file - Manipulate file names and attributes
file option name ?arg arg ...? _________________________________________________________________
provides several operations on a file’s name or
│ attributes. Name is the name of a
file; if it starts with a tilde, │ then
tilde substitution is done before executing the command (see
the │ manual entry for filename for
details). Option indicates what to do with the file
name. Any unique abbreviation for option is
acceptable. The valid options are:
file atime name
Returns a decimal string giving the time at which file name was last accessed. The time is measured in the standard POSIX fashion as seconds from a fixed starting time (often January 1, 1970). If the file doesn’t exist or its access time cannot be queried then an error is generated.
file dirname name
Returns a name comprised of all of the path components in name │ excluding the last element. If name is a relative file name and │ only contains one path element, then returns ’’.’’ (or ’’:’’ on │ the Macintosh). If name refers to a root directory, then the │ root directory is returned. For example, │
file dirname c:/ │
returns c:/. │
Note that tilde substitution will only be performed if it is │ necessary to complete the command. For example, │
file dirname ~/src/foo.c │
returns ~/src, whereas │
file dirname ~ │
returns /home (or something similar). │
file executable name
Returns 1 if file name is executable by the current user, 0 otherwise. Under UNIX this command uses the real user and group identifiers, not the effective ones.
file exists name
Returns 1 if file name exists and the current user has search privileges for the directories leading to it, 0 otherwise.
file extension name
Returns all of the characters in name after and including the last dot in the last element of name. If there is no dot in the last element of name then returns the empty string.
file isdirectory name
Returns 1 if file name is a directory, 0 otherwise.
file isfile name
Returns 1 if file name is a regular file, 0 otherwise.
file join name ?name ...? │
Takes one or more file names and combines them, using the │ correct path separator for the current platform. If a │ particular name is relative, then it will be joined to the │ previous file name argument. Otherwise, any earlier arguments │ will be discarded, and joining will proceed from the current │ argument. For example, │
file join a b /foo bar │
returns /foo/bar. │
Note that any of the names can contain separators, and that the │ result is always canonical for the current platform: / for Unix │ and Windows, and : for Macintosh. │
file lstat name varName
Same as stat option (see below) except uses the lstat kernel call instead of stat. This means that if name refers to a symbolic link the information returned in varName is for the link rather than the file it refers to. On systems that don’t support symbolic links this option behaves exactly the same as the stat option.
file mtime name
Returns a decimal string giving the time at which file name was last modified. The time is measured in the standard POSIX fashion as seconds from a fixed starting time (often January 1, 1970). If the file doesn’t exist or its modified time cannot be queried then an error is generated.
file owned name
Returns 1 if file name is owned by the current user, 0 otherwise.
file pathtype name │
Returns one of absolute, relative, volumerelative. If name │ refers to a specific file on a specific volume, the path type │ will be absolute. If name refers to a file relative to the │ current working directory, then the path type will be relative. │ If name refers to a file relative to the current working │ directory on a specified volume, or to a specific file on the │ current working volume, then the file type is volumerelative.
file readable name
Returns 1 if file name is readable by the current user, 0 otherwise. Under UNIX this command uses the real user and group identifiers, not the effective ones.
file readlink name
Returns the value of the symbolic link given by name (i.e. the name of the file it points to). If name isn’t a symbolic link or its value cannot be read, then an error is returned. On systems that don’t support symbolic links this option is undefined.
file rootname name
Returns all of the characters in name up to but not including the last ’’.’’ character in the last component of name. If the last component of name doesn’t contain a dot, then returns name.
file size name
Returns a decimal string giving the size of file name in bytes. If the file doesn’t exist or its size cannot be queried then an error is generated.
file split name │
Returns a list whose elements are the path components in name. │ The first element of the list will have the same path type as │ name. All other elements will be relative. Path separators │ will be discarded unless they are needed ensure that an element │ is unambiguously relative. For example, under Unix │
file split /foo/~bar/baz │
returns / foo ./~bar baz to ensure that later commands that │ use the third component do not attempt to perform tilde │ substitution. │
file stat name varName
Invokes the stat kernel call on name, and uses the variable given by varName to hold information returned from the kernel call. VarName is treated as an array variable, and the following elements of that variable are set: atime, ctime, dev, gid, ino, mode, mtime, nlink, size, type, uid. Each element except type is a decimal string with the value of the corresponding field from the stat return structure; see the manual entry for stat for details on the meanings of the values. The type element gives the type of the file in the same form returned by the command file type. This command returns an empty string.
file tail name
Returns all of the characters in name after the last directory │ separator. If name contains no separators then returns name.
file type name
Returns a string giving the type of file name, which will be one of file, directory, characterSpecial, blockSpecial, fifo, link, or socket.
file writable name
Returns 1 if file name is writable by the current user, 0 otherwise. Under UNIX this command uses the real user and group identifiers, not the effective ones.
attributes, directory, file, name, stat