日度归档：2018年4月22日

while read line无法读取最后一行的问题

while read line读取文件时，如果文件最后一行之后没有换行符\n,则read读取最后一行时遇到文件结束符EOF,循环终止,虽然此时$line内存有最后一行,但程序已经没有机会再处理此行,因此可以通过以下代码来解决此问题:

while read line || [[ -n ${line} ]]; do
…
done
这样当文件没有结束时不会测试-n $line,当遇到文件结束时,仍然可以通过测试$line是否有内容来进行继续处理。

http://ju.outofmemory.cn/entry/86710

MySQL自动备份到亚马逊S3


#!/bin/sh

# Updates etc at: https://github.com/woxxy/MySQL-backup-to-Amazon-S3
# Under a MIT license

# change these variables to what you need
MYSQLROOT=XXX
MYSQLPASS=XXXX
S3BUCKET=xx-mysql-backup
# DATABASE='--all-databases'
DATABASE=${1-default}
FILENAME=${DATABASE}
HOST=master
DUMPOPTION='--quick --single-transaction'
# the following line prefixes the backups with the defined directory. it must be blank or end with a /
S3PATH=mysql-backup/${DATABASE}
# when running via cron, the PATHs MIGHT be different. If you have a custom/manual MYSQL install, you should set this manually like MYSQLDUMPPATH=/usr/local/mysql/bin/
MYSQLDUMPPATH=
#tmp path.
TMP_PATH=/tmp/

DATESTAMP=$(date +".%Y-%m-%d.%H:%M:%S")
DELDATESTAMP=$(date -d"15 day ago 2017-04-16" +".%Y-%m-%d.%H:%M:%S")
DAY=$(date +"%d")
DAYOFWEEK=$(date +"%A")

PERIOD=${2-day}
if [ ${PERIOD} = "auto" ]; then
if [ ${DAY} = "01" ]; then
PERIOD=month
elif [ ${DAYOFWEEK} = "Sunday" ]; then
PERIOD=week
else
PERIOD=day
fi
fi

echo "Selected period: $PERIOD."

echo "Starting backing up the database to a .gz file..."

# dump all databases
${MYSQLDUMPPATH}mysqldump -h${HOST} ${DUMPOPTION} --user=${MYSQLROOT} --password=${MYSQLPASS} ${DATABASE} | gzip > ${TMP_PATH}${FILENAME}.gz

echo "Done backing up the database to a file."
# echo "Starting compression..."

# tar czf ${TMP_PATH}${FILENAME}${DATESTAMP}.tar.gz ${TMP_PATH}${FILENAME}.sql
mv ${TMP_PATH}${FILENAME}.gz ${TMP_PATH}${FILENAME}${DATESTAMP}.gz

# echo "Done compressing the backup file."

# upload all databases
echo "Uploading the new backup..."
s3cmd put -f --check-md5 -s --continue-put ${TMP_PATH}${FILENAME}${DATESTAMP}.gz s3://${S3BUCKET}/${S3PATH}${PERIOD}/
echo "New backup uploaded."
if [ $? -ne 0 ]
then
echo "Re uploading the backup file..."
s3cmd put -f --check-md5 -s --continue-put ${TMP_PATH}${FILENAME}${DATESTAMP}.gz s3://${S3BUCKET}/${S3PATH}${PERIOD}/
echo "Re upload backup file done."
fi

echo "Moving the backup from past $PERIOD to another folder..."
s3cmd mv --recursive s3://${S3BUCKET}/${S3PATH}${PERIOD}/${FILENAME}${DELDATESTAMP} s3://${S3BUCKET}/${S3PATH}previous_${PERIOD}/
echo "Past backup moved."

# we want at least two backups, two months, two weeks, and two days
echo "Removing old backup (15 ${PERIOD}s ago)..."
s3cmd del --recursive s3://${S3BUCKET}/${S3PATH}previous_${PERIOD}/
echo "Old backup removed."

# remove databases dump
# rm ${TMP_PATH}${FILENAME}.sql
echo "Removing the gz files..."
rm ${TMP_PATH}${FILENAME}${DATESTAMP}.gz
echo "Files removed."
echo "All done."