arn:aws:iam::aws:policy/AmazonEC2FullAccess
arn:aws:iam::aws:policy/IAMFullAccess
arn:aws:iam::s:policy/CloudWatchAgentServerPolicy
arn:aws:iam::aws:policy/AdministratorAccess
arn:aws:iam::aws:policy/aws-service-role/AWSSupportServiceRolePolicy
arn:aws:iam::aws:policy/aws-service-role/AWSTrustedAdvisorServiceRolePolicy
arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
arn:aws:iam::aws:policy/aws-service-role/AmazonElasticFileSystemServiceRolePolicy
arn:aws:iam::aws:policy/IAMAccessAnalyzerFullAccess
arn:aws:iam::aws:policy/aws-service-role/AWSBackupServiceLinkedRolePolicyForBackup

Here i need only the policy names which is at the end.

I need only the letters after /

this is the regex am using (?<=/).*

the output of this regex is this

1. arn:aws:iam::aws:policy/AdministratorAccess

2. arn:aws:iam::aws:policy/aws-service-role/AWSSupportServiceRolePolicy

As you can see in 1) it is greping correctly, but in 2) i need the letters after the last occurrence of /

and i need to delete everything except the match case.

Kindly someone drop your suggestions to achieve this.

Note: am aware that i can get the aws policy names using boto3, but am curious about the above usecase.

CodePudding user response：

You can just use grep with regexp and write result in another file. the remove original, if you want. Something like

grep -Eao '\(?<=/).*' 'logs.log' >result.log

CodePudding user response：

You can use the lookbehind assertion, and then match any char except a / or newline till the end of the string [^/\r\n] $

(?<=/)[^/\r\n] $

See a regex demo

If you use PCRE, you can also make use of \K to forget what is matched so far.

.*\/\K[^/\r\n] $

See another regex demo.