这是我最近为 cron 工作所做的一个半相关的 bash 脚本。它查看存储自动生成的备份的某个目录,如果目录的大小超过用户指定的限制,则删除最旧的备份。同时维护一个 .log 文件。
#!/bin/bash
# IFS is needed for bash to recognize spaces
IFS=$'\n'
# Backup directory
BACKUPDIR="your directory here"
# Backup directory size limit (in kB)
DIRLIMIT=20971520
# Start logging
LOGFILE="where you want the log file stored"
echo -e "Cron job started at $(date +"%m/%d/%Y %r")\r" >> $LOGFILE
echo -e "Directory size limit: $DIRLIMIT [kB]\r" >> $LOGFILE
# If $BACKUPDIR exitsts, find its size
if [ -d "$BACKUPDIR" ]
then
DIRSIZE=$(du -sk "$BACKUPDIR" | awk '{print $1}')
echo -e "Current directory size: $DIRSIZE [kB]\r" >> $LOGFILE
else
echo -e "$BACKUPDIR does not exist!\r" >> $LOGFILE
fi
# Check if $BACKUPDIR's size is greater than $DIRLIMIT. If so, delete
# old files. If not, exit.
if [ $DIRSIZE -gt $DIRLIMIT ]
then
echo -e "Directory size over limit! Attempting to delete oldest log backups...\r" >> $LOGFILE
LOOPSIZE=$DIRSIZE
while [ $LOOPSIZE -gt $DIRLIMIT ]
do
# This find command below finds files (-type f) in the $BACKUPDIR directory only
# (-maxdepth 1) and it prints their last modified time and filename followed by a new line (-printf "%T@ %p\n").
# Then it sorts it based on time (sort -n) and selects the file which was modified the furthest in the past. The
# awk command removes the timestamp (which is in field $1). Finally, xargs -I{} -f {} deletes the file even though spaces are
# present in the full file name.
echo -e "Deleting file: $(find "$BACKUPDIR" -type f -maxdepth 1 -printf "%T@ %f\n" | sort -n | head -1 | awk '{ print substr($0, index($0,$2)) }')\r" >> $LOGFILE
find "$BACKUPDIR" -type f -maxdepth 1 -printf "%T@ %p\n" | sort -n | head -1 | awk '{ print substr($0, index($0,$2)) }' | xargs -I{} rm -f {}
# This function calculates the $BACKUPDIR size again and is used in the loop to see when it is permissable to exit.
LOOPSIZE=$(du -sk "$BACKUPDIR" | awk '{print $1}')
echo -e "Directory size is now: $LOOPSIZE [kB]\r" >> $LOGFILE
done
echo -e "Operation completed successfully! Final directory size is: $LOOPSIZE [kB]\r" >> $LOGFILE
else
echo -e "Directory size is less than limit. Exiting.\r" >> $LOGFILE
fi
# Finish logging
echo -e "\r" >> $LOGFILE
echo -e "Cron job exiting at $(date +"%m/%d/%Y %r")\r" >> $LOGFILE
echo -e "----------------------------------------------------------------------\r" >> $LOGFILE
为了确保 .log 文件永远不会变得令人讨厌,我制作了一个 cron 脚本来修剪最上面的条目:
#!/bin/bash
# IFS is needed for bash to recognize spaces
IFS=$'\n'
# .log files directory
LOGFILESDIR="your directory here"
# .log file size limits (in KB)
LOGFILELIMIT=35
# Find .log files in $LOGFILESDIR and remove the earliest logs if
# the filesize is greater than $LOGFILELIMIT.
for FILE in "$LOGFILESDIR"/*.log
do
LOGSIZE=$(du -sk "$FILE" | awk '{print $1}')
while [ $LOGSIZE -gt $LOGFILELIMIT ]
do
# The sed command deletes the rows from the top
# until it encounters a bunch of "-"'s in a row
# (which separates the logs in the log files)
sed -i '1,/----------/d' "$FILE"
LOGSIZE=$(du -sk "$FILE" | awk '{print $1}')
done
done
exit