Csdrhrt

On my Linux machine, I can use the file command to list the contents of a directory by using it this way:

file /home/user/*

It prints the file type for each file in the /home/user/ directory. This way, I can get to know the list of all the files in that directory.

However, on a remote Linux machine, I am not able to use the wild card character with file command.

file /home/user/*

/home/user/*: cannot open `/home/user/*' (No such file or directory)

Does file command not support wild card characters on certain versions of Linux? Or is this is a restriction?

Thanks.

The file utility doesn't handle wildcards, the shell does...

The shell is likely bash or dash or sh, or something similar - you can run echo $0 at a prompt to see what's running.

As mentioned above, the wildcards are handled by the shell (not the application), and the expansion's default behaviour might be a little unexpected. Bash, for example, will use the following behaviour:

• If /home/user either doesn't exist, or has nothing in it, then /home/user/* will not expand, but will remain as-is (i.e: /home/user/*).


• If /home/user is a directory with two files a and b in it, then /home/user/* will expand to /home/user/a /home/user/b.

With bash, you can:

• Disable "globbing" entirely by running set -f, or


• Expand a "glob" to nothing if it doesn't match anything by running shopt -s nullglob.

This means that either:

• The remote shell doesn't support globbing at all


• The remote shell has globbing disabled by default (try running set +f to enable it)

If your end goal really is to "run find on all entities in /home/user/", then you could try the following:

find /home/user/ -maxdepth 1 -type f -print0 

    | xargs -0 file

• 
  -maxdepth 1 prevents recursion


• 
  -type f shows only files (not directories, symlinks, etc...)


• 
  find's -print0 and xargs' -0 arguments are used together to use a NUL character () to separate entries, as special characters line newline (n) are valid in filenames.


• 
  xargs will use records provided via stdin, and use them as additional parameters to the specified command (file in this case)

Default (set +f / shopt -u nullglob)

$ tree

.

└── x



1 directory, 0 files

$ echo glob x/*

glob x/*

$ touch x/a x/b

$ tree

.

└── x

    ├── a

    └── b

$ echo glob x/*

glob x/a x/b

No Globbing (set -f / shopt -u nullglob)

$ tree

.

└── x



1 directory, 0 files

$ echo glob x/*

glob x/*

$ touch x/a x/b

$ tree

.

└── x

    ├── a

    └── b

$ echo glob x/*

glob x/*

Null Glob Expansion (set +f / shopt -s nullglob)

$ tree

.

└── x



1 directory, 0 files

$ echo glob x/*

glob 

$ touch x/a x/b

$ tree

.

└── x

    ├── a

    └── b

$ echo glob x/*

glob x/a x/b