Groovy example source code file (base.c)

This example Groovy source code file (base.c) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

classpath, classpath, in, java, java_class_name, linux, linux, macosx, macosx, newclasspath, path, unix, unix, vm

The Groovy base.c source code

#ifdef __APPLE__
#ifdef __MACH__
#define MACOSX
#define UNIX
#endif
#endif

#ifdef __linux__
#define UNIX
#define LINUX
#endif

#ifdef UNIX
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#endif

#ifdef LINUX
#include <unistd.h>
#include <linux/limits.h>
#include <malloc.h>
#endif

#ifdef MACOSX
#include <mach-o/dyld.h>
#include <sys/param.h>
#endif

int main(int argc, char* argv[]) {

  // Get the location of the executable -- platform specific
#ifdef UNIX
  char *jarexe = malloc((MAXPATHLEN+2)*sizeof(char));
#endif

#ifdef MACOSX
  uint32_t length = MAXPATHLEN + 2;
  while (_NSGetExecutablePath((char*)jarexe, &length) == -1) {
    free(jarexe);
    jarexe = malloc((length)*sizeof(char));
  }
#endif

#ifdef LINUX
  char temp[PATH_MAX];
  sprintf(temp, "/proc/%d/exe", getpid());
  realpath(temp, jarexe);
#endif

  // Setup the command line.
  // TODO: Add -J support for passing Java options
  char* argv2[argc+2];
  argv2[0] = "java";
  argv2[1] = JAVA_CLASS_NAME;

  // Setup the CLASSPATH environment
  char *CLASSPATH = (char*) getenv("CLASSPATH");
  if (!CLASSPATH) CLASSPATH="";
  char *NEWCLASSPATH = (char*) calloc(strlen(CLASSPATH)+1+strlen(jarexe)+1, sizeof(char)); // +1 for :, +1 for null terminator
  sprintf(NEWCLASSPATH, "%s:%s", jarexe, CLASSPATH);
  setenv("CLASSPATH", NEWCLASSPATH, 1);

  // Setup the rest of the command line that was passed in.
  // TODO: This will also be affected by -J options
  int i;
  for (i = 1; i < argc; i++) {
    argv2[i+1] = argv[i];
  }
  argv2[argc+1] = 0;

  // Execute java
#ifdef UNIX
  free(jarexe);
  execvp("java", argv2);
#endif

  // Report if the exec fails
  printf("Cannot execute '");
  for (i = 0; i < argc+1; i ++) { printf("%s ", argv2[i]); }
#ifdef UNIX
  printf("', caused by error: %d\n.  In order to run %s you must have the Java VM you want to use in your PATH", errno, argv[0]);
#endif
}