int
find_cmd_in_path(const char cmd[], size_t path_len, char path[])
{
size_t i;
size_t paths_count;
char **paths;
paths = get_paths(&paths_count);
for(i = 0; i < paths_count; i++)
{
char tmp_path[PATH_MAX];
snprintf(tmp_path, sizeof(tmp_path), "%s/%s", paths[i], cmd);
/* Need to check for executable, not just a file, as this additionally
* checks for path with different executable extensions on Windows. */
if(executable_exists(tmp_path))
{
if(path != NULL)
{
copy_str(path, path_len, tmp_path);
}
return 0;
}
}
return 1;
}
int
external_command_exists(const char cmd[])
{
char path[PATH_MAX];
if(get_cmd_path(cmd, sizeof(path), path) == 0)
{
return executable_exists(path);
}
return 0;
}
/* Checks whether executable exists at absolute path orin directories listed in
* $PATH when path isn't absolute. Checks for various executable extensions on
* Windows. Returns boolean value describing result of the check. */
static var_t
executable_builtin(const call_info_t *call_info)
{
int exists;
char *str_val;
str_val = var_to_string(call_info->argv[0]);
if(is_path_absolute(str_val))
{
exists = executable_exists(str_val);
}
else
{
exists = (find_cmd_in_path(str_val, 0UL, NULL) == 0);
}
free(str_val);
return exists ? var_true() : var_false();
}
/* Checks whether executable exists at absolute path orin directories listed in
* $PATH when path isn't absolute. Checks for various executable extensions on
* Windows. Returns boolean value describing result of the check. */
static var_t
executable_builtin(const call_info_t *call_info)
{
int exists;
char *str_val;
str_val = var_to_string(call_info->argv[0]);
if(strpbrk(str_val, PATH_SEPARATORS) != NULL)
{
exists = executable_exists(str_val);
}
else
{
exists = (find_cmd_in_path(str_val, 0UL, NULL) == 0);
}
free(str_val);
return var_from_bool(exists);
}
int main(int argc, char **argv)
{
char *me = argv[0], *data, **new_argv;
char *exe_path, *lib_path, *dll_path;
int start, prog_end, end, count, fd, v, en, x11;
int argpos, inpos, collcount = 1, fix_argv;
if (config[7] == '[') {
write_str(2, argv[0]);
write_str(2, ": this is an unconfigured starter\n");
return 1;
}
if (me[0] == '/') {
/* Absolute path */
} else if (has_slash(me)) {
/* Relative path with a directory: */
char *buf;
long buflen = 4096;
buf = (char *)malloc(buflen);
me = path_append(getcwd(buf, buflen), me);
} else {
/* We have to find the executable by searching PATH: */
char *path = copy_string(getenv("PATH")), *p, *m;
int more;
if (!path) {
path = "";
}
while (1) {
/* Try each element of path: */
for (p = path; *p && (*p != ':'); p++) { }
if (*p) {
*p = 0;
more = 1;
} else
more = 0;
if (!*path)
break;
m = path_append(path, me);
if (executable_exists(m)) {
if (m[0] != '/')
m = path_append(getcwd(NULL, 0), m);
me = m;
break;
}
free(m);
if (more)
path = p + 1;
else
break;
}
}
/* me is now an absolute path to the binary */
/* resolve soft links */
while (1) {
int len, bufsize = 127;
char *buf;
buf = (char *)malloc(bufsize + 1);
len = readlink(me, buf, bufsize);
if (len < 0) {
if (errno == ENAMETOOLONG) {
/* Increase buffer size and try again: */
bufsize *= 2;
buf = (char *)malloc(bufsize + 1);
} else
break;
} else {
/* Resolve buf relative to me: */
buf[len] = 0;
buf = absolutize(buf, me);
me = buf;
buf = (char *)malloc(bufsize + 1);
}
}
start = as_int(config + 8);
prog_end = as_int(config + 12);
end = as_int(config + 16);
count = as_int(config + 20);
x11 = as_int(config + 24);
fix_argv = try_elf_section(me, &start, &prog_end, &end);
{
int offset, len;
offset = _coldir_offset;
while (1) {
len = strlen(_coldir + offset);
offset += len + 1;
if (!_coldir[offset])
break;
collcount++;
}
}
data = (char *)malloc(end - prog_end);
new_argv = (char **)malloc((count + argc + (2 * collcount) + 8) * sizeof(char*));
fd = open(me, O_RDONLY, 0);
lseek(fd, prog_end, SEEK_SET);
{
int expected_length = end - prog_end;
if (expected_length != read(fd, data, expected_length)) {
printf("read failed to read all %i bytes from file %s\n", expected_length, me);
abort();
}
}
close(fd);
exe_path = data;
data = next_string(data);
lib_path = data;
data = next_string(data);
exe_path = absolutize(exe_path, me);
lib_path = absolutize(lib_path, me);
# ifdef OS_X
# define LD_LIB_PATH "DYLD_LIBRARY_PATH"
# else
# define LD_LIB_PATH "LD_LIBRARY_PATH"
# endif
if (*lib_path) {
dll_path = getenv(LD_LIB_PATH);
if (!dll_path) {
dll_path = "";
}
dll_path = string_append(dll_path, ":");
dll_path = string_append(lib_path, dll_path);
dll_path = string_append(LD_LIB_PATH "=", dll_path);
putenv(dll_path);
}
new_argv[0] = me;
argpos = 1;
inpos = 1;
/* Keep all X11 flags to the front: */
if (x11) {
int n;
while (inpos < argc) {
n = is_x_flag(argv[inpos]);
if (!n)
break;
if (inpos + n > argc) {
write_str(2, argv[0]);
write_str(2, ": missing an argument for ");
write_str(2, argv[inpos]);
write_str(2, "\n");
return 1;
}
while (n--) {
new_argv[argpos++] = argv[inpos++];
}
}
}
/* Add -X and -S flags */
{
int offset, len;
offset = _coldir_offset;
new_argv[argpos++] = "-X";
new_argv[argpos++] = absolutize(_coldir + offset, me);
while (1) {
len = strlen(_coldir + offset);
offset += len + 1;
if (!_coldir[offset])
break;
new_argv[argpos++] = "-S";
new_argv[argpos++] = absolutize(_coldir + offset, me);
}
}
if (fix_argv) {
/* next three args are "-k" and numbers; fix
the numbers to match start and prog_end */
fix_argv = argpos + 1;
}
/* Add built-in flags: */
while (count--) {
new_argv[argpos++] = data;
data = next_string(data);
}
/* Propagate new flags (after the X11 flags) */
while (inpos < argc) {
new_argv[argpos++] = argv[inpos++];
}
new_argv[argpos] = NULL;
if (fix_argv) {
new_argv[fix_argv] = num_to_string(start);
new_argv[fix_argv+1] = num_to_string(prog_end);
}
/* Execute the original binary: */
v = execv(exe_path, new_argv);
en = errno;
write_str(2, argv[0]);
write_str(2, ": failed to start ");
write_str(2, exe_path);
write_str(2, " (");
write_str(2, strerror(en));
write_str(2, ")\n");
if (*lib_path) {
write_str(2, " used library path ");
write_str(2, lib_path);
write_str(2, "\n");
}
return v;
}
