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My task was to print the number of files in the current directory without using ls and wc commands.

I had typed the following lines in the script:

#!/bin/bash
find . -maxdepth 1 -type f \( ! -iname ".*" \) > list3
grep .* -c list3 > /dev/tty

The output is:

..:0
.6.1c.sh.swp:1
list3:22

while according to my understanding it should only be: 22

Why doesn't that work?

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2 Answers 2

Why grep isn't working correctly

It doesn't work because you need to tell grep that .* is the actual pattern you're looking for.

grep '.*' -c list3

If you don't use the single quotes, your shell will expand .* to the names of every file in your directory. This is called Filename Expansion. For example a.txt b.txt, so grep will see:

grep a.txt b.txt -c list3

Since single quotes prevent expansion from happening, this is the way to go here.


Where your grep command is wrong:

By the way, you're going the wrong direction with the pattern here. The period . in a regular expression matches any character, and not the literal dot. See the man page for more info. So your regex currently says: "find any character and then a sequence of any character". Quite redundant.

If you actually mean to match:

[dot] [anything else]

… you need to escape the dot:

\.*

Where your find command could be improved:

I don't know what you mean to get rid of by

\( ! -iname ".*" \)

Your find command will prefix any file with the dot for the current working directory, thus you won't remove anything here. You could have just run:

find . -maxdepth 1 -type f
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To address the original problem, counting files without ls and wc:

Pure shell syntax:

files=0
for i in *; do
    [ -f "${i}" ] && files=$((files+1))
done
echo ${files}

To add hidden files to the count, just change the globbing settings prior to the for loop.

Alternatively: fun with find and shell expansion:

echo $(($(find -maxdepth 1 -type f -printf '+1')))
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