linux - Extract part of string using shell script -

strings:

"v1.0.20170728180812 latest ef1fc15" "latest ef1fc15 v1.0.20170728180812-test" "ef1fc15 v1.0.20170722150727 latest" 

---

expected string result:

"v1.0.20170728180812" "v1.0.20170728180812-test" "v1.0.20170722150727" 

code:

string='latest ef1fc15 v1.0.20170728180812-test' replace=$(echo $string | sed 's/v.*$//g') echo $string | sed -e 's/$(echo $replace)//g' 

thanks guys! ;)

this script used valid version of aws ecr, , deploy kubernetes --apply (avoiding caching when used "latest").

complete code:

ecrversions=$(aws ecr describe-images --repository-name <ecr_repo_name> --image-ids imagetag=latest --output text) appversion=$(echo $ecrversions | awk '{for (i=1;i<=nf;++i) {if($i~/^[v]/){print $i}}}') echo $appversion 

using awk:

 awk '{for (i=1;i<=nf;++i) {if($i~/^[v]/){print $i}}}' yourfile.txt 

this is:

1. iterating file record record (because that's awk does)
2. iterating each field delimited default : for (i=1;i<=nf;++i)
3. testing see if field starts "v": if($i~/^[v]/)
4. if prints field value print $i

i'm sed make quick work of too.