Windows batch version of Unix select command? - bash

Question

I'm trying to create a Windows version of a simple bash script I have, but I cannot seem to find a Windows version of the Unix 'select' command. Is there one?
Here's the script:
#!/bin/bash
echo "Enter the number of the file you want to select:"
select THE_FILE in someDir/*;
do
echo "You picked $THE_FILE ($REPLY)"
# Will do some stuff here.
break;
done
It was very easy to find this Linux example, so I am a bit perplexed that I cannot seem to find a Windows equivalent.
Edit: The select command prompts the user to select a file from a given directory (that's an oversimplification). To clarify, the script from above will produce the following output, assuming there is a subdirectory 'someDir' with only those three text files in it.
Enter the number of the file you want to select:
1) someDir/somefile1.txt
2) someDir/somefile2.txt
3) someDir/somefile3.txt
#? 2
You picked someDir/somefile2.txt (2)

Answer 1

Windows batch commands does not include any equivalent to the select command. So you will have to build your own version.
You will need:
call command. Create a subroutine and reuse it
for command to iterate over the files, or for /f to iterate over the output of another command returning the list of files
For short lists, choice command is more friendly to the user as it is not needed to press enter, but for longer lists or if you don't know the number of files to select, set /p is a better option
Here, just a sample
#echo off
setlocal enableextensions disabledelayedexpansion
call :select "someDir\*" THE_FILE
echo You picked %THE_FILE%
goto :eof
:select mask returnVar
setlocal enableextensions disabledelayedexpansion
rem Configure internal variables
set "fileNumber="
set "maxFiles=-1"
for /f "delims==" %%a in ('2^>nul set f[') do set "%%a="
echo Enter the number of the file you want to select:
rem Search files, show list and create array with file list
rem Using xcopy to get the list of files because it will show
rem relative paths when a relative mask is used as input
for /f "tokens=1,* delims=:" %%a in ('
xcopy "%~1" "%temp%" /l ^| findstr /n /r /c:"[\\\.:]"
') do (
echo %%a^) %%b
set "f[%%a]=%%~fb"
set "maxFiles=%%a"
)
rem Prompt
:select.ask
set /p "fileNumber=#? "
rem Validate input
set /a "fileNumber=fileNumber+0" 2>nul
if %fileNumber% gtr %maxFiles% set "fileNumber=-1"
if %fileNumber% lss 1 set "fileNumber="
if not defined fileNumber (
echo Wrong selection
goto :select.ask
)
rem Retrieve file from array
setlocal enabledelayedexpansion
for %%a in ("!f[%fileNumber%]!") do (
endlocal
set "selectedFile=%%~a"
)
rem Return selection to caller
endlocal & set "%~2=%selectedFile%"
goto :eof

Answer 2

See Choice /? or set /?.
choice /c:yn
If errorelevel 1 if not errorlevel 2 echo Y was chosen

Answer 3

Although a bash select equivalent is not included in Windows Batch, it is very easy to write your own. It may be a subroutine with the exact same parameters of Linux select so you don't need to learn something new in order to use it; this way, the "in" word in second parameter will not be used in the Batch code.
#echo off
call :select THE_FILE in someDir/*
echo You picked %THE_FILE% (%errorlevel%)
goto :EOF
rem Subroutine that emulates Linux's select
:select returnVar in directory
setlocal EnableDelayedExpansion
echo Enter the number of the file you want to select:
rem Show the files and create an array with them
set n=0
for %%a in (%3) do (
set /A n+=1
set file[!n!]=%%a
echo !n!^) %%a
)
rem Get the number of the desired file
:getNumber
set /P "number=#? "
if not defined file[%number%] goto getNumber
rem Return selected file to caller
for /F "delims=" %%a in ("!file[%number%]!") do endlocal & set "%1=%%a" & exit /B %number%
Previous code is straigthforward, but post a comment here if you have any doubt about it. Perhaps the most complex part is the for /F command at last line, that is required to save the value of the !filename[%number%]! in the %%a FOR parameter before execute the endlocal and the assignment to the first parameter, that is the way to return that value to the calling program. If endlocal would be executed first, the !delayed expansion! of the variable will no longer work...
Although this code does not return the path of the selected file, it is very easy to add such feature, but the code will complicate a little.

Answer 4

While a batch-file solution is desired by the OP, it is worth presenting a PowerShell solution that is much more concise:
($files = get-childitem -file someDir\) | % { $i=0 } { ++$i; "$i) $_" }
$reply = read-host -p "Enter the number of the file you want to select"
"You picked $($files[$reply-1]) ($reply)"
$files = get-childitem -file someDir\ collects all files in directory someDir in variable $files
Note that the -file option for restricting child items to files requires PowerShell 3.0 or higher; on earlier versions, pipe to ? { -not $_.PSIsContainer } instead.
% { $i=0 } { ++$i; "$i) $_" } outputs each filename prefixed with its 1-based index.
% is shorthand for the ForEach-Object object cmdlet, which processes a block of code for each input object
{ $i=0 } initializes the index variable (executed once, before iteration)
{ ++$i; "$i) $_" } is executed for each input object, $_; ++$i increments the index, "$i) $_" prints the index followed by ) and a space, followed by the input object's default property, which is the filename in this case. (If you wanted to print the full path instead, for instance, you'd use "$i) $($_.fullname)").
Note how no explicit output (print) command is needed - the results are output to the terminal by default.
$reply = read-host -p "Enter the number of the file you want to select" reads a single line from the terminal with the specified prompt and stores the user's input in variable $reply.
"You picked $($files[$reply-1]) ($reply)" outputs the result; again, no explicit output command is required.