# Renaming

it does not even require the program `rename`

here is the command to get everything *lowercase* and switch **" " (space)** to "_" (underscore):

```bash
find . -depth -exec bash -c '
    for path do
        dir=${path%/*}
        file=${path##*/}
        newfile=$(echo "$file" | tr "[:upper:]" "[:lower:]" | tr " " "_")
        if [ "$file" != "$newfile" ]; then
            mv -i -- "$path" "$dir/$newfile"
        fi
    done
' _ {} +
```

here is the command to get everything *lowercase* and switch **"-" (hyphen)** to "_" (underscore):

```bash
find . -depth -exec bash -c '
    for path do
        dir=${path%/*}
        file=${path##*/}
        newfile=$(echo "$file" | tr "[:upper:]" "[:lower:]" | tr "-" "_")
        if [ "$file" != "$newfile" ]; then
            mv -i -- "$path" "$dir/$newfile"
        fi
    done
' _ {} +
```

---

# ImageMagick

to crop images to cinematic aspect ratio:

```bash
convert input.jpg -gravity center -crop 2.39:1 +repage output.jpg
```

to resize images and then crop them to cinematic aspect ratio:

```bash
convert input.jpg -resize 1920x1920^ -gravity center -crop 2.39:1 +repage output.jpg
```

to trim borders:

```bash
convert input.jpg -trim output.jpg
```

trim borders of all images in directory:

```bash
mogrify -trim *.jpg
```

---

# Exiftool

to get timestamps based on filename:
```bash
exiftool -r -overwrite_original -if 'not defined $DateTimeOriginal' "-AllDates<Filename" /path/to/your/folder
```

to rename pictures based on their date taken:

```bash
exiftool '-FileName<${DateTimeOriginal}.%e' -d IMG_%Y%m%d_%H%M%S .
```

---

# Vim

## Movements

**'h', 'j', 'k', 'l'** are the same as ←, ↓, ↑, →

- **gg** goes to the top of the document
    
- **G** goes to the bottom of the document
    
- **[#g](app://obsidian.md/index.html#g)** number and g goes to that line/page
    
- **$** goes to the end of the line
    
    - **g_** goes to the last character of the line
- **0** goes to the beginning of the line
    
    - **^**goes back to the first character of the line
- **}** goes down by paragraphs
    
- **{** goes up by paragraphs
    
- **Ctrl+d** goes down by half a page
    
- **Ctrl+u** goes up by half a page
    
- **/** searches, n moves forwards, N backwards
    
- **?** searches, n moves backwards, N forwards
    
- **w** moves forwards by words (1st letter)
    
    - **W** skips punctuation marks
- **b** moves backwards by words (1st letter)
    
    - **B** skips punctuation marks
- **e** moves forwards by words (last letter)
    
    - **E** skips punctuation marks
- **ge** moves backwards by words (last letter)
    
    - **gE** skips punctuation marks

## Modes

- Normal mode
    
- Insert mode
    
- Visual mode
    
- Command line

---

# FFmpeg

Slideshow with background music by Luke Smith:

```bash
cat *.jpg | ffmpeg -framerate 0.25 -f image2pipe -i SONG.mp3 -acodec copy -output.mkv
```

Slider script starting from an audio, by Luke Smith:

```bash
#!/bin/sh

# Give a file with images and timecodes and creates a video slideshow of them.
#
# Timecodes must be in format 00:00:00.
#
# Imagemagick and ffmpeg required.

# Application cache if not stated elsewhere.
cache="${XDG_CACHE_HOME:-$HOME/.cache}/slider"

while getopts "hvrpi:c:a:o:d:f:t:e:x:s:" o; do case "${o}" in
    c) bgc="$OPTARG" ;;
    t) fgc="$OPTARG" ;;
    f) font="$OPTARG" ;;
    i) file="$OPTARG" ;;
    a) audio="$OPTARG" ;;
    o) outfile="$OPTARG" ;;
    d) prepdir="$OPTARG" ;;
    r) redo="$OPTARG" ;;
    s) ppt="$OPTARG" ;;
    e) endtime="$OPTARG" ;;
    x) res="$OPTARG"
        echo "$res" | grep -qv "^[0-9]\+x[0-9]\+$" &&
            echo "Resolution must be dimensions separated by a 'x': 1280x720, etc." &&
            exit 1 ;;
    p) echo "Purge old build files in $cache? [y/N]"
        read -r confirm
        echo "$confirm" | grep -iq "^y$" && rm -rf "$cache" && echo "Done."
        exit ;;
    v) verbose=True ;;
    *) echo "$(basename "$0") usage:
  -i  input timecode list (required)
  -a  audio file
  -c  color of background (use html names, black is default)
  -t  text color for text slides (white is default)
  -s  text font size for text slides (150 is default)
  -f  text font for text slides (sans serif is default)
  -o  output video file
  -e  if no audio given, the time in seconds that the last slide will be shown (5 is default)
  -x  resolution (1920x1080 is default)
  -d  tmp directory
  -r  rerun imagemagick commands even if done previously (in case files or background has changed)
  -p  purge old build files instead of running
  -v  be verbose" && exit 1

esac done

# Check that the input file looks like it should.
{ head -n 1 "$file" 2>/dev/null | grep -q "^00:00:00    " ;} || {
    echo "Give an input file with -i." &&
    echo "The file should look as this example:

00:00:00    first_image.jpg
00:00:03    otherdirectory/next_image.jpg
00:00:09    this_image_starts_at_9_seconds.jpg
etc...

Timecodes and filenames must be separated by Tabs." &&
    exit 1
    }

if [ -n "${audio+x}" ]; then
    # Check that the audio file looks like an actual audio file.
    case "$(file --dereference --brief --mime-type -- "$audio")" in
        audio/*) ;;
        *) echo "That doesn't look like an audio file."; exit 1 ;;
    esac
    totseconds="$(date '+%s' -d $(ffmpeg -i "$audio" 2>&1 | awk '/Duration/ {print $2}' | sed s/,//))"
fi

prepdir="${prepdir:-$cache/$file}"
outfile="${outfile:-$file.mp4}"
prepfile="$prepdir/$file.prep"

[ -n "${verbose+x}" ] && echo "Preparing images... May take a while depending on the number of files."
mkdir -p "$prepdir"

{
while read -r x;
do
    # Get the time from the first column.
    time="${x%%    *}"
    seconds="$(date '+%s' -d "$time")"
    # Duration is not used on the first looped item.
    duration="$((seconds - prevseconds))"

    # Get the filename/text content from the rest.
    content="${x#*    }"
    base="$(basename "$content")"
    base="${base%.*}.jpg"

    if [ -f "$content" ]; then
        # If images have already been made in a previous run, do not recreate
        # them unless -r was given.
        { [ ! -f "$prepdir/$base" ] || [ -n "${redo+x}" ] ;} &&
            convert -size "${res:-1920x1080}" canvas:"${bgc:-black}" -gravity center "$content" -resize 1920x1080 -composite "$prepdir/$base"
    else
        { [ ! -f "$prepdir/$base" ] || [ -n "${redo+x}" ] ;} &&
            convert -size "${res:-1920x1080}" -background "${bgc:-black}" -fill "${fgc:-white}" -font "${font:-Sans}" -pointsize "${ppt:-150}" -gravity center label:"$content" "$prepdir/$base"
    fi

    # If the first line, do not write yet.
    [ "$time" = "00:00:00" ] || echo "file '$prevbase'
duration $duration"

    # Keep the information required for the next file.
    prevbase="$base"
    prevtime="$time"
    prevseconds="$(date '+%s' -d "$prevtime")"
done < "$file"
# Do last file which must be given twice as follows
endtime="$((totseconds-seconds))"
echo "file '$base'
duration ${endtime:-5}
file '$base'"
} > "$prepfile"
if [ -n "${audio+x}" ]; then
    ffmpeg -hide_banner -y -f concat -safe 0 -i "$prepfile" -i "$audio" -c:a aac -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
else
    ffmpeg -hide_banner -y -f concat -safe 0 -i "$prepfile" -vsync vfr -c:v libx264 -pix_fmt yuv420p "$outfile"
fi

# Might also try:
# -vf "fps=${fps:-24},format=yuv420p" "$outfile"
# but has given some problems.
```

---

# Hugo

## Frontmatters

my **minimal** frontmatter:

```yaml
title: 'Title'
date: 2022-05-18T18:51:59+01:00
tags: ["Tag1", "Tag2", "Tag3"]
draft: false
description: "Description"
cover:
    image: "cov/image.jpg"
```

my *usual* frontmatter:

```yaml
title: 'Title'
date: 2022-05-18T18:51:59+01:00
slug:
tags: ["Tag1", "Tag2", "Tag3"]
author: "Tommaso Zanette"
draft: false
description: "Description"
hidemeta: false
disableShare: false
searchHidden: false
cover:
    image: "cov/image.jpg" # image path/url
    alt: "image" # alt text
    caption: "Caption" # display caption under cover
```

## Shortcodes

image shortcode:

```go
{{< figure align=center src="/img/image.jpg" title="Caption" link="https://" target="_blank">}}
```

youtube custom shortcode (it uses video id):

```html
{{<ytpl PLG3Uw74TA0VaPGvleLFuzS5rdhKtCzKoM>}}
```