Check Whether a Certain File Type/Extension Exists in Directory

Check whether a certain file type/extension exists in directory

#!/bin/bash

count=`ls -1 *.flac 2>/dev/null | wc -l`
if [ $count != 0 ]
then 
echo true
fi 

Check if a directory contains a file with a given extension

You can use the else block of the for:

for fname in os.listdir('.'):
    if fname.endswith('.true'):
        # do stuff on the file
        break
else:
    # do stuff if a file .true doesn't exist.

The else attached to a for will be run whenever the break inside the loop is not executed. If you think a for loop as a way to search something, then break tells whether you have found that something. The else is run when you didn't found what you were searching for.

Alternatively:

if not any(fname.endswith('.true') for fname in os.listdir('.')):
    # do stuff if a file .true doesn't exist

---

Moreover you could use the glob module instead of listdir:

import glob
# stuff
if not glob.glob('*.true')`:
    # do stuff if no file ending in .true exists

How can I check if a certain file type exists in a directory?

You could do something like

Dir['some_dir/*.exe'].any?

With subfolders

Dir['some_dir/**/*.exe'].any?

check if file with certain file extension present in folder using batch script

In the simplest case the batch language includes a construct for this task

if exist *.elf (
    :: file exists - do something 
) else (
    :: file does not exist - do something else
)

where the if exist will test for existence of an element in the current or indicate folder that matches the indicated name/wildcard expression.

While in this case it seems you will not need anything else, you should take into consideration that if exist makes no difference between a file and a folder. If the name/wildcard expression that you are using matches a folder name, if exists will evaluate to true.

How to ensure we are testing for a file? The easiest solution is to use the dir command to search for files (excluding folders). If it fails (raises errorlevel), there are no files matching the condition.

dir /a-d *.elf >nul 2>&1 
if errorlevel 1 (
    :: file does not exist - do something
) else (
    :: file exists - do something else
)

Or, using conditional execution (just a little abreviation for the above code)

dir /a-d *.elf >nul 2>&1 && (
    :: file does exist - do something
) || ( 
    :: file does not exist - do something else 
)

What it does is execute a dir command searching for *.elf , excluding folders (/a-d) and sending all the output to nul device, that is, discarding the output. If errorlevel is raised, no matching file has been found.

How to check if a directory contains a certain file type?

If you just want to check the count of .txt files is 0 then you could use glob.glob() instead:

import glob

if len(glob.glob("*.txt")) == 0:
    print "No TXT files"

Checking if file with file-extension '.ini' exists, shell

set -- /dir/*.ini
case $1 in
  ('/dir/*.ini') echo "No ini files here.";;
  (*)            echo "Found $# ini files: $@";;
esac

Look ma! No forks! This should beat, by a million of CPU cycles, any solution with forks to ls, find and friends.

Now there's one little gotcha here. Can you spot it? Okay, what happens if /dir contains a file named *.ini literally (star, dot, ini)? The above will give you a false negative: it reports no ini file although there is one. If you want to prepare for this case (and you should, because you are a careful programmer, giving attention to detail, no gotchas in your code, right?), you slightly modify the first case to read

('/dir/*.ini')
  if test -f '/dir/*.ini'; then
    echo "Wow, there's a plain file named '/dir/*.ini'!"
  else
    echo "No ini files here."
  fi;;

how to check if a specific file extension exists in a folder using powershell?

Try this:

function Get-ExtensionCount {
    param(
        $Root = "C:\Root\",
        $FileType = @(".sln", ".designer.vb"),
        $Outfile = "C:\Root\rootext.txt"
    )

    $output = @()

    Foreach ($type in $FileType) {
        $files = Get-ChildItem $Root -Filter *$type -Recurse | ? { !$_.PSIsContainer }
        $output += "$type ---> $($files.Count) files"
        foreach ($file in $files) {
            $output += $file.FullName
        }
    }

    $output | Set-Content $Outfile
}

I turned it into a function with your values as default parameter-values. Call it by using

Get-ExtensionCount    #for default values

Or

Get-ExtensionCount -Root "d:\test" -FileType ".txt", ".bmp" -Outfile "D:\output.txt"

Output saved to the file ex:

.txt ---> 3 files
D:\Test\as.txt
D:\Test\ddddd.txt
D:\Test\sss.txt
.bmp ---> 2 files
D:\Test\dsadsa.bmp
D:\Test\New Bitmap Image.bmp

To get the all the filecounts at the start, try:

function Get-ExtensionCount {
    param(
        $Root = "C:\Root\",
        $FileType = @(".sln", ".designer.vb"),
        $Outfile = "C:\Root\rootext.txt"
    )
    #Filecount per type
    $header = @()
    #All the filepaths    
    $filelist = @()

    Foreach ($type in $FileType) {
        $files = Get-ChildItem $Root -Filter *$type -Recurse | ? { !$_.PSIsContainer }
        $header += "$type ---> $($files.Count) files"
        foreach ($file in $files) {
            $filelist += $file.FullName
        }
    }
    #Collect to single output
    $output = @($header, $filelist)    
    $output | Set-Content $Outfile
}

Is there an R function for checking if files with a certain extension exist in a path?

Using base R:

list.files(path = "pathname", pattern = "\\.csv$")

will return a vector of strings with the filenames that end in ".csv". To check if any exist, use:

length(list.files(path = "pathname", pattern = "\\.csv$")) > 0

How can I Check whether file exists with a specific extension in a folder

The below code may help you.

public class FindCertainExtension {

    private static final String FILE_DIR = "c:\\folder";
    private static final String FILE_TEXT_EXT = ".jpg";

    public static void main(String args[]) {
        new FindCertainExtension().listFile(FILE_DIR, FILE_TEXT_EXT);
    }

    public void listFile(String folder, String ext) {

        GenericExtFilter filter = new GenericExtFilter(ext);

        File dir = new File(folder);

        if(dir.isDirectory()==false){
            System.out.println("Directory does not exists : " + FILE_DIR);
            return;
        }

        // list out all the file name and filter by the extension
        String[] list = dir.list(filter);

        if (list.length == 0) {
            System.out.println("no files end with : " + ext);
            return;
        }

        for (String file : list) {
            String temp = new StringBuffer(FILE_DIR).append(File.separator)
                    .append(file).toString();
            System.out.println("file : " + temp);
        }
    }

    // inner class, generic extension filter
    public class GenericExtFilter implements FilenameFilter {

        private String ext;

        public GenericExtFilter(String ext) {
            this.ext = ext;
        }

        public boolean accept(File dir, String name) {
            return (name.endsWith(ext));
        }
    }
}

Enjoy !!!

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