Unix illegal file name

Take another example of using digit and number together. The bash command implies running the code. We will get an error due to the usage of digits and numbers at the start. While correcting the variable, add the digit and number at the end of it and print it in an echo statement.

None of the special characters can be used in naming variables, e. Even though we put it before, after, or in the middle of the name of a variable, it will cause an error generation. This means that no special character can be used in the variable name before, after, and in between.

The underscore can be used in naming variables before, after, and in between. While trying it before, after, and between the name of a variable, it will cause an error generation. In the bash file, we have declared a variable with an underscore in between the variable name. The echo statement has been used to print the variable. Run the bash file using the bash command. You can see that the value has been printed out in the terminal correctly.

Linux file names: Forbidden characters? Sorry for a newbie question, but can anyone tell me what if any characters are forbidden in Linux file names?

Windows does not allow and of the following Also, anyone happen to know the case for the MacOS as well? November 3rd, , AM 2.

You will be fine as just about any Windows path will also be valid in Linux. As far as the Mac goes, if you are talking about Mac OSX, since it is UNIX-derived, the file name constraints are likely the same as for Linux although I don't know if there are additional constraints on file names placed by Apple.

September 28th, , PM 3. Community Bot 1 1 1 silver badge. Fred Gandt Fred Gandt 3, 1 1 gold badge 31 31 silver badges 39 39 bronze badges. Excellent advice! It's the same principle as storing names as name rather than trying to enforce first and last separately which makes me so mad. Or when I run into any restrictions on passwords other than minimum length. For what earthly reason!? Sometimes you have to let the user specify the actual file name for perfectly valid reasons.

Bombe Bombe That will wreak havoc sooner rather than later. Embedded quotes are tricky, too. Those are all non-issues when saving the filename. When using a graphical shell e. So what are your points? Bombe, what one user might want in many cases will alienate other users, regardless of the havoc it plays with your UI development process.

Bad idea. None of the standard tools of UNIX is badly written. What a short sighted answer from someone that really should know better. Your answer didn't even properly answer the original question. They say The name will not be difficult to manipulate later in terms of escaping special characters, etc. People have noted here that there are quite a few characters that can be in valid file names, but realistically cause a bunch of problems. Sign up or log in Sign up using Google.

Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Since the filename syntax also applies for directories, it is not possible to create a file and directory entries with the same name in a single directory. Multiple files in different directories may have the same name. This means two separate files might be created with the same text filename and a different byte implementation of the filename, such as L'x00C0.

Some filesystems, such as FAT, store filenames as upper-case regardless of the letter case used to create them. For example, a file created with the name 'MyName. Txt' or 'myname. Any variation of upper and lower case can be used to refer to the same file. These kinds of file systems are called case-insensitive and are not case-preserving.

Some filesystems prohibit the use of lower case letters in filenames altogether. Some file systems store filenames in the form that they were originally created; these are referred to as case-retentive or case-preserving. Such a file system can be case-sensitive or case-insensitive. If case-sensitive, then 'MyName. Txt' and 'myname. On a case-insensitive, case-preserving file system, on the other hand, only one of 'MyName.

Txt', 'myname. TXT' can be the name of a file in a given directory at a given time, and a file with one of these names can be referenced by any capitalization of the name. From its original inception, Unix and its derivative systems were case-preserving. Samba on most Unix-like systems , and SMB client file systems provide case-insensitive behavior. File system case sensitivity is a considerable challenge for software such as Samba and Wine, which must interoperate efficiently with both systems that treat uppercase and lowercase files as different and with systems that treat them the same.

File systems have not always provided the same character set for composing a filename. Before Unicode became a de facto standard, file systems mostly used a locale-dependent character set. By contrast, some new systems permit a filename to be composed of almost any character of the Unicode repertoire, and even some non-Unicode byte sequences.

Limitations may be imposed by the file system, operating system, application, or requirements for interoperability with other systems. Many file system utilities prohibit control characters from appearing in filenames.

File system utilities and naming conventions on Windows prohibit particular characters from appearing in filenames: [15]. In Windows utilities, the space and the period are not allowed as the final character of a filename. Workarounds include appending a dot when renaming the file that is then automatically removed afterwards , using alternative file managers, or saving a file with the desired filename from within an application.

Some file systems on a given operating system especially file systems originally implemented on other operating systems , and particular applications on that operating system, may apply further restrictions and interpretations. See comparison of file systems for more details on restrictions.

In addition, in Windows and DOS utilities, some words are also reserved and cannot be used as filenames. Systems that have these restrictions cause incompatibilities with some other filesystems. For example, Windows will fail to handle, or raise error reports for, these legal UNIX filenames: aux. NTFS allows each path component directory or filename to be characters long [ dubious ]. I need a comprehensive guide, however, and one that takes into accountdouble-byte characters.

Linking to outside resources is fine with me. I need to first create a directory on the filesystem using a name that maycontain forbidden characters, so I plan to replace those characters withunderscores. I then need to write this directory and its contents to a zip file using Java , so any additional advice concerning the names of zip directorieswould be appreciated. For example, spaces and dots are valid filename characters, but names composed only of those characters are forbidden.

Windows does not distinguish between upper-case and lower-case characters, so you cannot create a folder named A if one named a already exists.