R: Extract File Information

file.info {base} | R Documentation

## Extract File Information

### Description

Utility function to extract information about files on the user's file systems.

### Usage

    file.info(...)

### Arguments

`...` | character vectors containing file paths. Tilde-expansion is done: see `path.expand`.

### Details

What constitutes a ‘file’ is OS-dependent but includes directories. (However, directory names must not include a trailing backslash or slash on Windows.) See also the section in the help for `file.exists` on case-insensitive file systems.

The file ‘mode’ follows POSIX conventions, giving three octal digits summarizing the permissions for the file owner, the owner's group and for anyone respectively. Each digit is the logical or of read (4), write (2) and execute/search (1) permissions.

On most systems symbolic links are followed, so information is given about the file to which the link points rather than about the link.

### Value

A data frame with row names the file names and columns

`size` | double: File size in bytes.
`isdir` | logical: Is the file a directory?
`mode` | integer of class `"octmode"`. The file permissions, printed in octal, for example `644`.
`mtime, ctime, atime` | integer of class `"POSIXct"`: file modification, ‘last status change’ and last access times.
`uid` | integer: the user ID of the file's owner.
`gid` | integer: the group ID of the file's group.
`uname` | character: `uid` interpreted as a user name.
`grname` | character: `gid` interpreted as a group name.

Unknown user and group names will be `NA`.

Entries for non-existent or non-readable files will be `NA`. The `uid`, `gid`, `uname` and `grname` columns may not be supplied on a non-POSIX Unix-alike system, and will not be on Windows.

What is meant by the three file times depends on the OS and file system. On Windows native file systems `ctime` is the file creation time (something which is not recorded on most Unix-alike file systems). What is meant by ‘file access’ and hence the ‘last access time’ is system-dependent.

The times are reported to an accuracy of seconds, and perhaps more on some systems. However, many file systems only record times in seconds, and some (e.g., modification time on FAT systems) are recorded in increments of 2 or more seconds.

### Note

Some systems allow files of more than 2Gb to be created but not accessed by the `stat` system call. Such files will show up as non-readable (and very likely not be readable by any of R's input functions) – fortunately such file systems are becoming rare.

### See Also

`Sys.readlink` to find out about symbolic links, `files`, `file.access`, `list.files`, and `DateTimeClasses` for the date formats.

`Sys.chmod` to change permissions.

### Examples

    ncol(finf <- file.info(dir()))  # at least six
    ## Not run: finf # the whole list
    ## Those that are more than 100 days old :
    finf[difftime(Sys.time(), finf[,"mtime"], units = "days") > 100 , 1:4]

    file.info("no-such-file-exists")

[Package base version 3.1.2 Index]