Filename

lastmod 2025-07-16created 2015-10-2715 edits

A filename is a special kind of string used to identify a file stored in a computer's file system. Depending on the operating system, such a name may also be recognized as a directory. Different operating systems may limit the length of filenames or disallow certain strings. Also, depending on the file system and operating system, filenames may or may not be case-sensitive. For example, old versions of MS-DOS supported only an 8-character name and a 3-character extension, but from MS-DOS 7.x onward, long filenames of 255 characters are supported.

About

A filename consists of the following.

• Protocol: access method (e.g. http, ftp, file)
• Host (network ID): host name, IP address, domain name, LAN network name (e.g. wikipedia.org, 207.142.131.206, \\MYCOMPUTER, SYS)
• Device (node): port, socket, drive, root mount point, disk, volume (e.g. C:, /, SYSLIB)
• File: base filename
• Type (format or extension): indicates the content type of the file (e.g. .txt, .exe, .dir)
• Version: version number of the file.

Terms

Wildcard character

A wildcard character is a symbol used to specify multiple files at once when issuing a command on a computer. The asterisk (*), question mark (?), and so on are used.

WINDOWS FILENAME

    /**
     * Characters prohibited in filename:
     *  0x00-0x1F, '"', '*', '*', '<', '>', '?', '\\' (single backslash), '/', '|'
     *
     * @remarks
     *  Many operating systems prohibit the ASCII control characters (0x00-0x1F) in filenames.
     */

File Rename script

• Batch File Rename with awk and sed
• awk and sed

$ ls foo*.jpg | awk '{print("mv "$1" "$1)}' | sed 's/foo/bar/2' | /bin/sh

See also

• UNC
• F2 - A CLI tool for batch-renaming files

Favorite site

• Wikipedia (en) description of filename (ko // comparison of filename restrictions)
• [Recommended] How to use long, beautiful path names on Windows ¹ (how to apply paths starting with \\?\ that exceed the MAX_PATH limit)
• [Recommended] [https://msdn.microsoft.com/ko-kr/library/windows/desktop/aa365247(v=vs.85.aspx MSDN: Naming Files, Paths, and Namespaces] ²

References