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/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1998 Institut National de Recherche en Informatique et */
/* Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
/* The launcher for bytecode executables (if #! is not working) */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../config/s.h"
#ifdef HAS_UNISTD
#include <unistd.h>
#endif
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "../byterun/exec.h"
char * default_runtime_path = RUNTIME_NAME;
#define MAXPATHLEN 1024
#ifndef S_ISREG
#define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
#endif
#ifndef SEEK_END
#define SEEK_END 2
#endif
static char * searchpath(char * name)
{
static char fullname[MAXPATHLEN + 1];
char * path;
char * p;
char * q;
struct stat st;
for (p = name; *p != 0; p++) {
if (*p == '/') return name;
}
path = getenv("PATH");
if (path == NULL) return name;
while(1) {
for (p = fullname; *path != 0 && *path != ':'; p++, path++)
if (p < fullname + MAXPATHLEN) *p = *path;
if (p != fullname && p < fullname + MAXPATHLEN)
*p++ = '/';
for (q = name; *q != 0; p++, q++)
if (p < fullname + MAXPATHLEN) *p = *q;
*p = 0;
if (stat(fullname, &st) == 0 && S_ISREG(st.st_mode)) break;
if (*path == 0) return name;
path++;
}
return fullname;
}
static unsigned long read_size(char * ptr)
{
unsigned char * p = (unsigned char *) ptr;
return ((unsigned long) p[0] << 24) + ((unsigned long) p[1] << 16) +
((unsigned long) p[2] << 8) + p[3];
}
static char * read_runtime_path(int fd)
{
char buffer[TRAILER_SIZE];
static char runtime_path[MAXPATHLEN];
unsigned path_size, code_size, prim_size, data_size;
unsigned symbol_size, debug_size, size;
lseek(fd, (long) -TRAILER_SIZE, SEEK_END);
if (read(fd, buffer, TRAILER_SIZE) < TRAILER_SIZE) return NULL;
path_size = read_size(buffer);
code_size = read_size(buffer + 4);
prim_size = read_size(buffer + 8);
data_size = read_size(buffer + 12);
symbol_size = read_size(buffer + 16);
debug_size = read_size(buffer + 20);
if (path_size > MAXPATHLEN) return NULL;
if (path_size == 0) return default_runtime_path;
size = path_size + code_size + prim_size +
data_size + symbol_size + debug_size + TRAILER_SIZE;
lseek(fd, -size, SEEK_END);
if (read(fd, runtime_path, path_size) != path_size) return NULL;
runtime_path[path_size - 1] = 0;
return runtime_path;
}
static void errwrite(char * msg)
{
write(2, msg, strlen(msg));
}
int main(int argc, char ** argv)
{
char * truename, * runtime_path;
int fd;
truename = searchpath(argv[0]);
fd = open(truename, O_RDONLY);
if (fd == -1 || (runtime_path = read_runtime_path(fd)) == NULL) {
errwrite(truename);
errwrite(" not found or is not a bytecode executable file\n");
return 2;
}
execv(runtime_path, argv);
errwrite("Cannot exec ");
errwrite(runtime_path);
errwrite("\n");
return 2;
}
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