MODULE Blank;

(* ------------------------------------------------------------------------
 * (c) 2010 by Alexander Iljin
 * ------------------------------------------------------------------------ *)

IMPORT In;

(** -----------------------------------------------------------------------
  * This console program returns 1 if a non-blank character was read from
  * StdIn.
  * ----------------------------------------------------------------------- *)

VAR
   ch: CHAR;
BEGIN
   In.Open;
   In.Char (ch);
   WHILE In.Done & (ch <= ' ') DO
      In.Char (ch);
   END;
   IF ~In.Done THEN
      HALT (1);
   END;
END Blank.

REM some commands

CALL :BLANK %check_string%

REM some commands


GOTO :EOF

:BLANK
IF not "%1"=="" EXIT /b 1

CALL :CHECK type test.txt

GOTO :EOF

:CHECK
FOR /F %%i IN ('%*') DO EXIT /b 1

:: Make sure that the log message contains some text.
set result=1
for /f "eol= " %%i in (%TMPFILE%) do set result=0
if %result% == 1 (
  echo Commits with empty log message are not allowed. >&2
)

del %TMPFILE% > NUL
exit %result%

@echo off
set REPOS="%1"
set TXN="%2"
set TMPFILE=Log%RANDOM%.tmp

:: Make sure that the log message contains some text.
svnlook log -t %TXN% %REPOS% > %TMPFILE%
call :CheckBlank %TMPFILE%
set result=%errorlevel%
if %result% == 1 (
  echo Commits with empty log message are not allowed. >&2
)

del %TMPFILE% > NUL
exit %result%

:: Return 1 if %1 is a blank file, otherwise return 0
:CheckBlank
for /f "eol= " %%i in (%1) do exit /b 0
exit /b 1