Grep first regex group

Question

I want to grep the first regex group of a log file with a certain pattern starting with date-time and ending with database.

Regex:

^(([0-9]{4})-([0-1][0-9])-([0-3][0-9])\s([0-1][0-9]|[2][0-3]):([0-5][0-9]):([0-5][0-9]))((.*)(\n|.)*?)(targetServerType: database)$

and I am trying the print all the previous timestamp of the occurrence of "targetServerType: database", like the following for the given log file:
2022-07-10 15:24:55
2022-07-09 13:12:42

Tried the following grep (by cutting the output also) but no success:

grep -Pzo "^(([0-9]{4})-([0-1][0-9])-([0-3][0-9])\s([0-1][0-9]|[2][0-3]):([0-5][0-9]):([0-5][0-9]))((.*)(\n|.)*?)(targetServerType: database)$" server.log

The file is something like:

    2022-07-10 15:24:55,232 ERROR [org.jboss.as.ejb3.invocation] (Thread-63 (ActiveMQ-client-global-threads-710931366))
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleInCallerTx(CMTTxInterceptor.java:159)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:256)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:329)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:239)
Caused by: com.abc.jdbc.persistence.JdbcRepositoryException:
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
        at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:73)
        at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
        at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:52)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:254)
        ... 51 more
Caused by: java.sql.SQLException: javax.resource.ResourceException:
        at org.jboss.jca.adapters.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:146)
        at org.jboss.as.connector.subsystems.datasources.WildFlyDataSource.getConnection(WildFlyDataSource.java:66)
        ... 100 more
Caused by: javax.resource.ResourceException: IJ000453: Unable to get managed connection for java:/DS.test
        at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.getManagedConnection(AbstractConnectionManager.java:656)
        at org.jboss.jca.core.connectionmanager.tx.TxConnectionManagerImpl.getManagedConnection(TxConnectionManagerImpl.java:429)
        ... 103 more
Caused by: org.postgresql.util.PSQLException: Could not find a server with specified targetServerType: database
        at org.postgresql.Driver$ConnectThread.getResult(Driver.java:401)
        at org.postgresql.Driver.connect(Driver.java:259)
        at java.sql.DriverManager.getConnection(DriverManager.java:664)
        at java.sql.DriverManager.getConnection(DriverManager.java:247)
        at org.postgresql.ds.common.BaseDataSource.getConnection(BaseDataSource.java:94)
        at org.postgresql.xa.PGXADataSource.getXAConnection(PGXADataSource.java:46)
        at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:492)
        ... 112 more
2002-07-09 18:31:54,533 INFO Testing        
2022-07-09 13:12:42,124 ERROR [org.jboss.as.ejb3.invocation] (Thread-63 (ActiveMQ-client-global-threads-710931366))
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleInCallerTx(CMTTxInterceptor.java:159)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:256)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:329)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:239)
Caused by: com.abc.jdbc.persistence.JdbcRepositoryException:
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:437)
        at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:73)
        at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
        at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:52)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:340)
        at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:254)
        ... 51 more
Caused by: java.sql.SQLException: javax.resource.ResourceException:
        at org.jboss.jca.adapters.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:146)
        at org.jboss.as.connector.subsystems.datasources.WildFlyDataSource.getConnection(WildFlyDataSource.java:66)
        ... 100 more
Caused by: javax.resource.ResourceException: IJ000453: Unable to get managed connection for java:/DS.test
        at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.getManagedConnection(AbstractConnectionManager.java:656)
        at org.jboss.jca.core.connectionmanager.tx.TxConnectionManagerImpl.getManagedConnection(TxConnectionManagerImpl.java:429)
        ... 103 more
Caused by: org.postgresql.util.PSQLException: Could not find a server with specified targetServerType: database
        at org.postgresql.Driver$ConnectThread.getResult(Driver.java:401)
        at org.postgresql.Driver.connect(Driver.java:259)
        at java.sql.DriverManager.getConnection(DriverManager.java:664)
        at java.sql.DriverManager.getConnection(DriverManager.java:247)
        at org.postgresql.ds.common.BaseDataSource.getConnection(BaseDataSource.java:94)
        at org.postgresql.xa.PGXADataSource.getXAConnection(PGXADataSource.java:46)
        at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:492)
        ... 112 more

Answer 1

You may use this simpler awk solution instead of a complex grep :

awk -F, '
/targetServerType: database$/ { print ts }
/^[0-9]{4}(-[0-9]{2}){2}/ { ts = $1 }
' file.log

2022-07-10 15:24:55
2022-07-09 13:12:42