C# Reserved Filenames

Reserved file names cannot be used. We can detect these names in strings in a C# program. This ensures we don't generate an invalid file name. Some reserved file names are CON.txt, PRN.doc and nul.exe.Path

Reserved filenames in Windows operating systems aux con clock$ nul prn com1 com2 com3 com4 com5 com6 com7 com8 com9 lpt1 lpt2 lpt3 lpt4 lpt5 lpt6 lpt7 lpt8 lpt9 Examples of reserved filenames aux.txt Con.bin NUL.png com2.png lpt8.aspx

Example. First, this problem can occur when a Windows server tries to serve a file such as PRN.aspx, which is dynamically generated. The file will not be available. I wrote this C# static class to detect such invalid file names.Static Class

Class that contains reserved names: C# using System.IO; /// <summary> /// Contains logic for detecting reserved file names. /// </summary> static class ReservedFileNameTool { /// <summary> /// Reserved file names in Windows. /// </summary> static string[] _reserved = new string[] { "con", "prn", "aux", "nul", "com1", "com2", "com3", "com4", "com5", "com6", "com7", "com8", "com9", "lpt1", "lpt2", "lpt3", "lpt4", "lpt5", "lpt6", "lpt7", "lpt8", "lpt9", "clock$" }; /// <summary> /// Determine if the path file name is reserved. /// </summary> public static bool IsReservedFileName(string path) { string fileName = Path.GetFileNameWithoutExtension(path); // Extension doesn't matter fileName = fileName.ToLower(); // Case-insensitive foreach (string reservedName in _reserved) { if (reservedName == fileName) { return true; } } return false; } /// <summary> /// Determine if the path file name is reserved. /// </summary> public static bool IsNotReservedFileName(string path) { return !IsReservedFileName(path); } }

You can save this static class in a file. We call its public static method IsReservedFileName to determine if a path has a reserved file name. In Windows, you are allowed to use the first letters in a reserved name as a file name.

But: There must be further letters. You are not allowed to use the reserved file names.

Summary. We saw a useful method. It can detect the invalid file names that Windows reserves. This includes Windows XP, Windows Vista, and all the Windows server environments, such as IIS 6.0 and IIS 7.0.

Note: This code could be sped up with a static Dictionary. But the performance difference isn't important in many cases.

Static Dictionary

The Dev Codes

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

Related Links

Adjectives Ado Ai Android Angular Antonyms Apache Articles Asp Autocad Automata Aws Azure Basic Binary Bitcoin Blockchain C Cassandra Change Coa Computer Control Cpp Create Creating C-Sharp Cyber Daa Data Dbms Deletion Devops Difference Discrete Es6 Ethical Examples Features Firebase Flutter Fs Git Go Hbase History Hive Hiveql How Html Idioms Insertion Installing Ios Java Joomla Js Kafka Kali Laravel Logical Machine Matlab Matrix Mongodb Mysql One Opencv Oracle Ordering Os Pandas Php Pig Pl Postgresql Powershell Prepositions Program Python React Ruby Scala Selecting Selenium Sentence Seo Sharepoint Software Spellings Spotting Spring Sql Sqlite Sqoop Svn Swift Synonyms Talend Testng Types Uml Unity Vbnet Verbal Webdriver What Wpf

TheDeveloperBlog.com

C# Reserved Filenames

Related Links:

.Net

Java

Related Links