{"id":39,"date":"2024-12-13T07:07:54","date_gmt":"2024-12-13T07:07:54","guid":{"rendered":"https:\/\/techkubo.com\/linux\/?p=39"},"modified":"2025-05-28T17:51:07","modified_gmt":"2025-05-28T17:51:07","slug":"linux-file-command","status":"publish","type":"post","link":"https:\/\/techkubo.com\/linux\/linux-file-command\/","title":{"rendered":"Linux – file Command"},"content":{"rendered":"\n

The file<\/code> command is used to determine the type of a file. It examines the file’s content and provides information about its format, such as whether it is a text file, a binary executable, or an image file. This command is useful for understanding the nature of files, especially when their extensions are not indicative of their content.<\/p>\n\n\n\n

Initial Example<\/h2>\n\n\n\n

Using file<\/code> to determine the type of a file called example.txt<\/code>:<\/p>\n\n\n\n

file example.txt<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
FILE Parameters<\/h2>\n\n\n\n
Parameter<\/th>Description<\/th><\/tr><\/thead>
--apple<\/code><\/td>Output the file type and creator code as used by older MacOS versions<\/td><\/tr>
-b, --brief<\/code><\/td>Suppress filenames in the output for a cleaner, brief format<\/td><\/tr>
-C, --compile<\/code><\/td>Generate a pre-parsed magic.mgc file from the magic file or directory<\/td><\/tr>
-c, --checking-printout<\/code><\/td>Print the parsed form of the magic file for debugging purposes<\/td><\/tr>
-d<\/code><\/td>Print internal debugging information to stderr<\/td><\/tr>
-E<\/code><\/td>Exit on filesystem errors, like file not found, instead of continuing<\/td><\/tr>
-e, --exclude testname<\/code><\/td>Exclude specified tests from determining the file type (e.g., ascii<\/code>, compress<\/code>, json<\/code>)<\/td><\/tr>
--exclude-quiet<\/code><\/td>Ignore unknown tests specified in the exclude list, for compatibility with older versions<\/td><\/tr>
--extension<\/code><\/td>Display valid file extensions for the identified file type<\/td><\/tr>
-F, --separator<\/code><\/td>Use a custom string as a separator between filename and file type in the output<\/td><\/tr>
-f, --files-from<\/code><\/td>Read file names to be examined from the specified file, one per line<\/td><\/tr>
-h, --no-dereference<\/code><\/td>Do not follow symbolic links (affect the symlink itself)<\/td><\/tr>
-i, --mime<\/code><\/td>Output MIME type strings instead of human-readable file types<\/td><\/tr>
--mime-type<\/code><\/td>Output only the MIME type of the file<\/td><\/tr>
--mime-encoding<\/code><\/td>Output only the MIME encoding of the file<\/td><\/tr>
-k, --keep-going<\/code><\/td>Continue checking for additional matches after the first match<\/td><\/tr>
-l, --list<\/code><\/td>List all patterns and their strength sorted by matching strength<\/td><\/tr>
-L, --dereference<\/code><\/td>Follow symbolic links to the actual file<\/td><\/tr>
-m, --magic-file<\/code><\/td>Specify an alternate file or directory containing magic definitions<\/td><\/tr>
-N, --no-pad<\/code><\/td>Do not pad filenames to align them in the output<\/td><\/tr>
-n, --no-buffer<\/code><\/td>Flush stdout after checking each file for real-time output<\/td><\/tr>
-p, --preserve-date<\/code><\/td>Preserve the access time of files during analysis<\/td><\/tr>
-P, --parameter<\/code><\/td>Set various limits for file processing parameters, like maximum bytes to read, recursion limits<\/td><\/tr>
-r, --raw<\/code><\/td>Do not translate unprintable characters to octal representation<\/td><\/tr>
-s, --special-files<\/code><\/td>Also read and determine the type of special files (block, character devices, pipes, etc.)<\/td><\/tr>
-S, --no-sandbox<\/code><\/td>Disable sandboxing to allow the execution of external decompressing programs<\/td><\/tr>
-v, --version<\/code><\/td>Display version information and exit<\/td><\/tr>
-z, --uncompress<\/code><\/td>Attempt to look inside compressed files<\/td><\/tr>
-Z, --uncompress-noreport<\/code><\/td>Look inside compressed files but report only the contents, not the compression method<\/td><\/tr>
-0, --print0<\/code><\/td>Output a null character (\\0<\/code>) after each filename for compatibility with tools like cut<\/code><\/td><\/tr>
--help<\/code><\/td>Display help information and exit<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
Examples<\/h2>\n\n\n\n
1. Determine the Type of a Single File<\/h4>\n\n\n\n
To identify the type of a specific file:<\/p>\n\n\n\n
file filename.txt<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
2. Determine the Type of Multiple Files<\/h4>\n\n\n\n
To identify the types of multiple files at once, specify their names separated by spaces:<\/p>\n\n\n\n
file file1.txt file2.jpg file3.pdf<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
3. Determine the Type of All Files in a Directory<\/h4>\n\n\n\n
To identify the types of all files in a directory, use a wildcard (*<\/code>):<\/p>\n\n\n\n
file \/path\/to\/directory\/*<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
4. Verbose Output<\/h4>\n\n\n\n
To display more detailed information about the file type, use the -v<\/code> (verbose) option:<\/p>\n\n\n\n
file -v example.txt<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
5. Follow Symbolic Links<\/h4>\n\n\n\n
To follow symbolic links and determine the type of the target file, use the -L<\/code> option:<\/p>\n\n\n\n
file -L symbolic_link<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
Linux Playground<\/h2>\n\n\n\n