Linux 磁盘已满时删除文件的Shell脚本
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原文地址: http://stackoverflow.com/questions/5908919/
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Shell script to delete files when disk is full
提问by Roy
I am writing a small little script to clear space on my linux everyday via CRON if the cache directory grows too large. Since I am really green at bash scripting, I will need a little bit of help from you linux gurus out there.
如果缓存目录变得太大，我正在编写一个小的脚本来每天通过 CRON 清除我的 linux 上的空间。由于我对 bash 脚本编写非常熟悉，因此我需要一些 linux 专家的帮助。
Here is basically the logic (pseudo-code)
这里基本上是逻辑（伪代码）
if ( Drive Space Left < 5GB )
{
change directory to '/home/user/lotsa_cache_files/'
if ( current working directory = '/home/user/lotsa_cache_files/')
{
delete files in /home/user/lotsa_cache_files/
}
}
Getting drive space left
获得剩余驱动器空间
I plan to get the drive space left from the '/dev/sda5' command. If returns the following value to me for your info :
我计划从“/dev/sda5”命令中获得剩余的驱动器空间。如果将以下值返回给我以获取您的信息：
Filesystem 1K-blocks Used Available Use% Mounted on<br>
/dev/sda5 225981844 202987200 11330252 95% /
So a little regex might be necessary to get the '11330252' out of the returned value
因此，可能需要一些正则表达式才能从返回值中获取“11330252”
A little paranoia
有点偏执
The 'if ( current working directory = /home/user/lotsa_cache_files/)' part is just a defensive mechanism for the paranoia within me. I wanna make sure that I am indeed in '/home/user/lotsa_cache_files/' before I proceed with the delete command which is potentially destructive if the current working directory is not present for some reason.
'if ( current working directory = /home/user/lotsa_cache_files/)' 部分只是我内心的偏执的防御机制。在继续执行删除命令之前，我想确保我确实在“/home/user/lotsa_cache_files/”中，如果由于某种原因当前工作目录不存在，该命令可能具有破坏性。
Deleting files
删除文件
The deletion of files will be done with the command below instead of the usual rm -f:
文件的删除将使用下面的命令而不是通常的 rm -f 来完成：
find . -name "*" -print | xargs rm
This is due to the inherent inability of linux systems to 'rm' a directory if it contains too many files, as I have learnt in the past.
这是由于 linux 系统固有的无法“rm”包含太多文件的目录，正如我过去所了解的那样。
采纳答案by hmontoliu
Just another proposal (comments within code):
只是另一个提议（代码中的评论）：
FILESYSTEM=/dev/sda1 # or whatever filesystem to monitor
CAPACITY=95 # delete if FS is over 95% of usage
CACHEDIR=/home/user/lotsa_cache_files/
# Proceed if filesystem capacity is over than the value of CAPACITY (using df POSIX syntax)
# using [ instead of [[ for better error handling.
if [ $(df -P $FILESYSTEM | awk '{ gsub("%",""); capacity = }; END { print capacity }') -gt $CAPACITY ]
then
# lets do some secure removal (if $CACHEDIR is empty or is not a directory find will exit
# with error which is quite safe for missruns.):
find "$CACHEDIR" --maxdepth 1 --type f -exec rm -f {} \;
# remove "maxdepth and type" if you want to do a recursive removal of files and dirs
find "$CACHEDIR" -exec rm -f {} \;
fi
Call the script from crontab to do scheduled cleanings
从 crontab 调用脚本来执行预定的清理
回答by Cédric Julien
To detect the occupation of a filesystem, I use this :
为了检测文件系统的占用，我使用这个：
df -k $FILESYSTEM | tail -1 | awk '{print }'
which give me the occupation percentage of the filesystem, this way, I do not need to compute it :)
这给了我文件系统的占用百分比，这样，我不需要计算它:)
If you use bash, you can use the pushd/popd operation to change directory and be sure to be in.
如果你使用bash，你可以使用pushd/popd操作来改变目录，并且一定要在。
pushd '/home/user/lotsa_cache_files/'
do the stuff
popd
回答by bmk
I would do it this way:
我会这样做：
# get the available space left on the device
size=$(df -k /dev/sda5 | tail -1 | awk '{print }')
# check if the available space is smaller than 5GB (5000000kB)
if (($size<5000000)); then
# find all files under /home/user/lotsa_cache_files and delete them
find /home/user/lotsa_cache_files -name "*" -delete
fi
回答by lfjeff
Here's the script I use to delete old files in a directory to free up space...
这是我用来删除目录中的旧文件以释放空间的脚本...
#!/bin/bash
#
# prune_dir - prune directory by deleting files if we are low on space
#
DIR=
CAPACITY_LIMIT=
if [ "$DIR" == "" ]
then
echo "ERROR: directory not specified"
exit 1
fi
if ! cd $DIR
then
echo "ERROR: unable to chdir to directory '$DIR'"
exit 2
fi
if [ "$CAPACITY_LIMIT" == "" ]
then
CAPACITY_LIMIT=95 # default limit
fi
CAPACITY=$(df -k . | awk '{gsub("%",""); capacity=}; END {print capacity}')
if [ $CAPACITY -gt $CAPACITY_LIMIT ]
then
#
# Get list of files, oldest first.
# Delete the oldest files until
# we are below the limit. Just
# delete regular files, ignore directories.
#
ls -rt | while read FILE
do
if [ -f $FILE ]
then
if rm -f $FILE
then
echo "Deleted $FILE"
CAPACITY=$(df -k . | awk '{gsub("%",""); capacity=}; END {print capacity}')
if [ $CAPACITY -le $CAPACITY_LIMIT ]
then
# we're below the limit, so stop deleting
exit
fi
fi
fi
done
fi
