Function find_other_exec

src/common/exec.c:326–356

* Find another program in our binary's directory, * then make sure it is the proper version. */

 * then make sure it is the proper version.
 */
int
find_other_exec(const char *argv0, const char *target,
				const char *versionstr, char *retpath)
{
	char		cmd[MAXPGPATH];
	char		line[MAXPGPATH];

	if (find_my_exec(argv0, retpath) < 0)
		return -1;

	/* Trim off program name and keep just directory */
	*last_dir_separator(retpath) = '\0';
	canonicalize_path(retpath);

	/* Now append the other program's name */
	snprintf(retpath + strlen(retpath), MAXPGPATH - strlen(retpath),
			 "/%s%s", target, EXE);

	if (validate_exec(retpath) != 0)
		return -1;

	snprintf(cmd, sizeof(cmd), "\"%s\" -V", retpath);

	if (!pipe_read_line(cmd, line, sizeof(line)))
		return -1;

	if (strcmp(line, versionstr) != 0)
		return -2;

	return 0;
}


/*