The following conventions apply to file names:
You may use any character with the exception of / and \0 (zero bytes terminating a character string).
You should not enter the characters plus (+), minus (-) or period (.) at the beginning of a file name. The period is reserved for special files, e.g. for the file .profile.
Example of the use of a file name beginning with the minus sign (-):
touch -- -file1(before the file name is entered, the (void) options must be terminated)
For more information on the use of the characters *, ?, [...], see the section “File name generation”.
You should not use a number of special characters (see the chapter “Tables and directories”).
If the filename contains spaces or tabs you must place it inside quotes.
Unlike BS2000, POSIX distinguishes between uppercase and lowercase in file names.
There are two ways of specifying the names of files and directories in the POSIX shell:
You can specify a relative path name. Relative path names always start from the current directory.
You can specify an absolute path name. Absolute path names start with a slash (/) and specify the name relative to the root directory.
A file name must not exceed 1024 characters in length. This limit includes the directory names, the name of the file itself and the slashes which are used as separators.