#ifndef CHILDPROC_MD_H
#define CHILDPROC_MD_H

#include <sys/types.h>

#ifdef __APPLE__
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#endif

/* This is one of the rare times it's more portable to declare an
 * external symbol explicitly, rather than via a system header.
 * The declaration is standardized as part of UNIX98, but there is
 * no standard (not even de-facto) header file where the
 * declaration is to be found.  See:
 * http://www.opengroup.org/onlinepubs/009695399/functions/environ.html
 * http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_02.html
 *
 * "All identifiers in this volume of IEEE Std 1003.1-2001, except
 * environ, are defined in at least one of the headers" (!)
 */
extern char **environ;

/* These numbers must be the same as the Enum in UNIXProcess.java
 * Must be a better way of doing this.
 */
#define MODE_CLONE 1
#define MODE_FORK 2
#define MODE_VFORK 3
#define MODE_SPAWN 4

typedef struct _ChildStuff
{
    int in[2];
    int out[2];
    int err[2];
    int fail[2];
    int childenv[2]; 
    int fds[3];
    int mode;
    const char **argv;
    int argc;
    const char **envv;
    const char *pdir;
    int redirectErrorStream;
    void *clone_stack;
} ChildStuff;

/* following used in addition when mode is SPAWN */
typedef struct _SpawnInfo {
    int nargv; /* number of argv array elements  */
    int argvBytes; /* total number of bytes in argv array */
    int nenvv; /* number of envv array elements  */
    int envvBytes; /* total number of bytes in envv array */
    int dirlen; /* length of home directory string */
    int parentPathLen; /* length of parentPath string */
    int nparentPathv; /* number of elements in parentPathv array */
    int parentPathvBytes; /* total number of bytes in parentPathv array */
} SpawnInfo;

extern const char *parentPath;
extern const char * const *parentPathv;

ssize_t restartableWrite(int fd, const void *buf, size_t count);
int restartableDup2(int fd_from, int fd_to);
int restartableClose(int fd);
int closeSafely(int fd);
int isAsciiDigit(char c);
int closeDescriptors(void);
int moveDescriptor(int fd_from, int fd_to);

int magicNumber();
ssize_t readFully(int fd, void *buf, size_t nbyte);
void initVectorFromBlock(const char**vector, const char* block, int count);
void execve_as_traditional_shell_script(const char *file,
                                        const char *argv[],
                                        const char *const envp[]);
void execve_with_shell_fallback(int mode, const char *file,
                                const char *argv[],
                                const char *const envp[]);
void JDK_execvpe(int mode, const char *file,
                 const char *argv[],
                 const char *const envp[]);
int childProcess(void *arg);

#endif