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14 changes: 8 additions & 6 deletions GNU Parallel.md
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Expand Up @@ -20,25 +20,27 @@ Typical use cases include:

### Converting Files in Parallel

> **Known issue:** the `imagemagick` module is currently unavailable on Easley. A fix is expected within a day — until then, skip this example.

The following example converts all `.csv` files into `.txt` files.
The following example converts all `.png` files in the current directory into `.jpg` files, using ImageMagick's `convert` for the actual per-file conversion and GNU Parallel to run many conversions at once.

```bash
module load parallel
module load imagemagick

find . -name "*.csv" | parallel convert {} {.}.txt
find . -name "*.png" | parallel convert {} {.}.jpg
```

This command:

1. Finds all files ending in `.csv`
1. Finds all files ending in `.png`
2. Passes each file to GNU Parallel
3. Executes conversions concurrently

`{}` represents the full filename and `{.}` removes the extension.

Note: ImageMagick's `convert` only understands image formats — it can't be used to turn arbitrary files like `.csv` into `.txt`. For converting non-image data between formats in parallel, replace `convert {} {.}.jpg` with whatever conversion command is appropriate for your file type (e.g. a script or a different CLI tool); GNU Parallel itself doesn't care what command it's fanning out.

`convert` prints a one-time deprecation warning in this version of ImageMagick (IMv7) suggesting `magick` instead — both work identically here, but `magick {} {.}.jpg` is the more future-proof spelling if you're starting fresh.

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### Compressing and Decompressing Files
Expand Down Expand Up @@ -358,4 +360,4 @@ sbatch python_parallel.slurm

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*This QuickByte was updated and validated on June 23, 2026.*
*This QuickByte was updated and validated on August 3, 2026.*