Linux文件清空的五种方法总结分享_linux清空文件内容

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[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# > test.txt

[root@centos7 ~]# du -h test.txt

0 test.txt

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[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# true > test.txt

[root@centos7 ~]# du -h test.txt

0 test.txt

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[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# cat /dev/null > test.txt

[root@centos7 ~]# du -h test.txt

 test.txt

###################################################

[root@centos7 ~]# echo "Hello World" > test.txt

[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# cp /dev/null test.txt

cp：是否覆盖"test.txt"？ y

[root@centos7 ~]# du -h test.txt

 test.txt

##################################################

[root@centos7 ~]# echo "Hello World" > test.txt

[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# 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

[root@centos7 ~]# du -h test.txt

 test.txt

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[root@centos7 ~]# echo "Hello World" > test.txt

[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# echo -n "" > test.txt ==>要加上"-n"参数，默认情况下会"\n"，也就是回车符

[root@centos7 ~]# du -h test.txt

0 test.txt

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[root@centos7 ~]# du -h test.txt

4.0K test.txt

[root@centos7 ~]# 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；

[root@centos7 ~]# du -h test.txt

0 test.txt