mjhjmtu

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.

agrep 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/'

With sed:

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

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

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.

This is not a very good solution but illustrates a somewhat cool "trick"

function chained-grep() chained-grep "$@"


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

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

awk 'NR==FNRa[$0];nextfor(i in a)if($0!~i)next1' patterns.txt -

To search for fixed strings instead of regular expressions, use this variant:

awk 'NR==FNRa[$0];nextfor(i in a)if(!index($0,i))next1' patterns.txt -

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

git grep

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

git grep -e pattern1 --and -e pattern2 --and -e pattern3

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

If the files aren't under version control, add --no-index param.

Search files in the current directory that is not managed by Git.

Check man git-grep for help.

See also: Check if all of multiple strings or regexes exist in a file.

This shell command may help:

eval "</dev/stdin $(printf "|grep '%s'" pattern1 pattern2)" FILE

However it's easier if all your patterns are stored in the file, so you can define the following alias:

alias grep-all="cat $(xargs printf '| grep "%s"' < patterns.txt)"

and use it as:

cat text.txt | grep-all

You can of course modify the alias depending on your required syntax, so with this alias:

alias grep-all="</dev/stdin $(xargs printf '|grep "%s"' < patterns.txt)"

you can use just a single command, e.g.

grep-all text.txt

For more ideas, check also: Match all patterns from file at once.

For AND operation per file, see: Check if all of multiple strings or regexes exist in a file.