File Exists by File Name Pattern

file exists by file name pattern

You can do a directory list with a pattern to check for files

string[] files = System.IO.Directory.GetFiles(path, "*_peach.xml", System.IO.SearchOption.TopDirectoryOnly);
if (files.Length > 0)
{
    //file exist
}

check if file exists with a partial name in C

This is impossible in portable C because the C Standard Library does not have an API for enumerating files in a directory (then matching them yourself) let alone an API for matching file names by a pattern. This is because C predates modern notions of hierarchical directories (even the original Macintosh in 1984 didn't support subdirectories) - and because C still supports those systems today (think: microcontrollers).

In practice, you'd use your platform's filesystem API: on Unix-like/POSX systems including Linux that's done with dirent.h - and for your problem specifically you'd use the glob function: http://pubs.opengroup.org/onlinepubs/009604499/basedefs/glob.h.html

glob_t result;
const int ok = glob( "/tmp/God_of_War*", /*flags:*/ 0, /*errfunc:*/ NULL, &result );
if( 0 == ok ) {
    for( size_t i = 0; i < result.gl_pathc; i++ ) {
        puts( result.gl_pathv[i] );
    }
}
else {
    // error
}
globfree( &result);

On Windows, that's FindFirstFile and FindNextFile which you can use wildcards with, just like glob.

WIN32_FIND_DATA result;
HANDLE searchHandle = FindFirstFile( "God_of_War*", &result);
if( searchHandle == INVALID_HANDLE_VALUE ) {
    // handle error, use GetLastError() for details
}
else {
    do {
        puts( searchHandle.cFileName );
    }
    while( FindNextFile( searchHandle, &searchHandle ) );
    DWORD lastError = GetLastError();
    if( lastError != ERROR_NO_MORE_FILES ) {
        // handle error
    }
}

Check if filename matches particular pattern or not

Your can try with regular expressions:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Text.RegularExpressions;
namespace ConsoleAppRegex
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] fileNames = new string[] { "genprice20212604.xml",
                                                "genprice20212704.xml",
                                                "price20212604.xml",
                                                "genprice20212704.txt"}; 
            Regex re = new Regex(@"genprice[^\.]*.xml");

            foreach (string fileName in fileNames)
            {
                if (re.Match(fileName).Success)
                {
                    Console.WriteLine(fileName);
                }
            }
            Console.ReadLine();
        }
    }
}

Check if a file matching a pattern exists

First make sure you have a File object pointing to the directory where this file might need to be created. After that, you can call listFiles(FilenameFilter filter) on it. If it returns an array that is not of length 0, it means at least one file with a partial match for the name exists. You could additionally use this to detect incorrect situations (e.g. an array of length greater than 1 means there's too many files with that portion of the name).

To use this, you'd have to create an implementation of FilenameFilter. Make sure it has a constructor in which you pass the partial name or pattern for which you need to check. Regular expressions might not be necessary, a simple check to see if the current date in the desired format is contained in the file name would suffice.

Alternatively, you could use listFiles(FileFilter filter) with an implementation of FileFilter instead of FilenameFilter if there might be directories with dates in their names. Getting a single File instance for checking instead of a File for the directory plus a file name can make this easier, using method isDirectory() of File.

In C, checking for existence of file with name matching a pattern

You can use glob(3) (standardized by POSIX). You give it a wildcard pattern and it will search the filesystem for matches.

Example:

#include <glob.h>
#include <stdio.h>

int main(int argc, char **argv)
{
   glob_t globbuf;
   if (0==glob(argv[1], 0, NULL, &globbuf)){
       char **a=globbuf.gl_pathv;

       puts("MATCHES");
       for(;*a;a++)
           puts(*a);
   }
   globfree(&globbuf);
}

Running:

./a.out 'lockfile*'

should give you your lockfiles.

Check if file exists based on partial file name in Java

This code should help you.

First list out all the files in the folder

Start a loop and then get the fileName for each file and start
comparing the name to do your job.

String folderName = "."; // Give your folderName
File[] listFiles = new File(folderName).listFiles();

for (int i = 0; i < listFiles.length; i++) {

    if (listFiles[i].isFile()) {
        String fileName = listFiles[i].getName();
        if (fileName.startsWith("MyTextFile_")
                && fileName.endsWith(".txt")) {
            System.out.println("found file" + " " + fileName);
        }
    }
}

How can I check if a file exists with a certain string in its filename?

Sounds like you need the glob() function. The glob() function searches for all the pathnames matching pattern according to the rules used by the libc glob() function, which is similar to the rules used by common shells.

<?php
foreach (glob('1_*.*') as $filename) {
    echo "$filename\n";
}
?>

The above example will output something similar to:

1_foo.png
1_bar.png
1_something.png

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