I'm trying to make the directories "01", "02", "03", ..., "11" and "12" in the current directory. But for an unknown reason my padding 'function' of "0" doesn't work within a for loop.
#Echo on
SET suffix=12
SET v=0%suffix%
SET v=%v:~-2%
echo %v%
pause
(SET suffix=12
SET v=0%suffix%
SET v=%v:~-2%
echo %v%)
pause
FOR /L %%q IN (9,1,11) DO (
SET suffixb=%%q
SET w=0%suffixb%
SET w=%w:~-2%
echo %w%
)
pause
In batch files, each line or block of lines (code inside parenthesis) is parsed, executed and the process repeated for the next line/block. During the parse phase, all variable reads are removed, being replaced with the value in the variable before the code starts to execute. If a variable changes its value inside the line/block, this changed value can not be retrieved from inside the same line/block as the variable read operation does not exist.
The usual way to solve it is to use delayed expansion. When enabled, you can change (where needed) the syntax from %var% to !var!, indicating to the parser that the read operation must be delayed until the command that uses the value starts to execute.
setlocal enabledelayedexpansion
for /l %%a in (101 1 112) do (
set "name=%%a"
md "!name:~-2!"
)
Related
I have an environment variable like this
set BINARY[0]=C:\binary.bin
From which I'm trying to extract the full file name
set "x=0"
:binloop
if defined BINARY[%x%] (
call echo %%BINARY[%x%]%%
FOR %%i IN ("%%BINARY[%x%]%%") DO (
set FNAME=%%~nxi
)
set /a "x+=1"
GOTO binloop
)
rem ...
However for some reason, it tries to do:
set FNAME=%BINARY[0]%
instead of
set FNAME=binary.bin
What's wrong with the code and why?
Open a command prompt window, run set /? and read the output help pages explaining when and how to use delayed expansion in a code block for the commands IF and FOR.
%% in a batch file is interpreted as literal percent character which is the reason why a loop variable in a command executed directly in a command prompt window must be specified with just one percent sign while the same loop in a batch file requires two percent signs on referencing the loop variable.
When the Windows command processor encounters an opening parenthesis which marks the beginning of a command block, it searches for the matching closing parenthesis and replaces all environment variables references with syntax %VariableName% by the current value of the variable or nothing in case of variable does not exist. Then after the entire command block was parsed the IF or FOR is executed and used is once or more times the already preprocessed command block.
You could use
#echo off
setlocal EnableExtensions EnableDelayedExpansion
set "BINARY[1]=C:\binary1.bin"
set "BINARY[0]=C:\binary0.bin"
set "x=0"
:binloop
if defined BINARY[%x%] (
call echo %%BINARY[%x%]%%
for %%i in ("!BINARY[%x%]!") do (
set FNAME=%%~nxi
set FNAME
)
set /a "x+=1"
goto binloop
)
endlocal
which outputs
C:\binary0.bin
FNAME=binary0.bin
C:\binary1.bin
FNAME=binary1.bin
The command line
call echo %%BINARY[%x%]%%
is something special. This line is preprocessed before execution of command IF to
call echo %BINARY[0]%
respectively on second run to
call echo %BINARY[1]%
By usage of command CALL the single command line is processed like a subroutine or another batch file which means the line is preprocessed once more resulting in execution of
echo C:\binary0.bin
and on second run in execution of
echo C:\binary1.bin
which is the reason why the output is as expected here. But there is no double preprocessing for the environment variable reference in FOR.
Much better would be most likely the following code:
#echo off
setlocal EnableExtensions EnableDelayedExpansion
set "BINARY[1]=C:\binary1.bin"
set "BINARY[0]=C:\binary0.bin"
for /F "tokens=1* delims==" %%I in ('set "BINARY[" 2^>nul') do (
set "FNAME=%%~nxJ"
set FNAME
)
endlocal
The command set outputs all variables with their name and equal sign and their values which start with the specified string when there is whether parameter /A or /P used and the parameter does not contain an equal sign in an alphabetically sorted list. So the output of
set "BINARY[" 2>nul
as used in the command FOR is
BINARY[0]=C:\binary0.bin
BINARY[1]=C:\binary1.bin
which is processed by the FOR loop which splits each line into two strings based on first occurrence of the equal sign because of tokens=1* delims==. The first string is the variable name assigned to loop variable I. And the second string is everything after first equal sign assigned to loop variable J being the next character in ASCII table.
2>nul is used to suppress the error message output by command SET to STDERR by redirecting it to device NUL if there is no environment variable defined with a name starting with BINARY[ in any case. The redirection operator > must be escaped with ^ as otherwise command processor would exit batch processing on this line because of 2>nul resulting in a syntax error on FOR command line at this position.
Note: Because of alphabetically sorted output by command SET the environment variable BINARY[10] is output after BINARY[0] and before BINARY[1] and BINARY[2]. So if the order is important, the first batch solution is needed or the environment variables are created with number in square brackets have all same number of digits with leading zeros, i.e. 00000, 00001, ..., 00002, 00010, 00011, ...
For understanding the used commands and how they work, open a command prompt window, execute there the following commands, and read entirely all help pages displayed for each command very carefully.
call /?
echo /?
endlocal /?
for /?
goto /?
if /?
set /?
setlocal /?
And see also Microsoft article about Using command redirection operators.
I've got a strange problem. I want to rename multiple files in a folder.
So far, so easy - in theory. I use this script:
cd C:\Test
for %%i in (*(7*) do (
set name="%%i"
ren "%name%" "%name:~0,-15%.txt"
)
pause
The strange thing is that he seems to not use the variable "name" I declared
one line above the ren command as you can see in what the console prints:
C:\Test>(
set name="ttttt(7xAAdoc) .txt"
ren "" "~0,-15.txt"
)
What am I missing here? I am running Windows 7, if thats important.
Thanks for any help.
Within a block statement (a parenthesised series of statements), the entire block is parsed and then executed. Any %var% within the block will be replaced by that variable's value at the time the block is parsed - before the block is executed - the same thing applies to a FOR ... DO (block).
Hence, IF (something) else (somethingelse) will be executed using the values of %variables% at the time the IF is encountered.
Two common ways to overcome this are 1) to use setlocal enabledelayedexpansion and use !var! in place of %var% to access the changed value of var or 2) to call a subroutine to perform further processing using the changed values.
In your case,
cd C:\Test
setlocal enabledelayedexpansion
for %%i in (*(7*) do (
set "name=%%i"
ren "%name%" "!name:~0,-15!.txt"
)
note the positioning of the quotes in the first set. The set "var=value" syntax ensures that any trailing spaces on the batch line are not included in the value assigned to var. As you had it, name would be assigned a "quoted" value and the ren command (had it worked) would have been `ren ""filename"" ""firstpartoffilename".txt"
I am using batch file to display some kind of number such as
00_test.txt 01_test.txt...10_test.txt 11_test.txt
Hence, This is my code. But I cannot show as my expectation
FOR /L %%x IN (1,1,10) DO (
set "extension=.txt"
set "fullname=%x%_test%extension%"
echo.%fullname%
)
The result of above code are _test.txt _test_txt but expected result are
00_test.txt 01_test.txt
Could you help me edit it?
#echo off
setlocal enabledelayedexpansion
set "baseName=_test"
set "extension=.txt"
for /l %%a in (1 1 10) do (
set "n=0%%a"
echo !n:~-2!%baseName%%extension%
)
When a block of code (in your case the for and the code inside parenthesis) is reached by the parser, all variable reads are replaced with the value in the variable before starting to execute the code. So, if a variable is changed inside the block and the value needs to be retrieved inside the same block, it is necessary to use delayed expansion, telling the parser that variables that are referenced as !var! (instead of %var%), should not be replaced at parse time, its value should be accessed at execution time.
So, in this code %baseName% and %extension% are used with usual syntax as its value does not change inside the for code block, but !n! uses delayed expansion. Its value changes inside the block and this value must be accessed inside the same block.
The concatenation of a 0 prefix and the extraction of two characters on the right from the variable ensure the presence of the initial 0 for values 1 to 9
Try %%x instead of %x:
FOR /L %%x IN (1,1,10) DO (
set "extension=.txt"
set "fullname=%%x%_test%extension%"
echo.%fullname%
)
The below code works, echo test.test
set replaceWith=.
set str="test\test"
call set str=%%str:\=%replaceWith%%%
echo %str%
But, the below code echo ggg.hhhhh all the 4 times.
SET SERVICE_LIST=(aaa\bbb ccc\dddd eeee\fffff ggg\hhhhh)
for %%i in %SERVICE_LIST% do (
set replaceWith=.
set str="%%i"
call set str=%%str:\=%replaceWith%%%
echo %str%
)
What am I doing wrong here?
If you understand why your code uses call set str=%%str:\=%replaceWith%%%, then you should be able to figure this out ;-)
Syntax like %var% is expanded when the line is parsed, and your entire parenthesized FOR loop is parsed in one pass. So %replaceWith% and echo %str% will use the values that existed before you entered your loop.
The CALL statement goes through an extra level of parsing for each iteration, but that only partially solves the issue.
The first time you ran the script, you probably just got "ECHO is on." (or off) 4 times. However, the value of str was probably ggghhhhh and replaceWith was . after the script finished. You don't have SETLOCAL, so when you run again, the values are now set before the loop starts. After the second time you run you probably got ggghhhhh 4 times. And then from then on, every time you run the script you get ggg.hhhhh 4 times.
You could get your desired result by using CALL with your ECHO statement, and moving the assignment of replaceWith before the loop.
#echo off
setlocal
SET SERVICE_LIST=(aaa\bbb ccc\dddd eeee\fffff ggg\hhhhh)
set "replaceWith=."
for %%i in %SERVICE_LIST% do (
set str="%%i"
call set str=%%str:\=%replaceWith%%%
call echo %%str%%
)
But there is a better way - delayed expansion
#echo off
setlocal enableDelayedExpansion
SET "SERVICE_LIST=aaa\bbb ccc\dddd eeee\fffff ggg\hhhhh"
set "replaceWith=."
for %%i in (%SERVICE_LIST%) do (
set str="%%i"
set str=!str:\=%replaceWith%!
echo !str!
)
Please have a text book for Windows Command Shell Script Language and try this:
#ECHO OFF &SETLOCAL
SET "SERVICE_LIST=(aaa\bbb ccc\dddd eeee\fffff ggg\hhhhh)"
for /f "delims=" %%i in ("%SERVICE_LIST%") do (
set "replaceWith=."
set "str=%%i"
SETLOCAL ENABLEDELAYEDEXPANSION
call set "str=%%str:\=!replaceWith!%%"
echo !str!
ENDLOCAL
)
This is my script:
#echo off
setlocal
for /f %%i in ('echo aaa/') do set REPO=%%i
if "%REPO%"=="" (
echo No input
) else (
echo %REPO:~-1%
echo %REPO:~0,-1%
if %REPO:~-1%==/ set REPO=%REPO:~0,-1%
echo %REPO%
)
endlocal
Please, observe:
c:\dev\shunra\GlobalLibrary\Server>c:\Utils\hgbackup.cmd
/
aaa
aaa/
c:\dev\shunra\GlobalLibrary\Server>
What is going on?
EDIT
Note, that I am assigning to REPO something that evaluates to "aaa", hence I expect it to print "aaa", not "aaa/". It drives me crazy.
EDIT2
Apparently, here is the culprit (from help on the set command):
Finally, support for delayed environment variable expansion has been
added. This support is always disabled by default, but may be
enabled/disabled via the /V command line switch to CMD.EXE. See CMD /?
Delayed environment variable expansion is useful for getting around
the limitations of the current expansion which happens when a line
of text is read, not when it is executed. The following example
demonstrates the problem with immediate variable expansion:
set VAR=before
if "%VAR%" == "before" (
set VAR=after
if "%VAR%" == "after" #echo If you see this, it worked
)
would never display the message, since the %VAR% in BOTH IF statements
is substituted when the first IF statement is read, since it logically
includes the body of the IF, which is a compound statement. So the
IF inside the compound statement is really comparing "before" with
"after" which will never be equal. Similarly, the following example
will not work as expected:
set LIST=
for %i in (*) do set LIST=%LIST% %i
echo %LIST%
in that it will NOT build up a list of files in the current directory,
but instead will just set the LIST variable to the last file found.
Again, this is because the %LIST% is expanded just once when the
FOR statement is read, and at that time the LIST variable is empty.
So the actual FOR loop we are executing is:
for %i in (*) do set LIST= %i
which just keeps setting LIST to the last file found.
Delayed environment variable expansion allows you to use a different
character (the exclamation mark) to expand environment variables at
execution time. If delayed variable expansion is enabled, the above
examples could be written as follows to work as intended:
set VAR=before
if "%VAR%" == "before" (
set VAR=after
if "!VAR!" == "after" #echo If you see this, it worked
)
set LIST=
for %i in (*) do set LIST=!LIST! %i
echo %LIST%
But I tried using the ! sign, still it does not work for me. I use get ! printed on the screen or the wrong result again.
As has been discussed in the comments, and in your edited question, you need delayed expansion.
Delayed expansion must be enabled before you can use it. Within a batch script you can use setlocal enableDelayedExpansion
#echo off
setlocal enableDelayedExpansion
for /f %%i in ('echo aaa/') do set REPO=%%i
if "%REPO%"=="" (
echo No input
) else (
echo %REPO:~-1%
echo %REPO:~0,-1%
if %REPO:~-1%==/ set REPO=%REPO:~0,-1%
echo !REPO!
)
endlocal
EDIT
The above fails if the IN() clause is changed such that REPO is undefined. For example: in (echo.)
It fails because the entire IF/ELSE construct must have valid syntax, even it the ELSE clause will not be executed.
If REPO is undefined, then
if %REPO:~-1%==/ set REPO=%REPO:~0,-1%
expands to
if ~-1REPO:~0,-1
which is invalid syntax.
The problem again is solved by using delayed expansion.
#echo off
setlocal enableDelayedExpansion
for /f %%i in ('echo.') do set REPO=%%i
if "%REPO%"=="" (
echo No input
) else (
echo %REPO:~-1%
echo %REPO:~0,-1%
if !REPO:~-1!==/ set REPO=%REPO:~0,-1%
echo !REPO!
)
endlocal
Note, that I am assigning to REPO something that evaluates to "aaa"
Actually, you're conditionally assigning something. Have you testing whether the then-part is actually executing (for example, echo If Entered).
This works for me (just an extract from my whole script)
choice /C 1234567H /M "Select an option or ctrl+C to cancel"
set _dpi=%ERRORLEVEL%
if "%_dpi%" == "8" call :helpme && goto menu
for /F "tokens=%_dpi%,*" %%1 in ("032 060 064 096 0C8 0FA 12C") do set _dpi=%%1
echo _dpi:%_dpi%: