---/{
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count++
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if(count == 2){
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sub("---","weight: " weight "\n---",$0)
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}
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}
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{print}'
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```
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Redirect the output of the `awk` program to a tmp file, then overwrite the original content file with the tmp file:
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```bash
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> tmp && mv tmp $file
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```
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## Result
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Original `01_content.md`:
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```yml
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---
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title: "Some title"
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draft: false
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---
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```
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Updated `01_content.md`:
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```yml
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---
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title: "Some title"
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draft: false
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weight: 01
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---
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``` |