需求：编写Shell脚本实现指定目录tar.gz压缩并按日期命名复制

Got it, let's build a reliable shell script that handles your full backup and timestamped compression needs perfectly. Here's a complete solution tailored to your requirements:

First, here's the full script you can use. Save it as something like ndb_backup.sh and make it executable with chmod +x ndb_backup.sh:

#!/bin/bash

# Define source and target directories
SOURCE_DIR="/hana/shared/backup_service/backups/30015/NDB/"
TARGET_DIR="/hana/data/"

# Create target directory if it doesn't exist
mkdir -p "$TARGET_DIR"

# Generate timestamp in YYYYMMDDHHMMSS format
TIMESTAMP=$(date +%Y%m%d%H%M%S)
TAR_FILE="${TARGET_DIR}bck_${TIMESTAMP}.tar.gz"

# Perform full backup and compression
echo "Starting full backup of $SOURCE_DIR to $TAR_FILE..."
if tar -czf "$TAR_FILE" -C "$SOURCE_DIR" .; then
    echo "Backup completed successfully! File saved to: $TAR_FILE"
else
    echo "ERROR: Backup failed!" >&2
    exit 1
fi

Let's break down what each part does: #

• Directory Definitions: SOURCE_DIR points to the folder you want to back up (note the trailing / to ensure we capture all contents inside, not the folder itself). TARGET_DIR is where the compressed backup will live.
• Target Directory Check: mkdir -p ensures the target directory exists—if it doesn't, it creates it (and any parent folders needed) without throwing errors.
• Timestamp Generation: date +%Y%m%d%H%M%S creates a unique timestamp (year, month, day, hour, minute, second) so every backup has a distinct filename, just like your examples (bck_20180121000002).
• Tar Command:
  • -czf: Creates (c) a gzip-compressed (z) archive and specifies the output file (f).
  • -C "$SOURCE_DIR" .: Changes to the source directory first, then archives everything in it (.), which ensures we get all contents of the NDB folder without including the folder itself in the archive.
• Error Handling: The if statement checks if the tar command succeeded. If it did, it prints a success message; if not, it outputs an error and exits with a non-zero code (useful for monitoring or cron jobs).

Extra Tips for Production Use: #

• Permissions: Make sure the user running this script has read access to $SOURCE_DIR and write access to $TARGET_DIR.
• Cron Job: To automate backups, add this script to your crontab. For example, to run it daily at midnight, add:

  0 0 * * * /path/to/ndb_backup.sh >> /var/log/ndb_backup.log 2>&1
  

  This also logs all output to a log file for debugging.
• Clean Up Old Backups: If you don't need to keep backups forever, add a line to delete backups older than X days. For example, to delete backups older than 30 days:

  find "$TARGET_DIR" -name "bck_*.tar.gz" -mtime +30 -delete
  

内容的提问来源于stack exchange，提问作者Momar