Stop Googling the
Same Bash Commands

#!/bin/bash
# Copies a folder to /backup with today's timestamp.
# Run manually or schedule with cron — works either way.

SOURCE="/home/user/documents"
DEST="/backup"
DATE=$(date +%Y-%m-%d_%H-%M)

mkdir -p "$DEST"
cp -r "$SOURCE" "$DEST/backup_$DATE"
echo "Done. Saved to: backup_$DATE"

#!/bin/bash
# Renames every .txt file to .md — useful after
# exporting notes, docs, or data dumps.

for file in *.txt; do
  [ -f "$file" ] || continue
  newname="${file%.txt}.md"
  mv "$file" "$newname"
  echo "Renamed: $file → $newname"
done

#!/bin/bash
# Checks disk usage and warns if over 80%.
# Great for daily cron on a server or VPS.

THRESHOLD=80
USAGE=$(df / | awk 'NR==2{print $5}' | tr -d '%')

if [ "$USAGE" -gt "$THRESHOLD" ]; then
  echo "⚠ Disk at ${USAGE}% — time to clean up"
else
  echo "✓ Disk OK: ${USAGE}% used"
fi

#!/bin/bash
# Deletes .log files older than 30 days.
# Replace -delete with -print to preview first!

LOG_DIR="/var/log/myapp"
DAYS=30

find "$LOG_DIR" -type f -name "*.log" \
  -mtime +$DAYS -delete

echo "Cleaned logs older than $DAYS days"

#!/bin/bash
# Prints key stats at a glance. Alias to 'syscheck'
# in your .bashrc for fast access.

echo "=== Quick System Check ==="
echo "Host    : $(hostname)"
echo "Uptime  : $(uptime -p)"
echo "RAM     : $(free -h | awk '/Mem/{print $3"/"$2}')"
echo "Disk /  : $(df -h / | awk 'NR==2{print $3"/"$2}')"
echo "IP      : $(hostname -I | awk '{print $1}')"
echo "========================="

#!/bin/bash
# Creates a folder named with today's date in ~/work.
# I run this as my very first command every morning.

BASE="$HOME/work"
TODAY=$(date +%Y-%m-%d)
DIR="$BASE/$TODAY"

mkdir -p "$DIR"
echo "Ready. Working in: $DIR"
# xdg-open "$DIR"  # uncomment to open in file manager

#!/bin/bash
# Pings a URL and reports if it's reachable.
# Use with cron to alert you when a site goes down.

URL="https://example.com"
STATUS=$(curl -o /dev/null -s -w "%{http_code}" "$URL")

if [ "$STATUS" -eq 200 ]; then
  echo "✓ $URL is up (HTTP $STATUS)"
else
  echo "✗ $URL returned HTTP $STATUS — check it"
fi

#!/bin/bash
# Searches all .txt files in a folder for a keyword.
# Shows filename and line number for each match.

SEARCH_DIR="$HOME/documents"
KEYWORD="TODO"

echo "Searching for '$KEYWORD'..."
grep -rn "$KEYWORD" "$SEARCH_DIR" --include="*.txt"
echo "Done."

#!/bin/bash
# Counts total lines across all .py files in a project.
# Quick LOC estimate without installing any extra tools.

PROJECT_DIR="$HOME/myproject"
EXT="py"

TOTAL=$(find "$PROJECT_DIR" -name "*.$EXT" \
  | xargs wc -l 2>/dev/null \
  | tail -1 | awk '{print $1}')

echo "Total lines of .$EXT code: $TOTAL"

#!/bin/bash
# Finds files with identical content using MD5 hashes.
# Run on Downloads folder to surface duplicates.

TARGET="$HOME/Downloads"

echo "Scanning for duplicates in $TARGET..."
find "$TARGET" -type f \
  | xargs md5sum 2>/dev/null \
  | sort \
  | awk 'seen[$1]++'

#!/bin/bash
# Compresses a folder into a dated .tar.gz archive.
# Smaller than .zip and native to every Linux system.

SOURCE="/home/user/project"
OUTPUT="/backup/project_$(date +%Y%m%d).tar.gz"

tar -czf "$OUTPUT" -C "$(dirname $SOURCE)" \
    "$(basename $SOURCE)"

echo "Archive created: $OUTPUT"
ls -lh "$OUTPUT"

#!/bin/bash
# Safe bash template — use this as your starting point
# for any script you actually care about.

set -euo pipefail  # exit on error, unset vars, pipe fails
IFS=$'\n\t'        # safer word splitting

# Your code starts here
echo "Script started at $(date)"

# ... add your logic ...

echo "Script completed successfully"