Windows: copy a file until the file not exist - windows

Question

I want to use a Windows batch file in to copy a file (myfile0001.bdg) from one specific directory to another. But I want to check if the file in the target directory exists and if the answer is yes, increment the file with 0001 and check again if the file exists (myfile0002.bdg) and so on, until the file does not exist, and copy the file with the new title.
So, if in the target directory, I have these files:
myfile0001.bdg
myfile0002.bdg
myfile0003.bdg
myfile0004.bdg
myfile0005.bdg
myfile0006.bdg
The new file should be named myfile0007.bdg. The next time I will execute the batch, the new file will be myfile0008.bdg, etc.
I know there is a command "IF EXIST" but I don't know to do what I need.
==============
I'm under Windows 7 x32
The source directory is "C:\USERS\RAMBYTES\DOCUMENTS\"
The target directory is "P:\BACKUP\"
The file is "MYFILE0001.BDG"

Answer 1

Something like this:
#echo off
set source_file=C:\USERS\RAMBYTES\DOCUMENTS\MYFILE0001.BDG
set target_dir=P:\BACKUP\
set done=0
for /l %%i in (1,1,1000) do (
call :check_and_copy %%i
if errorlevel 1 goto :eof
)
goto :eof
:check_and_copy
setlocal EnableDelayedExpansion
set num=000000%1
set fnum=!num:~-4!
set fname=%target_dir%\myfile%fnum%.bdg
rem echo %fname%
if not exist "%fname%" (
echo copying %source_file% to %fname%
exit /b 1
)
exit /b 0
There is no error handling in case there are more than a 1000 files present in the target directory. If you want to increas the file limit, you need to adjust the "main" for loop and the "formatting" of the number in the sub-program
The trick with adding the leading zeros was taken from here: https://stackoverflow.com/a/9430912/330315

Answer 2

#ECHO OFF
SET destdir=c:\destdir
SET newname=myfile0000
FOR /f %%i IN (' dir /b /on %destdir%\myfile????.bdg ' ) DO SET newname=%%~ni
SET newname=1%newname:~-4%
SET /a newname+=1
SET newname=myfile%newname:~-4%.bdg
COPY myfile0001.bdg %destdir%\%newname%
change the destination directory as desired, and include the source directory if required.

Answer 3

Take the file name.
Extract the numeric part.
Check if the corresponding target name exists.
If so,
4.1) increase the numeric part;
4.2) if it doesn't exceed the highest possible number go to Step 3;
4.3) otherwise terminate.
If the target name doesn't exist, copy the file with the current numeric part and terminate.
Although algorithmically the condition in 4.2 may be more natural to be checked just after increasing the numeric part, like I put it above, the below script performs the check at a different point, at the beginning of the loop, which starts just after extracting the original numeric value from the source filename. Implementationally, that seemed to me more convenient.
In all other respects, the script implements the same algorithm:
#ECHO OFF
SET "fname=%~n1"
SET counter=1%fname:~-4%
:loop
IF %counter% GTR 19999 (
1>&2 ECHO Cannot copy the file: no free slots.
EXIT /B 1
)
SET "targetname=%~2\%fname:~0,-4%%counter:~1%%~x1"
IF EXIST "%targetname%" (
SET /A counter+=1
GOTO loop
) ELSE (
COPY %1 "%targetname%"
)
To explain some parts:
The tilde (~) in references to positional parameters means de-quoting of the correspondent parameter.
Sometimes in the script, the tilde is also directly followed by a modifier. Two modifiers are used here, n and x. The former causes the parameter to expand to the corresponding file name only (without the path and the extension) and the latter extract only the extension.
You can learn more about modifier in the built-in of the FOR command (by running
The fname environment variable is needed because extracting of name parts can only be done on environment variables. The %fname:~-4 expression, in particular, evaluates to the last four characters of the fname value. More specifically, it reads: extract the substring that starts at the 4th character from the end and, as -4 isn't followed by another argument, includes all the characters from that point till the end of the string.
Another similar-looking expression, %fname:~0,-4%, does the opposite: it returns the contents of fname except the last four characters. The meaning of the numbers is this: extract the substring that starts at the beginning of the string (offset 0) and spans the range up to and including the character at the offset of 4 from the end.
One more expression of this kind, %counter:~1, extracts the characters starting from the second one (i.e. offset 1) and up to the end of string (no second argument).
Run SET /? to find out more about string expressions.
The counter implementation may also require explanation. The 1 added in front of the numeric part of the file name is needed so that the entire value could be interpreted and processed correctly when incrementing it.
The thing is, a numeric value starting with a 0 is treated as an octal by the CMD command processor, so, putting 1 at the beginning makes it to interpret the number as a decimal, which it actually is. When constructing the complete name of the target file, we simply need to discard the added 1, which is what the %counter:~1 is used for.