将linux文件清空
程序员文章站
2024-02-11 14:02:52
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1、使用重定向的方法
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# > test.txt
[[email protected] ~]# du -h test.txt
0 test.txt
2、使用true命令重定向清空文件
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# true > test.txt
[[email protected] ~]# du -h test.txt
0 test.txt
3、使用cat/cp/dd命令及/dev/null设备来清空文件
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# cat /dev/null > test.txt
[[email protected] ~]# du -h test.txt
0 test.txt
###################################################
[[email protected] ~]# echo "Hello World" > test.txt
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# cp /dev/null test.txt
cp：是否覆盖"test.txt"？ y
[[email protected] ~]# du -h test.txt
0 test.txt
##################################################
[[email protected] ~]# echo "Hello World" > test.txt
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# dd if=/dev/null of=test.txt
记录了0+0 的读入
记录了0+0 的写出
0字节(0 B)已复制，0.000266781 秒，0.0 kB/秒
[[email protected] ~]# du -h test.txt
0 test.txt
4、使用echo命令清空文件
[[email protected] ~]# echo "Hello World" > test.txt
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# echo -n "" > test.txt ==>要加上"-n"参数，默认情况下会"\n"，也就是回车符
[[email protected] ~]# du -h test.txt
0 test.txt
5、使用truncate命令清空文件
[[email protected] ~]# du -h test.txt
4.0K test.txt
[[email protected] ~]# truncate -s 0 test.txt -s参数用来设定文件的大小，清空文件，就设定为0；
[[email protected] ~]# du -h test.txt
0 test.txt