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Batch file for downloading files of MinGW + MSYS

@REM ***************************************************************************
@REM
@REM Batch file for downloading files of MinGW + MSYS
@REM
@REM Version: 1.2 @ August 28, 2011
@REM
@REM *** License ***
@REM
@REM Except where otherwise noted, all of the batchs and scripts are
@REM copyrighted by http://www.FFmpegWindows.org
@REM
@REM Copyright (C) 2010-2011 http://www.FFmpegWindows.org All rights reserved.
@REM
@REM These batchs and scripts are provided "as-is," without any express or
@REM implied warranty. In no event shall the author be held liable for any
@REM damages arising from the use of them.
@REM
@REM Permission is granted to anyone to use these batchs and scripts for
@REM any purpose, including commercial applications, and to alter and
@REM redistribute it, provided that the following conditions are met:
@REM
@REM 1. All redistributions of batchs and scripts must retain all copyright
@REM    notices that are currently in place, and this list of conditions
@REM    without modification.
@REM
@REM 2. Modified versions must be plainly marked as such, and must not be
@REM    misrepresented as being the original batchs and scripts.
@REM
@REM http://www.ffmpegwindows.org
@REM
@REM ***************************************************************************

@REM check if we are running within the main batch file
@IF NOT "%IN_MINGW_MSYS_BAT%"=="1" (
	@ECHO.
	@ECHO This batch file "%~NX0" needs to be called by the main batch file.
	@ECHO.
	@PAUSE
	@EXIT /B 1
)

REM global variables: SAVE_DIR, FILE_NAME, WGET, FILE_URL, FILE_VER

REM create storage directory
IF NOT EXIST "%SAVE_DIR%" (
	MKDIR "%SAVE_DIR%"
	IF ERRORLEVEL==1 (
		ECHO   Error: *failed* to create directory "%SAVE_DIR%"
		PAUSE
		EXIT /B 1
	)
)
CD /D "%SAVE_DIR%"

REM download the file when not exists
IF NOT EXIST "%FILE_NAME%" (
	ECHO   Downloading "%FILE_NAME%" ...
	IF "%FILE_VER%"=="" (
		"%WGET%" "%FILE_URL%/%FILE_NAME%" > nul 2> nul
	) ELSE (
		"%WGET%" "%FILE_URL%/%FILE_VER%/%FILE_NAME%/download" > nul 2> nul
	)
	IF ERRORLEVEL==1 (
		ECHO   Downloading "%FILE_NAME%" *failed*
		EXIT /B 0
	)
	IF ERRORLEVEL==0 (
		ECHO   Downloading "%FILE_NAME%" done
		EXIT /B 0
	)
) ELSE (
	ECHO   "%FILE_NAME%" exists
	EXIT /B 0
)