Bash Wildcards – Wildcard Not Expanding Hidden Files

bashwildcards

I'm trying to make a bash script that deals with every file in a directory. All of those file names begin with a dot, so they're hidden. When I try to use a wildcard to grab everything in the directory, the wildcard isn't expanding.

My code that loops over it looks like this right now:

#!/bin/bash
shopt -s extglob

for i in "$(pwd)"/*; do
  echo "$i"
done

The output is just /Users/.../*. The wildcard doesn't expand.

This is different than some of the other threads because it deals with hidden files specifically. If I add a file like test to the directory, then it works. I get /Users/.../test.

I tried running this in the terminal by itself as well and got the same result. How do I get the wildcard to expand for hidden files?

Best Answer

I figured it out! Looking more closely at the documentation for shopt, there's an option called dotglob that can be used to include filenames that begin with a dot!

I added shopt -s dotglob to the beginning of my script and it works now. The output now lists every hidden file and directory (except ./ and ../).

My script now looks like this:

#!/bin/bash
shopt -s extglob
shopt -s dotglob

for i in "$(pwd)"/*; do
  echo "$i"
done

Related Solutions

Bash globbing hidden files

You are mistaken. It means "a dot followed by exactly one non-dot followed by one character followed by zero or more characters". .a does not have enough characters to match it.

But really, just set dotglob.

Bash wildcard not expanding

A wildcard always expands to existing names.

Your command mkdir * fails because the names that * expands to already exists.

Your command mkdir *.d "fails" because the *.d does not match any existing names. The pattern is therefore left unexpanded by default¹ and a directory called *.d is created. You may remove this with rmdir '*.d'.

To create a directory for each regular file in the current directory, so that the new directories have the same name as the files, but with a .d suffix:

for name in ./*; do
    if [ -f "$name" ]; then
        # this is a regular file (or a symlink to one), create directory
        mkdir "$name.d"
    fi
done

or, for people that like "one-liners",

for n in ./*; do [ -f "$n" ] && mkdir "$n.d"; done

In bash, you could also do

names=( ./* )
mkdir "${names[@]/%/.d}"

but this makes no checks for whether the things that the glob expands to are regular files or something else.

The initial ./ in the commands above are to protect against filenames that contain an initial dash (-) in their filenames. The dash and the characters following it would otherwise be interpreted as options to mkdir.

¹ _{Some shells have a nullglob shell option that causes non-matched shell wildcards to be expanded to an empty string. In bash this is enabled using shopt -s nullglob.}

Best Answer

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Bash globbing hidden files

Bash wildcard not expanding

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