# CLI Cheatsheet

## Contents

- [Drupal / Drush](#drupal--drush)
- [Text Processing](#text-processing)
- [Torrents](#torrents)
- [PDF Tools](#pdf-tools)
- [PDF Sheet Music](#pdf-sheet-music)
- [Audiobooks](#audiobooks)
- [Large File Transfer (rclone)](#large-file-transfer-rclone)

---

## Drupal / Drush

> Note: These SQL queries target the Drupal 7 schema (`node_type` table). They won't work as-is on Drupal 8+.

### List content types with node counts

```bash
drush sqlq 'select count(node.nid) as node_count, node_type.type
            from node
            inner join node_type on node.type = node_type.type
            group by node_type.type'
```

### Filter results by keyword (e.g. "2014")

```bash
drush sqlq 'select count(node.nid) as node_count, node_type.type
            from node
            inner join node_type on node.type = node_type.type
            group by node_type.type' | grep 2014
```

---

## Text Processing

### Find and replace inside files (perl)

```bash
# Single file type in current directory
perl -pi -w -e 's/SEARCH_FOR/REPLACE_WITH/g;' *.txt

# Recursively across all file types
perl -pi -w -e 's/thex/robertsonlibrary/g;' **/*.*
```

### Find and replace in file names

```bash
# Rename files matching a pattern, verbose output shows what changed
rename 's/livero/lives/g' **/*.* -v
```

---

## Torrents

### Download via magnet link (aria2c)

```bash
# aria2c is a lightweight multi-protocol download utility
aria2c -d ~/Downloads "magnetlink"
```

---

## PDF Tools

### OCR a PDF (ocrmypdf)

```bash
# Standard: optimize output, skip pages that already have a text layer
ocrmypdf --optimize 3 --skip-text input.pdf output.pdf

# Aggressive: force re-OCR even if a text layer exists (useful for corrupt/bad layers),
# set DPI manually, use page segmentation mode 1 (automatic with OSD)
ocrmypdf --optimize 3 --image-dpi 300 --output-type pdf \
         --force-ocr --tesseract-pagesegmode 1 input.pdf output.pdf
```

### Downsample a PDF to 72dpi (Ghostscript)

```bash
# Single file
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 \
   -dPDFSETTINGS=/screen \
   -dNOPAUSE -dQUIET -dBATCH \
   -sOutputFile=output.pdf input.pdf

# Batch - processes all PDFs in current folder, preserves original filenames
mkdir -p downsampled
for f in *.pdf *.PDF; do
    [ -f "$f" ] || continue
    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen \
       -dNOPAUSE -dBATCH -dQUIET \
       -sOutputFile="downsampled/$f" \
       "$f"
done
```

### Check image DPI in PDFs (pdfimages)

```bash
# Print image info to terminal
for f in *.pdf *.PDF; do
    echo "=== $f ==="
    pdfimages -list "$f"
    echo ""
done

# Save output to images_list.txt instead (appends; delete the file first to start fresh)
for f in *.pdf *.PDF; do
    [ -f "$f" ] || continue
    echo "=== $f ===" >> images_list.txt
    pdfimages -list "$f" >> images_list.txt
    echo "" >> images_list.txt
done
```

### Scan for CCITT encoding

CCITT is a fax-era compression format - this flags PDFs that may cause compatibility issues.

```bash
for f in *.pdf *.PDF; do
    [ -f "$f" ] || continue
    if pdfimages -list "$f" 2>/dev/null | grep -q " ccitt "; then
        echo "$f uses CCITT"
    fi
done
```

---

## PDF Sheet Music

### Check page size

```bash
pdfinfo filename.pdf
```

### Resize to letter

```bash
gs -sDEVICE=pdfwrite \
   -sPAPERSIZE=letter \
   -dFIXEDMEDIA \
   -dPDFFitPage \
   -dNOPAUSE -dBATCH \
   -sOutputFile=output.pdf input.pdf
```

### Batch resize to letter

```bash
mkdir -p resized_music
for f in *.pdf; do
    gs -sDEVICE=pdfwrite -sPAPERSIZE=letter -dFIXEDMEDIA -dPDFFitPage \
       -dNOPAUSE -dBATCH -sOutputFile="resized_music/$f" "$f"
done
```

---

## Audiobooks

### Split an m4b into MP3 chapters (m4b-tool via Docker)

`cd` to the desired directory, create an `input` dir, put the m4b file in it, then run:

```bash
docker run --rm -it \
  -v "$(pwd)":/data \
  sandreas/m4b-tool \
  split "/data/input/The Haunting of Hill House.m4b" \
  --audio-format mp3 \
  --audio-bitrate 128k \
  --audio-channels 1 \
  --output-dir "/data/split" \
  -vv
```

### Split an m4b by chapter (ffmpeg)

Reads chapter end times with ffprobe and writes `chapter_000.mp3`, `chapter_001.mp3`, etc.

```bash
ffmpeg -i Chaos.m4b -map 0:a -f segment \
  -segment_times $(ffprobe -i Chaos.m4b -show_chapters -loglevel error \
    | grep end_time | cut -d= -f2 | tr '\n' ',' | sed 's/,$//') \
  -c:a libmp3lame -q:a 2 chapter_%03d.mp3
```

---

## Large File Transfer (rclone)

### Copy to Google Drive

```bash
rclone copy file_location file_destination \
  --progress \
  --transfers 4 \
  --checkers 8 \
  --retries 10 \
  --low-level-retries 20 \
  --drive-chunk-size 64M \
  --log-file rclone.log \
  --log-level INFO
```