CODEWITHSUNDEEP
javalinuxshell
Lukas Bystricky
Lukas Bystricky

Reputation: 1272

Shell script call command line application

I have a Java program which I'd like to call inside a linux shell script. The Java program takes a user input from the command line.

I read somewhere that I can use echo to mimic user input as follows:

 java myProgram
 echo 1000
 echo

However this doesn't work for me, the program is still waiting for the user input. Is there something I'm doing wrong? I can't imagine this is a difficult task.

Upvotes: 0

Views: 107

Answers (3)

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279940

I think you should find the process id of your java process and then write to its /proc directory.

Say the id of the Java process is 4321, then output to 

/proc/4321/fd/0

Upvotes: 0

Reimeus
Reimeus

Reputation: 159754

Why not just pass in the value as an argument

java myProgram 1000

Upvotes: 1

RaptorDotCpp
RaptorDotCpp

Reputation: 1465

You can use echo, but in a pipeline.

echo 1000 | java myProgram

If you want to send a file, you can use cat:

cat file.txt | java myProgram

Upvotes: 2

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