Pull Request #54 Suggestions

Model 1

Ensure target directory exists.

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The current implementation does not create the target directory for wallpapers. If the directory does not exist, the `wget` command will fail for all downloads. You should ensure the target directory is created before attempting to download files into it.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"
mkdir -p "$TARGET_DIR"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Improve wget command robustness.

general

File: files/scripts/24-wallpapers.sh | Language: bash

The `wget` command in the `xargs` pipe does not have any flags to prevent it from failing loudly on errors, retrying, or running quietly. This can lead to a noisy and potentially fragile script. It is better to use `wget` with flags to suppress output, continue downloads, and prevent retries for a cleaner and more robust execution.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -q -c -nc -P "$TARGET_DIR" "{}"

Model 2

Ensure target directory exists

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The script doesn't check if the target directory exists before downloading files. If the directory doesn't exist, the downloads will fail. Add a mkdir command with the -p flag to ensure the target directory exists.
Existing Code
#!/usr/bin/env bash

set -oeux pipefail

URLS=(
  # ... URL list ...
)

TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
#!/usr/bin/env bash

set -oeux pipefail

URLS=(
  # ... URL list ...
)

TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"
mkdir -p "$TARGET_DIR"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Model 3

Correctly enable pipefail shell option.

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The `set` command is not enabling the `pipefail` option correctly. The current syntax `set -oeux pipefail` treats `pipefail` as a positional argument ($1) instead of setting the shell option. This means that in a pipeline like `cmd1 | cmd2`, if `cmd1` fails but `cmd2` succeeds, the pipeline will still be considered successful, potentially masking errors. Use `set -euxo pipefail` to correctly enable `errexit` (-e), `nounset` (-u), `xtrace` (-x), and `pipefail` (-o pipefail) options.
Existing Code
set -oeux pipefail
Improved Code
set -euxo pipefail

Make wallpaper downloads idempotent.

general

File: files/scripts/24-wallpapers.sh | Language: bash

The `wget` command currently re-downloads files if they already exist, potentially creating numbered duplicates (e.g., `image.bmp.1`). Add the `-nc` (`--no-clobber`) option to `wget` to prevent downloading files if they already exist in the target directory. This makes the script idempotent and avoids unnecessary downloads or disk space consumption on subsequent runs.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -nc -P "$TARGET_DIR" "{}"

Ensure target directory exists first.

general

File: files/scripts/24-wallpapers.sh | Language: bash

Before attempting to download files, explicitly create the target directory using `mkdir -p`. This ensures the directory exists. Additionally, checking for write permissions to `TARGET_DIR` can provide a clearer error message if the script lacks necessary permissions, rather than letting individual `wget` processes fail.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

mkdir -p "$TARGET_DIR" || { echo "Error: Failed to create directory '$TARGET_DIR'. Aborting." >&2; exit 1; }
if [ ! -w "$TARGET_DIR" ]; then
  echo "Error: Directory '$TARGET_DIR' is not writable. Aborting." >&2
  exit 1
fi

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Model 4

Add checksum validation for downloads.

security

File: files/scripts/24-wallpapers.sh | Language: bash

The script downloads files from an external source without verifying their integrity using checksums. This is a security risk, as a malicious or corrupted file could be downloaded and placed into the system's wallpaper directory. To mitigate this, each file should be verified against a known SHA256 hash after download.
Existing Code
URLS=(
  "https://archive.org/download/microsoft-windows-wallpapers-pictures/1-2.%20Windows%203.1x%20and%20NT%203.x/256color%20%28large%29.bmp"
  "https://archive.org/download/microsoft-windows-wallpapers-pictures/1-2.%20Windows%203.1x%20and%20NT%203.x/Concrete.bmp"
  ...
  "https://archive.org/download/microsoft-windows-wallpapers-pictures/1-1.%20Windows%203.0/WEAVE.BMP"
)

TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
BASE_URL="https://archive.org/download/microsoft-windows-wallpapers-pictures"

# Format: "SHA256_HASH  SUB_PATH/FILENAME"
# Note: Checksums are placeholders and MUST be replaced with actual file hashes.
WALLPAPERS=(
  "placeholder_sha256_hash  1-2.%20Windows%203.1x%20and%20NT%203.x/256color%20%28large%29.bmp"
  "placeholder_sha256_hash  1-2.%20Windows%203.1x%20and%20NT%203.x/Concrete.bmp"
  ...
  "placeholder_sha256_hash  1-1.%20Windows%203.0/WEAVE.BMP"
)

TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

for item in "${WALLPAPERS[@]}"; do
  read -r sha256_hash path <<< "$item"
  filename=$(basename "$path")
  # URL decode filename for checksum verification, wget does this automatically
  decoded_filename=$(printf '%b' "${filename//%/\\x}")
  wget -q -P "$TARGET_DIR" "${BASE_URL}/${path}"
  echo "${sha256_hash}  ${TARGET_DIR}/${decoded_filename}" | sha256sum -c -
done

Model 5

Ensure target directory exists before download.

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

If `$TARGET_DIR` does not exist, `wget` will fail to save the files. Add a directory creation step before downloading to prevent errors when the directory does not already exist.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
mkdir -p "$TARGET_DIR"
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Model 6

Fix invalid set options

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

Using `-o` together with concatenated short flags is invalid and causes the script to abort immediately. Replace it with the conventional `set -euo pipefail` to correctly enable *errexit*, *nounset*, and *pipefail* while avoiding a startup failure.
Existing Code
set -oeux pipefail
Improved Code
set -euo pipefail

Create download directory first

general

File: files/scripts/24-wallpapers.sh | Language: bash

Ensure the target directory exists before downloading; without it, every `wget` call fails with “No such file or directory.” Create the directory with `mkdir -p` right after defining `TARGET_DIR`.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"
mkdir -p "$TARGET_DIR"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Model 7

Create target directory before downloading

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The script will fail if the target directory doesn't exist. Create the directory before attempting downloads to ensure the script runs successfully.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

mkdir -p "$TARGET_DIR"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Add download failure error handling

general

File: files/scripts/24-wallpapers.sh | Language: bash

Add error handling to detect and report download failures. Without proper error handling, partial download failures may go unnoticed.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
if ! printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"; then
    echo "Error: Some wallpaper downloads failed" >&2
    exit 1
fi

Model 8

Correct shell option flags

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The `set` flags are malformed and may not enable the intended options. Use the correct combination to fail on errors, undefined variables, and pipe failures while preserving debugging.
Existing Code
set -oeux pipefail
Improved Code
set -euo pipefail -x

Create target directory

general

File: files/scripts/24-wallpapers.sh | Language: bash

Ensure the target directory exists before downloading to avoid errors when `wget` writes files. Create the directory with `mkdir -p`.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"
mkdir -p "$TARGET_DIR"

Skip existing downloads

general

File: files/scripts/24-wallpapers.sh | Language: bash

Add the `-nc` flag to `wget` to skip downloading files that already exist, preventing unnecessary overwrites and re-fetches.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -nc -P "$TARGET_DIR" "{}"

Model 9

Ensure target directory exists

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The script doesn't verify that the target directory exists before downloading files. This could cause wget to fail if the directory structure isn't already in place. Add a directory creation step before the download operation.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

mkdir -p "$TARGET_DIR"
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Add robust download options

general

File: files/scripts/24-wallpapers.sh | Language: bash

The download command lacks error handling and could silently fail for individual URLs. Consider adding wget options to handle failures gracefully and provide better feedback on download status.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget --no-clobber --timeout=30 --tries=3 -P "$TARGET_DIR" "{}"

Model 10

Create directory before downloading files

possible issue

File: files/scripts/24-wallpapers.sh | Language: bash

The script doesn't verify if the target directory exists before downloading files. This could cause wget to fail if the directory is missing. Add a mkdir command to ensure the directory exists.
Existing Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
TARGET_DIR="/usr/share/backgrounds/Chicago95/Wallpaper"

mkdir -p "$TARGET_DIR"
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"

Add error handling to downloads

general

File: files/scripts/24-wallpapers.sh | Language: bash

Using 10 parallel wget processes without error handling could overwhelm the server or fail silently. Consider adding wget options for retry and timeout, and check for download failures.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} sh -c 'wget --retry-connrefused --waitretry=1 --read-timeout=20 --timeout=15 -t 3 -P "$1" "$2" || exit 1' -- "$TARGET_DIR" "{}"

Model 11

Handle individual download failures.

general

File: files/scripts/24-wallpapers.sh | Language: bash

The current script uses `set -e`, which will cause the script to exit immediately if any single `wget` command invoked by `xargs` fails. This prevents subsequent wallpapers from being downloaded if one fails. Iterate through the URLs using a loop and handle potential `wget` errors for each URL individually, allowing the script to continue attempting other downloads.
Existing Code
printf "%s\n" "${URLS[@]}" | xargs -n 1 -P 10 -I{} wget -P "$TARGET_DIR" "{}"
Improved Code
for url in "${URLS[@]}"; do
  echo "Downloading: $url"
  wget -P "$TARGET_DIR" "$url" || echo "WARNING: Failed to download $url" >&2
done