hdfs常用操作命令
在master上以hadoop-twq用户登录
cd ~、ls /
查看hdfs文件目录:
hadoop fs -ls hdfs://master:9999/(当前还没有文件)
效果等同于:hadoop fs -ls /
效果也等同于:hdfs dfs -ls /
在这个根目录创建一个文件或目录:
hadoop fs -mkdir /user
效果等同于:hadoop fs -mkdir hdfs://master:9999/user
在webui上刷新可以看到多了一个user目录
再创建一个目录:hadoop fs -mkdir /user/hadoop-twq/cmd(会报错)
正确的方式:hadoop fs -mkdir -p /user/hadoop-twq/cmd(递归创建)
把本地文件word.txt上传到hdfs文件系统上去:
hadoop fs -copyfromlocal word.txt /user/hadoop-twq/cmd
查看:hadoop fs -ls /user/hadoop-twq/cmd(txt文件存在)
再上传一次就会报错,如果想要覆盖文件要加-f
hadoop fs -copyfromlocal -f word.txt /user/hadoop-twq/cmd
查看文件内容:
hadoop fs -cat /user/hadoop-twq/cmd/word.txt
用put方式代替copyfromlocal方式上传:
hadoop fs -put -f word.txt /user/hadoop-twq/cmd
将两个文件一起上传:
hadoop fs -put test.sh word2.txt /user/hadoop-twq/cmd
put还可以将文件流写到hdfs中:
hadoop fs -put - /user/hadoop-twq/cmd/put.txt(回车输入内容,ctrl+d结束输入)然后查看
下载put.txt:
hadoop fs -get /user/hadoop-twq/cmd/put.txt
创建文件:
hadoop fs -touchz /user/hadoop-twq/cmd/flag.txt
将flag.txt移动到/user/hadoop-twq目录下:
hadoop fs -mv /user/hadoop-twq/cmd/flag.txt /user/hadoop-twq
将put.txt文件权限改成744:
hadoop fs -chmod 744 /user/hadoop-twq/cmd/put.txt
将cmd目录权限改成777:
hadoop fs -chmod -r 777 /user/hadoop-twq/cmd
查看big_file.txt文件大小:
ll -h(发现是153m)
把big_file.txt上传到hdfs文件系统中:
hadoop fs -put big_file.txt /user/hadoop-twq/cmd
尝试列出文件命令的异同:
hadoop fs -ls /user/hadoop-twq/cmd
hadoop fs -ls -h /user/hadoop-twq/cmd
hadoop fs -ls -d /user/hadoop-twq/cmd
hadoop fs -ls -r /user/hadoop-twq/cmd
hadoop fs -ls -r /user/hadoop-twq
hadoop fs -ls -r /user
查看文件大小:
hadoop fs -du /user/hadoop-twq/cmd
hadoop fs -du -h /user/hadoop-twq/cmd(大小可读)
hadoop fs -du -s -h /user/hadoop-twq/cmd(整个目录有多大)
查看hdfs总共有多大:
hadoop fs -df
hadoop fs -df -h(大小可读)
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