C program compilation from a java program

Question

I am trying to compile a c program from a java program on Linux platform. My snippet is.

          ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/gcc",
          "-c","/hipad/UserProject/example.c");

          Process proc = processBuilder.start();

There is no error during compilation of java program but I am not able to get .o file. I tried to find out solutions but no one is working. Any suggestion.....

Does it work fine when you compile the c program manually with the same options ? — slayedbylucifer, Dec 09 '13 at 05:05
the .o file probably appears in the current working directory, whatever that is. — hyde, Dec 09 '13 at 05:06
I can see that you are using a *nix machine right? I've noticed that providing the entire file path for files in that will help with most situations..... — user2277872, Dec 09 '13 at 05:16
@Staven What's it matter? I can think of many reasons ... perhaps the OP is developing a C IDE in Java. — Jim Balter, Dec 09 '13 at 05:29
@hyde- You are right sir, I could not notice that .o file was created on the current directory(eclipse). Thanks alot. — DEV, Dec 09 '13 at 08:44
@DEV Cool. I'll write that as an answer a bit later, With some more details, so you can accept it. — hyde, Dec 09 '13 at 14:48

score 3 · Accepted Answer · answered Dec 09 '13 at 19:57

The default working directory of a child process is what ever directory the Java process has as a working directory, which usually is where it was launched from. And by default gcc writes output files to current working directory. That's where you should find example.o.

There are two simple ways to solve this. You can give gcc -o option and full path and name of desired output file, or you can set working directory of child process, like this:

ProcessBuilder processBuilder =
    new ProcessBuilder("/usr/bin/gcc", "-c","example.c"); // source in working dir
processBuilder.directory(new File ("/hipad/UserProject")); // or whatever
Process proc = processBuilder.start();

See ProcessBuilder javadoc for more info.

C program compilation from a java program

1 Answers1

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