Fastest way to grep jar file for a particular name in it

findgrep

I am trying to find all the jars which has spring in its name. I am working with windows and using cygwin to run the linux commands. Does my below command looks right?

find . -name "*.jar" -exec jar tf '{}' \| grep -H "spring" \;

For some reason, it is still processing and haven't got the result on the screen. Any fast way to grep the jar file with a particular name?

For example, below are the valid jar files which has spring in it –

spring-web.jar
spring-core.jar
test-spring.jar

Best Answer

I do not believe the jar command accepts multiple .jar files by way of arguments so AFAIK a single jar invocation addressing all .jar files is out of the question. One option to speed things up by avoiding one find exec invocation for each .jar file is the follows

find . -name '*.jar' -exec sh -c \
'for f; do  jar -tf "$f" | grep --label="$f" "spring"; done' sh {} +

Related Solutions

Bash – how to execute lines coming from a grep result

Assumptions:

you have control over this file and are not in danger of malicious code
you want to set these variables your current shell

You could redirect your commands to a temp file and execute that:

tmp=$(mktemp)
{
    grep somedir INSTALLFILE
    grep 'export PERL5LIB' INSTALLFILE
} > "$tmp"
. "$tmp"

Or you could evaluate the results

eval "$(grep somedir INSTALLFILE)"
eval "$(grep 'export PERL5LIB' INSTALLFILE)"

Updating an old answer. What I would do today is use a process substitution:

source <(
    grep somedir INSTALLFILE
    grep 'export PERL5LIB' INSTALLFILE
)

Bash – Recursive search for a pattern, then for each match print out the specific SEQUENCE: line number, file name, and no file contents

Using grep

Why can't you just use the -r switch to grep to recurse the filesystem instead of making use of find? There are 2 additional switches I'd use too, instead of the -n switch.

$ grep -rHn PATTERN <DIR> | cut -d":" -f1-2

Example #1

$ grep -rHn PATH ~/.bashrc | cut -d":" -f1-2
/home/saml/.bashrc:25

Details

-r - recursively search through files + directories
-H - prints the name of the file if it matches (less restrictive than -l) i.e. it works with grep's other switches
-n - display the line number of the match

Example #2

$ grep -rHn PATH ~/.bash* | cut -d":" -f1-2
/home/saml/.bash_profile:10
/home/saml/.bash_profile:12
/home/saml/.bash_profile_askapache:99
/home/saml/.bash_profile_askapache:101
/home/saml/.bash_profile_askapache:118
/home/saml/.bash_profile_askapache:166
/home/saml/.bash_profile_askapache:218
/home/saml/.bash_profile_askapache:250
/home/saml/.bash_profile_askapache:314
/home/saml/.bash_profile_askapache:2317
/home/saml/.bash_profile_askapache:2323
/home/saml/.bashrc:25

Using find

$ find . -exec sh -c 'grep -Hn PATTERN "$@" | cut -d":" -f1-2' {}  +

Example

$ find ~/.bash* -exec sh -c 'grep -Hn PATH "$@" | cut -d":" -f1-2' {}  +
/home/saml/.bash_profile:10
/home/saml/.bash_profile:12
/home/saml/.bash_profile_askapache:99
/home/saml/.bash_profile_askapache:101
/home/saml/.bash_profile_askapache:118
/home/saml/.bash_profile_askapache:166
/home/saml/.bash_profile_askapache:218
/home/saml/.bash_profile_askapache:250
/home/saml/.bash_profile_askapache:314
/home/saml/.bash_profile_askapache:2317
/home/saml/.bash_profile_askapache:2323
/home/saml/.bashrc:25

If you truly want to use find you can do something like this to exec grep upon finding the files using find.