Running a command on every file in a folder, then saving output - windows

Question

I am new to writing batch scripts and was hoping for some help.
I have a folder of images. I want to cURL each of these images, one by one, to an image classifier I made on the web. This will then send me a result.
I then want to save the response of the server into a file - let's keep it simple a say a CSV, in this format:
File, Response
So I know to run the Batch on each folder, I can do the following -
for /f %%f in ('dir /b c:\') do echo curl -X POST -F "images_file=#%%f" "https://gateway-a.watsonplatform.net/visual-recognition/api/v3/classify?api_key=abcdefgh&version=2016-05-20"*
I know, I can somehow pipe the results into an output file using ">>".
I don't know how to put this together, and how to create the CSV as I am running the batch script. Can anyone help? I think I am 90% there just new to batch scripting.

Answer 1

You can do something like this in powershell :
Change the placeholders as per your requirement.
$dir_files=Get-ChildItem "C:\"
foreach($file in $dir_files)
{
$result=Invoke-WebRequest 'https://gateway-a.watsonplatform.net/visual-recognition/api/v3/classify?api_key=abcdefgh&version=2016-05-20' -Method Post -Headers 'images_file=#%%f'
$result | ConvertTo-Csv | Out-File "D:\outputfile.csv" -Append -Force
}
I just gave you the way to set off. I didn't go through the complete batch code.
Hope it helps you.

Answer 2

If you want to use batch, you can do:
#echo
SetLocal EnableDelayedExpansion
set imagedir=C:\
set csvfile="C:\results.csv"
FOR %%G IN ("%imagedir%*") DO (
set resultfile=%%G.out
echo curl -X POST -F "images_file=#%%G" "https://gateway-a.watsonplatform.net/visual-recognition/api/v3/classify?api_key=abcdefgh&version=2016-05-20"* -o "!resultfile!"
echo %%G, !resultfile! >> %csvfile%
)
EndLocal
exit /b 0
I am not that experienced with curl so I'm not able to verify the correctness of your curl command and let the echo before it. But I do know that you can actually specify a file to write the output to in Windows with the -o flag.
The FOR command (without any flag/option) is another way to loop through files in a directory. If you still want to use the for /f %%f in ('dir /b ...') do-style (perhaps because of the order in which you want to treat your images), you can simply replace the line FOR %%G IN ("%imagedir%*") DO ( with for /f %%f in ('dir /b "%imagedir%"') DO (. I saved the directory in the variable imagedir, it's then easier to change. But if you change it, don't forget the \ at the end (if you use my for-command) and don't add double quotes (I add them in the FOR command). Be aware that this will treat all FILES in the directory. You can specify extensions if you want by using "%imagedir%\*.jpg" "%imagedir%\*.gif" for example for only GIF and JPEG images.
As last I'll say that I added SetLocal EnableDelayedExpansion to use delayed expansion. It's actually only needed because I saved the name of the file where the result of the curl operation will be saved, in the variable resultfile. In batch, a FOR -block (FOR ... ( ... )), and other blocks delimited with ( ) (as IF-blocks), are parsed as one single command (as if they were written on line). It is not really possible to change the value of a variable and read that new value in the same command (or same line) without using some special "tricks". Delayed expansion is one of them. When you use delayed expansion on a variable, you surround it with ! instead of %. As resultfile will change in each iteration, I use !resultfile! instead of %resultfile%.
If you don't want to save the name of the outputfile in a variable, you can remove the use of the variable and the delayed expansion (remove the EndLocal at the end too).
Good luck!