java executing linux command

Question

I`m trying to execute linux commant 'cat' from java code, but it does not working.

Runtime.getRuntime().exec("cat /home/roman/logs/*");

And it working well for cat of single file

Runtime.getRuntime().exec("cat /home/roman/logs/mylog.log");

My question is how to cat all files on some dir from java ?

possible duplicate of [Want to invoke a linux shell command from Java](http://stackoverflow.com/questions/1410741/want-to-invoke-a-linux-shell-command-from-java) — MK., Apr 03 '12 at 13:05

score 4 · Accepted Answer · answered Apr 03 '12 at 13:09

4

You could put all files under the dir into a collection and iterate over it:

File[] files = dir.listFiles();
for (File f : files) {
  Runtime.getRuntime().exec("cat "+dir.getAbsolutePath()+File.separator+f.getName());
}

answered Apr 03 '12 at 13:09

Yuval

7,987
12
40
54

score 3 · Answer 2 · answered Apr 03 '12 at 13:07

3

You can't use * with the exec() command (you would need a shell). A solution could be to write a script and then exec() that script from your java application.

answered Apr 03 '12 at 13:07

talnicolas

13,885
7
36
56

score 2 · Answer 3 · edited May 23 '17 at 12:20

2

Runtim.exec() does not use a shell to execute the command. Therefore the wildcard is not expanded. Try the solution explained in Want to invoke a linux shell command from java

edited May 23 '17 at 12:20

Community

1
1

answered Apr 03 '12 at 13:10

user1225148

116
2

java executing linux command

3 Answers3

Linked