Memo a few useful shell scripts

(1) under the shell, operate the Hadoop directory, batch name or delete, the final command sed the regular greedy replacement, look at the following script:

Java code

2. # traverse the file name under the Hadoop directory
6. for line in ' Hadoop fs-ls/user/d1 | Gawk ' {print $8} '
8. Do
12. #echo $line;
16. #将 files in level 2 directory, move to the top level
18. #hadoop fs-mv $line"/tmp_search_keywords_cate_stat/*" $line;
20. #删除 level 2 Directory
22. #hadoop fs-rm-r $line"/tmp_search_keywords_cate_stat"
26. for line2 in ' Hadoop fs-ls $line | Gawk ' {print $8} '
30. Do
34. echo $line 2;
38. #将/tmp/a/b use sed to become/tmp/a_b note the following regular formula
42. Newname= ' echo $line 2 | Sed-e ' s/\ (. *\) \//\1_/' ;
48. #echo $newname;
52. Hadoop FS-MV $line 2 $newname
54. Done
56. Done

# traverse the name of the Hadoop directory for line in ' Hadoop fs-ls/user/d1 | Gawk ' {print $8} ' Do#echo $line;   #将2级目录下的文件, move to the previous level #hadoop FS-MV $line "/tmp_search_keywords_cate_stat/*"  $line; #删除2级目录 #hadoop FS   -rm-r  $line "/tmp_search_keywords_cate_stat" for line2 in ' Hadoop fs-ls $line  | gawk ' {print $8} '   doecho $line 2; #将/tm p/a/b use SED to become/tmp/a_b note the following regular expression newname= ' echo $line 2 | Sed-e ' s/\ (. *\) \//\1_/'; #echo $newname; Hadoop fs-mv $line 2   $newnamedonedone

(2) record the currently started process ID and suspend the operation in the background, the script example is as follows:

Java code

1. [Search@fse4 solr]$ cat start.sh
3. #下面的代码, record the last initiated process ID that is currently started
4. #方便关闭时, kill.
6. #$$ records the current process id,$! records the process ID that was last started
7. #nohup is the background hangs the thread way to run, and the log file output to nohup.out inside, carries on the monitoring
8. Nohup Java-jar start.jar &> nohup.out & Echo $! >pid&
10. #echo $$ > PID
11. [Search@fse4 solr]$

[[email protected] solr]$ cat start.sh #下面的代码, log down the process ID of the last boot that is currently started # when it is convenient to close, kill #$$ record the current process id,$! record the process that was last started Id#nohup Is the background hangs thread mode run, and the log file output to nohup.out inside, to monitor nohup Java-jar start.jar  &> nohup.out &  

(3) Under Linux, the string date is formatted as a timestamp:

Java code

1. [Search@fsedump01sand tempshell]$ date-d ' 2015-12-01 ' +%s
2. 1448899200

Memo a few useful shell scripts