Function appendShellStringNoError

src/fe_utils/string_utils.c:614–711

}

bool
appendShellStringNoError(PQExpBuffer buf, const char *str)
{
#ifdef WIN32
	int			backslash_run_length = 0;
#endif
	bool		ok = true;
	const char *p;

	/*
	 * Don't bother with adding quotes if the string is nonempty and clearly
	 * contains only safe characters.
	 */
	if (*str != '\0' &&
		strspn(str, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_./:") == strlen(str))
	{
		appendPQExpBufferStr(buf, str);
		return ok;
	}

#ifndef WIN32
	appendPQExpBufferChar(buf, '\'');
	for (p = str; *p; p++)
	{
		if (*p == '\n' || *p == '\r')
		{
			ok = false;
			continue;
		}

		if (*p == '\'')
			appendPQExpBufferStr(buf, "'\"'\"'");
		else
			appendPQExpBufferChar(buf, *p);
	}
	appendPQExpBufferChar(buf, '\'');
#else							/* WIN32 */

	/*
	 * A Windows system() argument experiences two layers of interpretation.
	 * First, cmd.exe interprets the string.  Its behavior is undocumented,
	 * but a caret escapes any byte except LF or CR that would otherwise have
	 * special meaning.  Handling of a caret before LF or CR differs between
	 * "cmd.exe /c" and other modes, and it is unusable here.
	 *
	 * Second, the new process parses its command line to construct argv (see
	 * https://msdn.microsoft.com/en-us/library/17w5ykft.aspx).  This treats
	 * backslash-double quote sequences specially.
	 */
	appendPQExpBufferStr(buf, "^\"");
	for (p = str; *p; p++)
	{
		if (*p == '\n' || *p == '\r')
		{
			ok = false;
			continue;
		}