测试程序java

    static void fileout() throws IOException, InterruptedException {
        FileOutputStream fileOutputStream = new FileOutputStream("/tmp/a.out");
        for(int i = 0;i<1000;i++){
            fileOutputStream.write((System.currentTimeMillis()+"").getBytes(StandardCharsets.UTF_8));
            Thread.sleep(500);
        }
        fileOutputStream.close();
    }

清空测试

yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out 
yeqiang@yeqiang-PC:~$ cat /dev/null > /tmp/a.out

tail效果

yeqiang@yeqiang-PC:~$ tail -f /tmp/a.out 
1642727380983164272738148316427273819831642727382483164272738298416427273834841642727383984164272738448416427273849841642727385484164272738598416427273864851642727386985164272738748516427273879851642727388485164272738898516427273894851642727389985164272739048616427273909861642727391486164272739198616427273924861642727392986164272739348716427273939871642727394487164272739498716427273954871642727395987164272739648716427273969871642727397488164272739798816427273984881642727398988164272739948816427273999881642727400488tail: /tmp/a.out：文件已截断
16427274009891642727401489164272740198916427274024891642727402989164272740348916427274039891642727404489164272740499016427274054901642727405990164272740649016427274069901642727407490164272740799016427274084901642727408991164272740949116427274099911642727410491164272741099116427274114911642727411992tail: /tmp/a.out：文件已截断
1642727412492164272741299216427274134921642727413992tail: /tmp/a.out：文件已截断
1642727414492tail: /tmp/a.out：文件已截断
1642727414993tail: /tmp/a.out：文件已截断
164272741549316427274159931642727416493tail: /tmp/a.out：文件已截断
1642727416993tail: /tmp/a.out：文件已截断
1642727417493tail: /tmp/a.out：文件已截断
1642727417993tail: /tmp/a.out：文件已截断
1642727418493tail: /tmp/a.out：文件已截断
1642727418993tail: /tmp/a.out：文件已截断
1642727419494tail: /tmp/a.out：文件已截断
1642727419994tail: /tmp/a.out：文件已截断
1642727420494164272742099416427274214941642727421994