How to delete empty folders and its subfolders

1. Delete only files having size condition

아래 내용은 오직 100000000바이트보다 작은 크기의 파일만을 제거하기 위한 코드이다. 시작 패스를 명확히 지정해 주어야 하면 이때 사용하는 옵션이 /P 이다.

/S� 옵션은 모든 하위 디렉토리를 순회하면서 동작하게 한다.

To ensure that only files are deleted and not directories, you can add a condition to check if the item being processed is a file before attempting to delete it. Here's the modified command:

forfiles /s /p "C:\path\to\directory" /c "cmd /c if @isdir==FALSE if @fsize LSS 10000000 del /f /q @path"

In this version, `@isdir==FALSE` is used to check if the item is not a directory (i.e., it's a file). So, before attempting to delete the file, it verifies that the item is indeed a file.

Again, please ensure to replace `"C:\path\to\directory"` with the actual path to your subdirectory, and test the command on a small sample of files to ensure it behaves as expected before applying it to a larger set of files.

먼저 echo를 통해서 정확히 동작하는 지를 검토 한 후 사용하라.

1.1. 유사한 예

아래 코드는 파일만을 삭제하는 코드로 @path 에서 나타나는 패스정보로 인해 문제가 발생할 수 있어 특별히 파일이라고 명세하여 동작 시킨다.

Z:\>forfiles /s /m *.* /c "cmd /c if @fsize lss 1048576 del /q� @path

rem very careful for the command below.

@echo off

rem reference - https://learn.microsoft.com/ko-kr/windows-server/administration/windows-commands/forfiles

rem the below command is more proper for the deletion for less and equal than 20,000,000 bytes

forfiles /s /m *.* /c "cmd /c if @fsize leq 20000000 echo @file"

rem to remove the files, use the following command.

forfiles /s /m *.* /c "cmd /c if @fsize leq 20000000 del /q @file"

2. Delete Empty folders

아래 코드는 모든 폴더를 삭제하는 기본코드이다. 아래 코드를 기반으로 배치코드를 업데이트 하고자 한다.

for /d /r %d in (�*.*�) do rd �%d�

이 코드를 기반으로 빈 폴더만을 검색하고 삭제할 수 있도록 코드를 수정한다.

REM to find the empty folders

Simple example to remove empty folder � However, it is not fit to delete all subfolders which is empty

Y:\>For /R /D %i in (*) do @(dir /a-d %i\* >nul 2>&1 || echo %i is empty)

위 코드는 만약 아래에 폴더가 있더라도 현재의 폴더에 파일이 없으면 삭제하는 문제가 있다.

따라서 아래와 같이 수정한다.

REM to check the subdirectory is exist and it has a file.

for /f "delims=" %i in ('dir /s /b /ad ^| sort /r') do @(echo %i is directory now we search && dir /a /b "%i" | findstr /r /c:".*" >nul || echo %i is empty)

위 코드는 명확히 폴더가 비어 있는지 확인하고 최하위 폴더로부터 삭제하여 상위폴더 방향으로 이동한다. 이때 sort /r이 역순으로 삭제하는 데 사용된다.

2.1. 시험결과

Y:\>for /f "delims=" %i in ('dir /s /b /ad ^| sort /r') do @(dir /a /b "%i" | findstr /r /c:".*" >nul || rmdir "%i" && echo "%i" is deleted)

"Y:\hlll\kklll\llkklll" is deleted

"Y:\hlll\kklll" is deleted

"Y:\hlll" is deleted

"Y:\hello world" is deleted

2.2. 추가 설명

1) for /f "delims=" %i in ('dir /s /b /ad ^| sort /r'): This part of the command sets up a loop to iterate over the output of the command inside the single quotes. Here's what each component does:

� for /f: This is a loop construct in batch scripting that iterates over the lines of a command's output.

� "delims=": This option tells the loop not to use any delimiter, so it treats each line as a whole.

� %i: This is the loop variable that represents each line of output from the command.

� 'dir /s /b /ad ^| sort /r': This command inside the single quotes lists all directories and subdirectories (/s /ad) in the current directory and its subdirectories in a bare format (/b). The ^| is used to escape the pipe character (|) because the command is executed inside single quotes. sort /r sorts the directories in reverse order, so that deeper subdirectories are processed before their parent directories.

2) do @(dir /a /b "%i" | findstr /r /c:".*" >nul || rmdir "%i" && echo "%i" is deletec): This part of the command specifies what to do for each iteration of the loop. Here's what each component does:

� @(dir /a /b "%i" | findstr /r /c:".*" >nul || rmdir "%i" && echo "%i" is deletec): This executes a series of commands for each directory. Here's what each command does:

� dir /a /b "%i": This lists all files and directories (including hidden ones) in the directory specified by %i in a bare format (/b), without additional information (/a).

� |: This is the pipe operator, which redirects the output of the dir command to the input of the next command (findstr).

� findstr /r /c:".*": This command uses regular expressions to search for any line containing any sequence of characters (.*). It effectively checks if there are any files or subdirectories present in the directory.

� >nul: This discards the output of the findstr command.

� ||: This is the logical OR operator. It executes the command following it (rmdir "%i" && echo "%i" is deleted) only if the previous command fails, i.e., if findstr doesn't find any files or subdirectories in the directory.

� rmdir "%i": This command attempts to remove the directory specified by %i. If the directory is empty, it will be deleted.

� &&: This is the logical AND operator. It executes the command following it (echo "%i" is deleted) only if the previous command (rmdir "%i") succeeds, i.e., if the directory is successfully deleted.

� echo "%i" is deleted: This command echoes the path of the deleted directory.

Overall, this command iterates over all directories and subdirectories in the current directory, sorts them in reverse order, and for each directory, checks if it's empty. If it's empty, it attempts to delete it and prints a message indicating whether it was successfully deleted.

2.3. Forfiles

1) 옵션

/P <pathname> 검색을 시작 하는 경로 지정 합니다. 기본적으로 현재 작업 디렉터리에서 시작 검색 합니다.

/M <searchmask>����������� 지정 된 검색 마스크에 따라 파일을 검색합니다. 기본 검색 마스크는 .입니다 *.

/S����������� 하위 디렉터리에서 재귀적으로 검색하도록 forfiles 명령을 지시합니다.

/C <command> 각 파일에 지정된 된 명령을 실행합니다. 명령 문자열은 큰따옴표로 묶어야 합니다. 기본 명령은 .입니다 "cmd /c echo @file".

/D [{+\|-}][{<date> | <days>}]���� 지정된 시간 프레임 내에 마지막으로 수정된 날짜가 있는 파일을 선택합니다.

마지막으로 수정한 날짜가 지정된 날짜보다 늦거나 같+거나 ()와 같거나 같은- 파일을 선택합니다. 여기서 날짜 는 MM/DD/YYYY 형식입니다.

마지막으로 수정한 날짜가 현재 날짜보다 늦거나 같거나 같은+ 파일을 선택하고, 현재 날짜보다 같거나() 지정된 일 수를 뺀 날짜보다 같거나- 같은 파일을 선택합니다.

유효한 일 값은 0~32,768 범위의 숫자를 포함합니다. 기호가 없으면 지정 된 경우 + 기본적으로 사용 됩니다.

/?����������� cmd 창에 도움말 텍스트를 표시합니다.

2) Use variables� @

변수����� 설명

@FILE��� 파일 이름입니다.

@FNAME����������� 확장명 없이 파일 이름입니다.

@EXT��� 파일 이름 확장명입니다.

@PATH 파일의 전체 경로입니다.

@RELPATH��������� 파일의 상대 경로입니다.

@ISDIR 파일 형식을 디렉터리 이면 TRUE로 평가 합니다. 그렇지 않은 경우이 변수를 FALSE로 평가합니다.

@FSIZE 파일 크기 (바이트)에서입니다.

@FDATE�������������� 파일에 마지막으로 수정한 날짜 스탬프입니다.

@FTIME�������������� 파일의 마지막 수정된 타임 스탬프입니다.

2.4. If � as batch command, we can use

2.4.1. 개요

if문은 조건에 따라 명령을 수행하는데 이때 do 는 사용되지 않는다는 것에 유의하고, 또, OR /AND 에 대한 구문형식을 잘 익혀두는 것이 중요하다.

2.4.2. 기본형태

기본적인 형태In the textbox below, we can use command directly after the condition check.

�� IF [NOT] EXIST filename command

�� IF [NOT] EXIST filename (command) ELSE (command)

2.4.3. 비교연산자

�� IF [/I] [NOT] item1==item2 command

�� IF [/I] [NOT] "item1" == "item2" command

�� IF [/I] item1 compare-op item2 command

�� IF [/I] item1 compare-op item2 (command) ELSE (command)

2.4.4. Error Check Syntax

�� IF [NOT] DEFINED variable command

�� IF [NOT] ERRORLEVEL number command

�� IF CMDEXTVERSION number command

key

�� item������� A text string or environment variable, for more complex

�������������� comparisons, a variable can be modified using

�������������� either Substring or Search syntax.

�� command���� The command to perform.

�� filename��� A file to test or a wildcard pattern.

�� NOT�������� Perform the command if the condition is false.

�� ==��������� Perform the command if the two strings are equal.

�� /I��������� Do a case Insensitive string comparison.

�� compare-op� Can be one of:

���������������� EQU : Equal

���������������� NEQ : Not equal

���������������� LSS : Less than <

���������������� LEQ : Less than or Equal <=

���������������� GTR : Greater than >

���������������� GEQ : Greater than or equal >=

�������������� This 3 digit syntax is used because the > and <

�������������� symbols are recognised as redirection operators

IF will only parse numbers when one of (EQU, NEQ, LSS, LEQ, GTR, GEQ) is used.

The == comparison operator always results in a string comparison.

Compare strings that contain Spaces by using "double quotes"

The IF command can seem flaky if any spaces exist in the comparison strings. for example these commands all seem like they work:

IF 'ab' == 'a b' Echo OK

IF [ab] == [a b] Echo OK

But if you reverse the logic to see if they are not equal, the code will fail and thow an error:

IF 'ab' NEQ 'a b' Echo OK

IF [ab] NEQ [a b] Echo OK

Similarly this will fail:

IF 'a b' == 'a b' Echo OK

The problem with the above, is that single quotes have no special meaning to CMD, so when it reaches a space it assumes that�s the end of the string.

These versions using double quotes will all work:

IF "ab" == "a b" Echo OK

IF "ab" NEQ "a b" Echo OK

IF NOT "ab" == "a b"

So then you think, OK I�ll just use double quotes. However there is one remaining gotcha, if the item you are comparing is a quoted filename, so it already contains double quotes, you have an escape sequence:

IF ""long filename"" EQU "something" Echo OK

That will break because the "" acts as an escape. To prevent that from happening strip any quotes from the strings being compared.

In addition to spaces, the above applies to all other delimiters [Comma],[Semicolon], [Equals], [Space] [Tab].

Either the delimiters must be individually escaped with a caret ^ or the whole string must be "quoted".

Test if a variable is empty

To test for the existence of a command line parameter - use empty brackets like this:

IF [%1] == [] ECHO Value Missing

or

IF [%1] EQU [] ECHO Value Missing

When comparing against a variable that may be empty, we include a pair of brackets [ ] so that if the variable does happen to be empty the IF command still has something to compare: IF [] EQU [] will return True.

결국 []는 Escape문자도 아니고 구현방법의 수단 중의 하나이다.

You can in fact use almost any character for this a '~' or curly brackets, { } or even the number 4, but square brackets tend to be chosen because they don�t have any special meaning.

When working with filenames/paths you should always surround them with quotes, if %_myvar% contains "C:\Some Path" then your comparison becomes IF ["C:\Some Path"] EQU []

if %_myvar% could contain empty quotes, "" then your comparison should become IF [%_myvar%] EQU [""]

if %_myvar% will never contain quotes, then you can use quotes in place of the brackets IF "%_myvar%" EQU ""

However with this pattern if %_myvar% does unexpectedly contain quotes, you will get IF ""C:\Some Path"" EQU "" those doubled quotes, act as an escape and will break the comparison.

2.4.5. Test if a variable is NULL

In the case of a variable that might be NULL - a null variable will remove the variable definition altogether, so testing for a NULL becomes:

IF NOT DEFINED _example ECHO Value Missing

IF DEFINED will return true if the variable contains any value (even if the value is just a space).

To test for the existence of a variable use SET VariableName, or IF DEFINED VariableName

Test the existence of files and folders

IF EXIST filename�� Will detect the existence of a file or a folder.

The script empty.cmd will show if the folder is empty or not (this is not case sensitive).

2.4.6. Parenthesis

Parenthesis can be used to split commands across multiple lines. This enables writing more complex IF� ELSE� commands:

IF EXIST filename.txt (

��� Echo deleting filename.txt

��� Del filename.txt

�) ELSE (

��� Echo The file was not found.

�)

When combining an ELSE statement with parentheses, always put the opening parenthesis on the same line as ELSE.

�) ELSE (�� This is because CMD does a rather primitive one-line-at-a-time parsing of the command.

When using parentheses the CMD shell will expand [read] all the variables at the beginning of the code block and use those values even if the variables value has just been changed. Turning on DelayedExpansion will force the shell to read variables at the start of every line.

2.4.7. Pipes

여러 명령을 수행해야 하는 경우에 아래와 같이 사용이 가능하다. 평가되는 순서는 왼쪽에서 오른쪽 방향으로 수행된다.

IF SomeCondition Command1 | Command2 is equivalent to:

(IF SomeCondition Command1 ) | Command2

The pipe is always created and Command2 is always run, regardless whether SomeCondition is TRUE or FALSE

한 조건에서 여러 명령을 수행하는 경우에는 다음과 같이 괄호 표기를 이용하여 여러 명령을 하나의 조건에서 수행하도록 한다.

IF SomeCondition (Command1 | Command2)

If the condition is met then Command1 will run, and its output will be piped to Command2.

2.4.8. AND 조건

NOT은 직접적으로 사용되지만� AND 의 경우는 다음과 같이 사용된다.

IF SomeCondition (

�� IF SomeOtherCondition (

���� Command_if_both_are_true

�� )

)

두 조건 중 하나가 참인지 확인하기 위해서, 다음과 같이 임시변수를 이용한다.

Set "_tempvar="

If SomeCondition Set "_tempvar=1"

If SomeOtherCondition Set "_tempvar=1"

if %_tempvar% EQU 1 Command_to_run_if_either_is_true

2.4.9. 숫자의 경우

숫자의 경우에는 다음의 비교 연산자를 사용할 수 있다. 문자의 경우는 �==�을 사용하였다.

IF only parses numbers when one of the compare-op operators (EQU, NEQ, LSS, LEQ, GTR, GEQ) is used.

The == comparison operator always results in a string comparison.

This is an important difference because if you compare numbers as strings it can lead to unexpected results: "2" will be greater than "19" and "026" will be less than "10".

2.4.10. 예제

Correct numeric comparison:

IF 2 GEQ 15 echo "bigger"

Using parentheses or quotes will force a string comparison:

IF (2) GEQ (15) echo "bigger"

IF "2" GEQ "15" echo "bigger"

This behaviour is exactly opposite to the SET /a command where quotes are required.

IF should work within the full range of 32 bit signed integer numbers (-2,147,483,648 through 2,147,483,647)

C:\> if 2147483646 GEQ 2147483647 (Echo Larger) Else (Echo Smaller)

Smaller�� ⇨ correct

C:\> if 2147483647 GEQ 2147483648 (Echo Larger) Else (Echo Smaller)

Larger�� ⇨ wrong due to overflow

C:\> if -2147483649 GEQ -2147483648 (Echo Larger) Else (Echo Smaller)

Larger�� ⇨ wrong due to overflow

You can perform a string comparison on very long numbers, but this will only work as expected when the numbers are exactly the same length:

C:\> if "2147483647" GEQ "2147483648" (Echo Larger) Else (Echo Smaller)

Smaller�� ⇨ correct

2.4.11. Wildcards

Wildcards are not supported by IF, so %COMPUTERNAME% == SS6* will not match SS64

A workaround is to retrieve the substring and compare just those characters:

SET _prefix=%COMPUTERNAME:~0,3%

IF %_prefix% == SS6 GOTO they_matched

2.4.12. ERRORLEVEL

There are two different methods of checking an errorlevel, the first syntax ( IF ERRORLEVEL ... ) provides compatibility with ancient batch files from the days of Windows 95.

The second method is to use the %ERRORLEVEL% variable available in Windows 2000 or newer.

IF ERRORLEVEL n statements should be read as IF Errorlevel >= number

i.e.

IF ERRORLEVEL 0 will return TRUE whether the errorlevel is 0, 1 or 5 or 64

IF ERRORLEVEL 1 will return TRUE whether the errorlevel is 1 or 5 or 64

IF NOT ERRORLEVEL 1 means if ERRORLEVEL is less than 1 (Zero or negative).

This is not very readable or user friendly and does not easily account for negative error numbers.

Using the %ERRORLEVEL% variable is a more logical method of checking Errorlevels:

IF %ERRORLEVEL% NEQ 0 Echo An error was found

IF %ERRORLEVEL% EQU 0 Echo No error found

IF %ERRORLEVEL% EQU 0 (Echo No error found) ELSE (Echo An error was found)

IF %ERRORLEVEL% EQU 0 Echo No error found || Echo An error was found

This allows you to trap errors that can be negative numbers, you can also test for specific errors:

IF %ERRORLEVEL% EQU 64 ...

To deliberately raise an ERRORLEVEL in a batch script use the EXIT /B command.

It is possible (though not a good idea) to create a string variable called %ERRORLEVEL% (user variable)

if present such a variable will override and prevent the system variable %ERRORLEVEL% from being read by commands such as ECHO and IF.

If Command Extensions are disabled IF will only support direct comparisons: IF ==, IF EXIST, IF ERRORLEVEL

also the system variable CMDEXTVERSION will be disabled.

In early versions of Windows NT/XP comparisons made using == would include the spaces before and after the ==, so for backwards compatibility you may still see commands written as IF alpha==beta rather than IF alpha == beta

IF does not, by itself, set or clear the Errorlevel.

IF is an internal command.

Examples

Does a specific file exist:

IF EXIST C:\logs\install.log (Echo Complete) ELSE (Echo failed)

Does any file exist:

IF EXIST C:\logs\*.log (Echo Log file exists)

Does a variable exist:

IF DEFINED _department ECHO This is for %_department%.

IF DEFINED _commission SET /A "_salary=%_salary% + %_commission%"

Do we have Command Processor Extensions set?

IF CMDEXTVERSION 2 GOTO start_process

Does an error exist:

IF %ERRORLEVEL% EQU 2 goto sub_problem2