How do I find files that do not contain a given string pattern?

You can do it with grep alone (without find).

grep -riL "foo" .

This is the explanation of the parameters used on grep

     -L, --files-without-match
             each file processed.
     -R, -r, --recursive
             Recursively search subdirectories listed.

     -i, --ignore-case
             Perform case insensitive matching.

If you use l (lowercased) you will get the opposite (files with matches)

     -l, --files-with-matches
             Only the names of files containing selected lines are written

If you are using git, this searches all of the tracked files:

git grep -L "foo"

and you can search in a subset of tracked files if you have ** subdirectory globbing turned on (shopt -s globstar in .bashrc, see this):

git grep -L "foo" -- **/*.cpp

I had good luck with

grep -H -E -o -c "foo" */*/*.ext | grep ext:0

My attempts with grep -v just gave me all the lines without "foo".

Problem

I need to refactor a large project which uses .phtml files to write out HTML using inline PHP code. I want to use Mustache templates instead. I want to find any .phtml giles which do not contain the string new Mustache as these still need to be rewritten.

Solution

find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$ | sed 's/..$//'

Explanation

Before the pipes:

Find

find . Find files recursively, starting in this directory

-iname '*.phtml' Filename must contain .phtml (the i makes it case-insensitive)

-exec 'grep -H -E -o -c 'new Mustache' {}' Run the grep command on each of the matched paths

Grep

-H Always print filename headers with output lines.

-E Interpret pattern as an extended regular expression (i.e. force grep to behave as egrep).

-o Prints only the matching part of the lines.

-c Only a count of selected lines is written to standard output.

This will give me a list of all file paths ending in .phtml, with a count of the number of times the string new Mustache occurs in each of them.

$> find . -iname '*.phtml$' -exec 'grep -H -E -o -c 'new Mustache' {}'\;

./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml:0
./app/MyApp/Customer/View/Account/studio.phtml:0
./app/MyApp/Customer/View/Account/orders.phtml:1
./app/MyApp/Customer/View/Account/banking.phtml:1
./app/MyApp/Customer/View/Account/applycomplete.phtml:1
./app/MyApp/Customer/View/Account/catalogue.phtml:1
./app/MyApp/Customer/View/Account/classadd.phtml:0
./app/MyApp/Customer/View/Account/orders-trade.phtml:0

The first pipe grep :0$ filters this list to only include lines ending in :0:

$> find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$

./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml:0
./app/MyApp/Customer/View/Account/studio.phtml:0
./app/MyApp/Customer/View/Account/classadd.phtml:0
./app/MyApp/Customer/View/Account/orders-trade.phtml:0

The second pipe sed 's/..$//' strips off the final two characters of each line, leaving just the file paths.

$> find . -iname '*.phtml' -exec grep -H -E -o -c 'new Mustache' {} \; | grep :0$ | sed 's/..$//'

./app/MyApp/Customer/View/Account/quickcodemanagestore.phtml
./app/MyApp/Customer/View/Account/studio.phtml
./app/MyApp/Customer/View/Account/classadd.phtml
./app/MyApp/Customer/View/Account/orders-trade.phtml

When you use find, you have two basic options: filter results out after find has completed searching or use some built in option that will prevent find from considering those files and dirs matching some given pattern.

If you use the former approach on a high number of files and dirs. You will be using a lot of CPU and RAM just to pass the result on to a second process which will in turn filter out results by using a lot of resources as well.

If you use the -not keyword which is a find argument, you will be preventing any path matching the string on the -name or -regex argument behind from being considered, which will be much more efficient.

find . -not -regex ".*/foo/.*" -regex ".*"

Then, any path that is not filtered out by -not will be captured by the subsequent -regex arguments.

another alternative when grep doesn't have the -L option (IBM AIX for example), with nothing but grep and the shell :

for file in * ; do grep -q 'my_pattern' $file || echo $file ; done

For completeness the ripgrep version:

rg --files-without-match "pattern"

You can combine with file type and search path, e.g.

rg --files-without-match -t ruby "frozen_string_literal: true" app/

Open bug report

As commented by @tukan, there is an open bug report for Ag regarding the -L/--files-without-matches flag:

• ggreer/the_silver_searcher: #238 - --files-without-matches does not work properly

As there is little progress to the bug report, the -L option mentioned below should not be relied on, not as long as the bug has not been resolved. Use different approaches presented in this thread instead. Citing a comment for the bug report [emphasis mine]:

Any updates on this? -L completely ignores matches on the first line of the file. Seems like if this isn't going to be fixed soon, the flag should be removed entirely, as it effectively does not work as advertised at all.

The Silver Searcher - Ag (intended function - see bug report)

As a powerful alternative to grep, you could use the The Silver Searcher - Ag:

A code searching tool similar to ack, with a focus on speed.

Looking at man ag, we find the -L or --files-without-matches option:

...

OPTIONS
    ...

    -L --files-without-matches
           Only print the names of files that don´t contain matches.

I.e., to recursively search for files that do not match foo, from current directory:

ag -L foo

To only search current directory for files that do not match foo, simply specify --depth=0 for the recursion:

ag -L foo --depth 0

This may help others. I have mix of files Go and with test files. But I only need .go files. So I used

ls *.go | grep -v "_test.go"

-v, --invert-match select non-matching lines see https://stackoverflow.com/a/3548465

Also one can use this with vscode to open all the files from terminal

code $(ls *.go | grep -v "_test.go")