bash Cookbook

Getting Information About Files

Problem

You need more information about a file, such as what it is, who owns it, if it’s executable, how many hard links it has, or when it was last accessed or changed.

Solution

Use the ls, stat, file, or find commands.

$ touch /tmp/sample_file

$ ls /tmp/sample_file
/tmp/sample_file

$ ls -l /tmp/sample_file
-rw-r--r-- 1 jp         jp            0 Dec 18 15:03 /tmp/sample_file

$ stat /tmp/sample_file
File: "/tmp/sample_file"
Size: 0           Blocks: 0        IO Block: 4096   Regular File
Device: 303h/771d Inode:  2310201    Links: 1
Access: (0644/-rw-r--r--) Uid: (  501/      jp)   Gid: ( 501/        jp)
Access: Sun Dec 18 15:03:35 2005
Modify: Sun Dec 18 15:03:35 2005
Change: Sun Dec 18 15:03:42 2005

$ file /tmp/sample_file
/tmp/sample_file: empty

$ file -b /tmp/sample_file
empty

$ echo '#!/bin/bash -' > /tmp/sample_file

$ file /tmp/sample_file
/tmp/sample_file: Bourne-Again shell script text executable

$ file -b /tmp/sample_file
Bourne-Again shell script text executable

For much more on the find command, see all of Chapter 9.

Discussion

The command ls shows only filenames, while -l provides more details about each file. ls has many options; consult the manpage on your system for the ones it supports. Useful options include:ls

-a

Do not hide files starting with . (dot)

-F

Show the type of file with one of these trailing type designators: /*@%=|

-l

Long listing

-L

Show information about the linked file, rather than the symbolic link itself

-Q

Quote names (GNU extension, not supported on all systems)

-r

Reverse sort order ...