compress-large-files

name	compress-large-files
description	Compress large files and directories in ~/Desktop/MAIN/kalvin/testcase_and_creds to save disk space. Gzips logcat .txt files, tarballs raw Firebase result folders, and reports space saved. Use when user asks to compress test results, clean up testcase_and_creds, or free up disk space.
tools	Bash

Compress Large Files — testcase_and_creds

Target directory: ~/Desktop/MAIN/kalvin/testcase_and_creds/

What gets compressed

Type	Pattern	Action
Logcat text files	logcat_v*.txt, v*_logcat.txt, logcat_v* (no ext)	gzip in place → .gz
Raw Firebase result folders	20*_firebase*/, 20*_*/ (dated dirs)	tar czf <name>.tar.gz <dir> && rm -rf <dir>
Screenshot PNGs	*.png (>1 MB)	gzip in place → .png.gz

What is NOT touched

• service-account-key.json — credentials, never compress or move
• logcat_v*.gz / *.tar.gz — already compressed
• The most recent logcat (latest by modification time) — keep it readable for active debugging

Workflow

Step 1 — Show current state

du -sh ~/Desktop/MAIN/kalvin/testcase_and_creds/test-results/* | sort -rh | head -20
du -sh ~/Desktop/MAIN/kalvin/testcase_and_creds/

Step 2 — Compress logcat text files (skip most recent)

RESULTS="$HOME/Desktop/MAIN/kalvin/testcase_and_creds/test-results"

# Find all uncompressed logcats, skip the newest one
LOGCATS=$(find "$RESULTS" -maxdepth 1 \( -name "logcat_v*.txt" -o -name "*_logcat.txt" \) | sort)
NEWEST=$(echo "$LOGCATS" | tail -1)

for f in $LOGCATS; do
  if [ "$f" = "$NEWEST" ]; then
    echo "Skipping newest: $f"
    continue
  fi
  gzip "$f" && echo "Compressed: $f → $f.gz"
done

# Compress logcats without extension
for f in "$RESULTS"/logcat_v*; do
  [ -f "$f" ] && [[ "$f" != *.gz ]] && [[ "$f" != *.txt ]] && \
    gzip "$f" && echo "Compressed: $f → $f.gz"
done

Step 3 — Tar raw Firebase result folders

RESULTS="$HOME/Desktop/MAIN/kalvin/testcase_and_creds/test-results"
cd "$RESULTS"

for dir in 20*; do
  [ -d "$dir" ] && \
    tar czf "${dir}.tar.gz" "$dir" && \
    rm -rf "$dir" && \
    echo "Archived: $dir → ${dir}.tar.gz"
done

Step 4 — Compress large PNGs (>1MB, skip thumbnails)

RESULTS="$HOME/Desktop/MAIN/kalvin/testcase_and_creds/test-results"
find "$RESULTS" -maxdepth 1 -name "*.png" -size +1M -exec gzip {} \; -print

Step 5 — Report savings

echo "=== After compression ==="
du -sh ~/Desktop/MAIN/kalvin/testcase_and_creds/test-results/
du -sh ~/Desktop/MAIN/kalvin/testcase_and_creds/

Split large files for distribution (e.g. GitHub upload)

Split into 99 MB chunks

split -b 99m app.apk app.part-
# Produces: app.part-aa, app.part-ab, app.part-ac ...

Combine parts back

cat app.part-* > app_restored.apk

Verify integrity

# Before splitting — generate checksum
shasum -a 256 app.apk > app.apk.sha256

# After combining — verify
shasum -a 256 -c app.apk.sha256
# Expected: app.apk: OK

Verify APK is a valid ZIP

unzip -t app_restored.apk
# Should end with: No errors detected in compressed data

Note: Never gzip .apk files — APKs are already ZIP-compressed; gzip makes them larger. Always store the .sha256 alongside the parts for later verification.

---

Decompressing when needed

# Single logcat
gunzip ~/Desktop/MAIN/kalvin/testcase_and_creds/test-results/logcat_v25.txt.gz

# Firebase result folder
cd ~/Desktop/MAIN/kalvin/testcase_and_creds/test-results
tar xzf 2026-02-27_firebase.tar.gz

# All logcats
gunzip ~/Desktop/MAIN/kalvin/testcase_and_creds/test-results/logcat_v*.gz

Expected savings

Logcat .txt files compress ~80% with gzip (text with repeating patterns). Firebase result folders (video, screenshots, XML) compress ~30-50%. Total expected: 5-6 GB → ~1.5-2 GB.