如何在Linux中通过Java执行Shell脚本并保存为文本文件命令

Question

I m using Linux.

I want to call a small executable application from my java command line which is called "wmic". It needs an input query. Output are stored in text file in the specific directory.

When I use the command in Linux Terminal

echo "Hello World" >> /home/kannan/hello.txt

the output is stored in hello.txt file.

but when i call this command from java

Process p = Runtime.getRuntime().exec("echo \"Hello World\" >> /home/kannan/hello1.txt");

the output is not created any hello1.txt file

Please any one help me.

Thanks in Advance.

Answer 1

Use a ProcessBuilder . It makes it easy to redirect output of a command to file as shown below:

new ProcessBuilder("echo", "hello").redirectOutput(new File("output.txt")).start();

If you want to append to the output file:

new ProcessBuilder("echo", "hello").redirectOutput(Redirect.appendTo(new File("output.txt"))).start();

Answer 2

What you are executing is bash command (echo). Your java program do not work as bash interpreter

To execute any script which requires bash or shell scripting features, your need to execute that interpreter

To solve your problem you can follow below steps 1. Write your string into temp .sh file. Lets call it temp.sh 2. execute below using Runtime.getRuntime().exec

Process p = Runtime.getRuntime().exec("bash temp.sh");

bash will try to execute any command in temp.sh