在 MacOS 上從 cron 執行 bash 腳本時未定義變數（本地定義）

我有以下用於創建備份的腳本：

#!/usr/bin/env bash
{
 declare -a directories=(
   "/Applications/Apache"
   "/Applications/Scripts"
 )

 function duplicateBackups()
 {
   from=`realpath $1`
   to=`realpath $2`
   echo [ `date +"%T"` ] Copying backups from $from to $to
   cp -r $1 $2/
   sleep 1
 }

 date=`date +"%Y-%m-%d"`

 destination1='/opt/Volumes/USB1'
 destination2='/opt/Volumes/USB2'
 destination3='/opt/Volumes/FireWire'
 destination4='/opt/Volumes/USB3'
 destinationFolder='MacMini-Backups'
 targetFolder=$destination1/$destinationFolder/$date

 mkdir $targetFolder
 targetPath=`realpath $targetFolder`

 echo [ `date +"%T"` ] Starting files backups

 for i in "${directories[@]}"
 do
   fileName="$(basename $i)"
   mkdir -p $targetFolder/Files/
   echo [ `date +"%T"` ] Backing up "$i" as "$targetPath/Files/$fileName.tgz"
   tar -Pczf $targetFolder/Files/$fileName.tgz -C $i .
   sleep 1
 done
 echo [ `date +"%T"` ] Files backups finished
 sleep 1
 echo [ `date +"%T"` ] Starting databases backup
 sleep 1

 mkdir -p $targetFolder/Databases/

 echo [ `date +"%T"` ] Backing up all databases into $targetPath/Databases/full-dump.sql.gz
 mysqldump --opt --all-databases --skip-lock-tables | gzip -c > $targetFolder/Databases/full-dump.sql.gz

 for db in `mysql -se "show databases;"`;
 do
   if [[ ${db} != *"schema"* ]]; then
     echo [ `date +"%T"` ] Backing up database $db into $targetPath/Databases/$db-dump.sql.gz
     mysqldump --skip-lock-tables --opt $db | gzip -c > $targetFolder/Databases/$db-dump.sql.gz
     sleep 1
   fi
 done;
 echo [ `date +"%T"` ] Databases backup finished
 sleep 1

 duplicateBackups $destination1/$destinationFolder/$date $destination2/$destinationFolder
 duplicateBackups $destination1/$destinationFolder/$date $destination3/$destinationFolder
 duplicateBackups $destination1/$destinationFolder/$date $destination4/$destinationFolder

} >> /Applications/Scripts/Logs/backups.log

當我手動執行這個腳本時，它工作得非常好，無論是來自 shell、bash 還是 ZSH。

在這種情況下，日誌文件如下所示：

[ 09:26:05 ] Starting files backups
[ 09:26:05 ] Backing up /Applications/Apache as /Volumes/USB1/MacMini-Backups/2020-12-31/Files/Apache.tgz
[ 09:27:14 ] Backing up /Applications/Scripts as /Volumes/USB1/MacMini-Backups/2020-12-31/Files/Scripts.tgz
[ 09:27:15 ] Files backups finished
[ 09:27:16 ] Starting databases backup
[ 09:27:17 ] Backing up all databases into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/full-dump.sql.gz
[ 09:27:35 ] Backing up database Cloud into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/Cloud-dump.sql.gz
[ 09:27:36 ] Backing up database mysql into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/mysql-dump.sql.gz
[ 09:27:38 ] Backing up database radek into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/site-dump.sql.gz
[ 09:27:41 ] Backing up database radek_j3 into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/site_j3-dump.sql.gz
[ 09:27:45 ] Backing up database test into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/test-dump.sql.gz
[ 09:27:46 ] Backing up database site_j3 into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/joomla_3-dump.sql.gz
[ 09:27:48 ] Backing up database joomla_dev into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/joomla_dev-dump.sql.gz
[ 09:27:49 ] Backing up database joomla_dev2 into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/joomla_dev2-dump.sql.gz
[ 09:27:51 ] Backing up database joomla_j4 into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/joomla_j4-dump.sql.gz
[ 09:27:53 ] Backing up database joomla_site into /Volumes/USB1/MacMini-Backups/2020-12-31/Databases/joomla_site-dump.sql.gz
[ 09:28:06 ] Databases backup finished
[ 09:28:07 ] Copying backups from /Volumes/USB1/MacMini-Backups/2020-12-31 to /Volumes/USB2/MacMini-Backups
[ 09:28:30 ] Copying backups from /Volumes/USB1/MacMini-Backups/2020-12-31 to /Volumes/FireWire/MacMini-Backups
[ 09:28:43 ] Copying backups from /Volumes/USB1/MacMini-Backups/2020-12-31 to /Volumes/USB3/MacMini-Backups

但是，如果我通過 cronjob、Automator 甚至 Apple Calendar 執行它，日誌文件看起來像這樣：

[ 06:00:00 ] Starting files backups
[ 06:00:00 ] Backing up /Applications/Apache as /Files/Apache.tgz
[ 06:01:22 ] Backing up /Applications/Scripts as /Files/Scripts.tgz
[ 06:01:23 ] Files backups finished
[ 06:01:25 ] Starting databases backup
[ 06:01:26 ] Backing up all databases into /Databases/full-dump.sql.gz
[ 06:01:26 ] Databases backup finished
[ 06:01:27 ] Copying backups from to
[ 06:01:46 ] Copying backups from to
[ 06:01:58 ] Copying backups from to

我假設我在該腳本中定義的這些變數沒有任何效果。

有誰知道這裡可能是什麼問題？

非常感謝bitinerant和Mark Wagner的幫助。在我添加錯誤輸出後，結果發現它是缺少路徑和缺乏訪問目錄和從 MySQL 讀取數據庫列表的權限之間的混合。

非常感謝

引用自：https://serverfault.com/questions/1049094