138

I would like to get the multi pattern match with implicit AND between patterns, i.e. equivalent to running several greps in a sequence:

grep pattern1 | grep pattern2 | ...

So how to convert it to something like?

grep pattern1 & pattern2 & pattern3

I would like to use single grep because I am building arguments dynamically, so everything has to fit in one string. Using filter is system feature, not grep, so it is not an argument for it.


Don't confuse this question with:

grep "pattern1\|pattern2\|..."

This is an OR multi pattern match. I am looking for an AND pattern match.

3

9 Answers 9

113

To find the lines that match each and everyone of a list of patterns, agrep (the original one, now shipped with glimpse, not the unrelated one in the TRE regexp library) can do it with this syntax:

agrep 'pattern1;pattern2'

With GNU grep, when built with PCRE support, you can do:

grep -P '^(?=.*pattern1)(?=.*pattern2)'

With ast grep:

grep -X '.*pattern1.*&.*pattern2.*'

(adding .*s as <x>&<y> matches strings that match both <x> and <y> exactly, a&b would never match as there's no such string that can be both a and b at the same time).

If the patterns don't overlap, you may also be able to do:

grep -e 'pattern1.*pattern2' -e 'pattern2.*pattern1'

The best portable way is probably with awk as already mentioned:

awk '/pattern1/ && /pattern2/'

Or with sed:

sed -e '/pattern1/!d' -e '/pattern2/!d'

Or perl:

perl -ne 'print if /pattern1/ && /pattern2/'

Please beware that all those will have different regular expression syntaxes.

16
  • 3
    The agrep syntax is not working for me... which version was it introduced in?
    – Raman
    Sep 5, 2016 at 22:15
  • 2
    @Raman, yours sounds like TRE agrep. Sep 6, 2016 at 7:01
  • 3
    @Techiee, or just awk '/p1/ && /p2/ {n++}; END {print 0+n}' Jun 28, 2017 at 20:23
  • 1
    @ChamindaBandara, you ran that with GNU grep instead of ast grep. GNU grep has no support for ast augmented regexp. It does have an undocumented -X option, but that's for something unrelated, it's to specify the regexp flavour (matcher) like in grep -X perl being the same as grep -P. Feb 17, 2021 at 9:00
  • 1
    @DanielKaplan, from your recent question, I suspect you're looking for something difference from what this Q&A is about. Here we're trying to find lines that match all patterns, while you may be trying to find files for which all patterns are matched by any line (there are several Q&As here covering that). I've edited the answer to maybe make that more obvious. Mar 10 at 7:32
27

You didn't specify grep version, this is important. Some regexp engines allow multiple matching groupped by AND using '&' but this is non-standard and non-portable feature. But, at least GNU grep doesn't support this.

OTOH you can simply replace grep with sed, awk, perl, etc. (listed in order of weight increasing). With awk, the command would look like

awk '/regexp1/ && /regexp2/ && /regexp3/ { print; }'

and it can be constructed to be specified in command line in easy way.

4
  • 4
    Just remember that awk uses ERE's, e.g. the equivalent of grep -E, as opposed to the BRE's that plain grep uses.
    – jw013
    Nov 10, 2012 at 9:42
  • 4
    awk's regexes are called EREs, but in fact they're a bit idiosyncratic. Here are probably more details than anyone cares for: wiki.alpinelinux.org/wiki/Regex
    – dubiousjim
    Nov 10, 2012 at 15:35
  • Thank you, grep 2.7.3 (openSUSE). I upvoted you, but I will keep question open for a while, maybe there is some trick for grep (not that I dislike awk -- simply knowing more is better). Nov 10, 2012 at 15:42
  • 3
    The default action is to print the matching line so the { print; } part isn't really necessary or useful here.
    – tripleee
    Apr 20, 2017 at 11:58
13

grep pattern1 | grep pattern2 | ...

I would like to use single grep because I am building arguments dynamically, so everything has to fit in one string

It's actually possible to build the pipeline dynamically (without resorting to eval):

# Executes: grep "$1" | grep "$2" | grep "$3" | ...
function chained-grep {
    local pattern="$1"
    if [[ -z "$pattern" ]]; then
        cat
        return
    fi    

    shift
    grep -- "$pattern" | chained-grep "$@"
}

cat something | chained-grep all patterns must match order but matter dont

It's probably not a very efficient solution though.

3
  • 1
    Use either chained-grep() or function chained-grep but not function chained-grep(): unix.stackexchange.com/questions/73750/…
    – nisetama
    Jan 19, 2019 at 17:08
  • Can you describe what the trick is? Can you add it to the answer (without "Edit:", "Update:", or similar ) by editing it? Oct 30, 2020 at 20:40
  • Reformulated the answer to make the trick clearer (ie.: build a shell pipeline dynamically)
    – olejorgenb
    Oct 30, 2020 at 23:21
12

git grep

Here is the syntax using git grep combining multiple patterns using Boolean expressions:

git grep --no-index -e pattern1 --and -e pattern2 --and -e pattern3

The above command will print lines matching all the patterns at once.

--no-index Search files in the current directory that is not managed by Git.

Check man git-grep for help.

See also:

For OR operation, see:

2
  • 1
    Superb answer. Thank you. Oct 6, 2020 at 9:22
  • This worked the best for me
    – user582175
    Mar 25, 2021 at 17:37
11
+50

If patterns contains one pattern per line, you can do something like this:

awk 'NR==FNR{a[$0];next}{for(i in a)if($0!~i)next}1' patterns -

Or this matches substrings instead of regular expressions:

awk 'NR==FNR{a[$0];next}{for(i in a)if(!index($0,i))next}1' patterns -

To print all instead of no lines of the input in the case that patterns is empty, replace NR==FNR with FILENAME==ARGV[1], or with ARGIND==1 in gawk.

These functions print the lines of STDIN which contain each string specified as an argument as a substring. ga stands for grep all and gai ignores case.

ga(){ awk 'FILENAME==ARGV[1]{a[$0];next}{for(i in a)if(!index($0,i))next}1' <(printf %s\\n "$@") -; }
gai(){ awk 'FILENAME==ARGV[1]{a[tolower($0)];next}{for(i in a)if(!index(tolower($0),i))next}1' <(printf %s\\n "$@") -; }
1
  • crisp answer which addresss several uses cases and works (verified on macos) Aug 8, 2020 at 18:19
3

Here's my take, and this works for words in multiple lines:

Use find . -type f followed by as many
-exec grep -q 'first_word' {} \;
and the last keyword with
-exec grep -l 'nth_word' {} \;

-q quiet / silent
-l show files with matches

The following returns list of filenames with words 'rabbit' and 'hole' in them:
find . -type f -exec grep -q 'rabbit' {} \; -exec grep -l 'hole' {} \;

1
  • If you look carefully, you just might learn that this is not the functionality that the question is asking for. Dec 7, 2020 at 5:40
2

to search multiple files for the presence of two patterns anywhere in the file use

awk -v RS="" '/patern1/&&/patern2/{print FILENAME}' file1 ... filen
2
  • Grep is all too often used where (IMO) awk would be better. I like this answer for exactly that reason, and of course awk can do further processing such as printing only fields 6 and 2 from the input. Jun 1, 2021 at 10:20
  • This doesn't actually address the OP's question, but +1 'cause I think it's very useful for other related situations & reveals the strength of awk... if you had to choose awk or grep, I think it's clear. Fortunately we don't have to make this choice :)
    – Seamus
    Feb 19 at 0:54
1

ripgrep

Here is the example using rg:

rg -N '(?P<p1>.*pattern1.*)(?P<p2>.*pattern2.*)(?P<p3>.*pattern3.*)' file.txt

It's one of the quickest grepping tools, since it's built on top of Rust's regex engine which uses finite automata, SIMD and aggressive literal optimizations to make searching very fast.

See also related feature request at GH-875.

-2

To find all of the words (or patterns), you can run grep in a for loop. The main advantage here is searching from a list of regular expressions.

A real example:

# File 'search_all_regex_and_error_if_missing.sh'

find_list="\
^a+$ \
^b+$ \
^h+$ \
^d+$ \
"

for item in $find_list; do
   if grep -E "$item" file_to_search_within.txt
   then
       echo "$item found in file."
   else
       echo "Error: $item not found in file. Exiting!"
       exit 1
   fi
done

Now let's run it on this file:

hhhhhhhhhh
aaaaaaa
bbbbbbbbb
ababbabaabbaaa
ccccccc
dsfsdf
bbbb
cccdd
aa
caa
$ ./search_all_regex_and_error_if_missing.sh
aaaaaaa aa
^a+$ found in file.
bbbbbbbbb bbbb
^b+$ found in file.
hhhhhhhhhh
^h+$ found in file.
Error: ^d+$ not found in file. Exiting!
8
  • 1
    Your logic is faulty -- I asked for ALL operator, your code works as OR operator, not AND. And btw. for that (OR) is much easier solution given right in the question. Aug 14, 2018 at 22:18
  • @greenoldman The logic is simple: The for will loop on ALL of the words/patterns in the list, and if it is found in file - will print it. So just remove the else if you don't need action in case word was not found.
    – Noam Manos
    Aug 16, 2018 at 15:07
  • 1
    I understand your logic as well as my question -- I was asking about AND operator, meaning the file is only a positive hit if it matches pattern A and pattern B and pattern C and... AND In you case file is positive hit if it matches pattern A or pattern B or... Do you see the difference now? Aug 17, 2018 at 6:19
  • @greenoldman not sure why you think this loop does not check AND condition for all patterns? So I've edited my answer with a real example: It will search in file for all regex of list, and on the first one which is missing - will exit with error.
    – Noam Manos
    Aug 19, 2018 at 15:04
  • You have it right in front of your eyes, you have positive match just after first match is executed. You should have "collect" all outcomes and compute AND on them. Then you should rewrite the script to run on multiple files -- then maybe you realize that the question is already answered and your attempt does not bring anything to the table, sorry. Aug 20, 2018 at 5:56

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