执行语句如下：
bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.2.jar grep input output 'dfs[a-z.]+'报错如下：
21/06/29 15:44:52 WARN mapred.LocalJobRunner: job_local270656271_0001
java.lang.Exception: java.io.IOException: Mkdirs failed to create file:/opt/module/hadoop-2.7.2/grep-temp-1270589453/_temporary/0/_temporary/attempt_local270656271_0001_r_000000_0 (exists=false, cwd=file:/opt/module/hadoop-2.7.2)
at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:529)
Caused by: java.io.IOException: Mkdirs failed to create file:/opt/module/hadoop-2.7.2/grep-temp-1270589453/_temporary/0/_temporary/attempt_local270656271_0001_r_000000_0 (exists=false, cwd=file:/opt/module/hadoop-2.7.2)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:449)
at org.apache.hadoop.fs.ChecksumFileSystem.create(ChecksumFileSystem.java:435)
at org.apache.hadoop.fs.FileSystem.create(FileSystem.java:909)
at org.apache.hadoop.io.SequenceFile$Writer.<init>(SequenceFile.java:1134)
at org.apache.hadoop.io.SequenceFile.createWriter(SequenceFile.java:273)
at org.apache.hadoop.io.SequenceFile.createWriter(SequenceFile.java:530)
at org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat.getSequenceWriter(SequenceFileOutputFormat.java:64)
at org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat.getRecordWriter(SequenceFileOutputFormat.java:75)
at org.apache.hadoop.mapred.ReduceTask$NewTrackingRecordWriter.<init>(ReduceTask.java:540)
at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:614)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:389)
at org.apache.hadoop.mapred.LocalJobRunner$Job$ReduceTaskRunnable.run(LocalJobRunner.java:319)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
21/06/29 15:44:53 INFO mapreduce.Job: Job job_local270656271_0001 failed with state FAILED due to: NA
21/06/29 15:44:53 INFO mapreduce.Job: Counters: 30
File System Counters
FILE: Number of bytes read=2387501
FILE: Number of bytes written=4422808
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
Map-Reduce Framework
Map input records=745
Map output records=1
Map output bytes=17
Map output materialized bytes=67
Input split bytes=925
Combine input records=1
Combine output records=1
Reduce input groups=0
Reduce shuffle bytes=67
Reduce input records=0
Reduce output records=0
Spilled Records=1
Shuffled Maps =8
Failed Shuffles=0
Merged Map outputs=8
GC time elapsed (ms)=105
Total committed heap usage (bytes)=2818887680
Shuffle Errors
BAD_ID=0
CONNECTION=0
IO_ERROR=0
WRONG_LENGTH=0
WRONG_MAP=0
WRONG_REDUCE=0
File Input Format Counters
Bytes Read=26007
File Output Format Counters
Bytes Written=0
21/06/29 15:44:53 INFO jvm.JvmMetrics: Cannot initialize JVM Metrics with processName=JobTracker, sessionId= - already initialized
21/06/29 15:44:53 INFO mapreduce.JobSubmitter: Cleaning up the staging area file:/tmp/hadoop-wll/mapred/staging/wll730934781/.staging/job_local730934781_0002
org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exist: file:/opt/module/hadoop-2.7.2/grep-temp-1270589453
at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:323)
at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.listStatus(FileInputFormat.java:265)
at org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat.listStatus(SequenceFileInputFormat.java:59)
at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.getSplits(FileInputFormat.java:387)
at org.apache.hadoop.mapreduce.JobSubmitter.writeNewSplits(JobSubmitter.java:301)
at org.apache.hadoop.mapreduce.JobSubmitter.writeSplits(JobSubmitter.java:318)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:196)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1290)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1287)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1287)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1308)
at org.apache.hadoop.examples.Grep.run(Grep.java:94)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.hadoop.examples.Grep.main(Grep.java:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:71)
at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:74)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.util.RunJar.run(RunJar.java:221)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)网上搜了好多，都是报错“未知的名称或服务 ”，和我的错误不一样，看报错日志好像是jvm初始化的问题，但具体怎么解决不太会，大家有没有知道的
不了解Hadoop，不过看错误是创建文件夹失败，最好检查下权限问题
输入目录自己创建，输出目录一般要先删除，执行程序时会自动创建