|   | 17 |  * 首先,我們想要瞭解上述練習中一直使用到的指令 hadoop 是什麼。讓我們先用 which 指令,找出它所在的路徑 | 
                  
                          |   | 18 | {{{ | 
                  
                          |   | 19 | user@node1:~/hadoop_labs$ which hadoop | 
                  
                          |   | 20 | /home/user/hadoop/bin/hadoop  | 
                  
                          |   | 21 | }}} | 
                  
                          |   | 22 |  | 
                  
                          |   | 23 |  * 接著,讓我們用指令 file 來查出這個 hadoop 指令是什麼格式。 | 
                  
                          |   | 24 | {{{ | 
                  
                          |   | 25 | user@node50:~/hadoop_labs$ file `which hadoop` | 
                  
                          |   | 26 | /home/user/hadoop/bin/hadoop: a bash script, ASCII text executable  | 
                  
                          |   | 27 | }}} | 
                  
                          |   | 28 |  | 
                  
                          |   | 29 |  * 現在我們知道它是 bash script,那如何針對 bash script 進行除錯呢?我們可以用 bash -x 參數來進行除錯! | 
                  
                          |   | 30 | {{{ | 
                  
                          |   | 31 | user@node50:~/hadoop_labs$ bash -x `which hadoop` fs -ls  | 
                  
                          |   | 32 | .... 略 .... | 
                  
                          |   | 33 | adoop/libexec/../lib/slf4j-api-1.4.3.jar:/home/user/hadoop/libexec/../lib/slf4j-log4j12-1.4.3.jar:/home/user/hadoop/libex | 
                  
                          |   | 34 | ec/../lib/xmlenc-0.52.jar:/home/user/hadoop/libexec/../lib/jsp-2.1/jsp-2.1.jar:/home/user/hadoop/libexec/../lib/jsp-2.1/j | 
                  
                          |   | 35 | sp-api-2.1.jar org.apache.hadoop.fs.FsShell -ls | 
                  
                          |   | 36 | Found 3 items | 
                  
                          |   | 37 | drwxr-xr-x - user supergroup 0 2013-09-23 00:28 /user/user/input | 
                  
                          |   | 38 | drwxr-xr-x - user supergroup 0 2013-09-23 00:27 /user/user/tmp | 
                  
                          |   | 39 | drwxr-xr-x - user supergroup 0 2013-09-23 00:34 /user/user/toHDFS  | 
                  
                          |   | 40 | }}} | 
                  
                          |   | 41 |  |