truncating files

>/catalina.out

du

To get all the large files with size greater than 1000MB

find . -xdev -type f -size +1000M -exec du -sh {} + 

To get large files with their time stamp

find . -xdev -type f -size +100M -exec du -sh {} + | awk {'print $2'} | xargs ls -ltrh | grep *.out 

Find all the files in current directory which are older than 1 month

find ./ -maxdepth 1 -type f -mtime +30 -print 
find ./ -maxdepth 1 -type f -mtime +30 

Move the files older than 30 days to a particular directory

$ mkdir tmp 
$ find ./ -maxdepth 1 -type f -mtime +30 -exec mv -t ./tmp/ {} + 
$ rm -rf tmp

egrep

To change all occurrences of ‘AdminServer’ with ‘prdAdminServer’

$ egrep -rl "AdminServer" *| xargs sed -i 's/AdminServer/prdAdminServer/g' 
  
$ egrep -r "AdminServer" * 
bin/setDomainEnv.sh:    SERVER_NAME="AdminServer"  
 
$ egrep -rl "AdminServer" bin/setDomainEnv.sh | xargs sed -i 's/AdminServer/prdAdminServer/g' 
 
$ egrep -r "AdminServer" bin/setDomainEnv.sh 
        SERVER_NAME="prdAdminServer" 

To print all files containing keyword ‘ns-exports-interfaces’ except .svn, starting with Binary or Starting with ./out1.txt”

$ egrep "ns-exports-interfaces*" `find . -type f -print` | egrep -v ".svn|^Binary file|^./out1.txt"

find

To find specific pom files and zip them into a file

find . -name Build-2019-03-09-23-38-pom-090319.xls -o -name Build-2019-03-12-23-05-pom-120319.xls -o -name Build-2019-03-13-07-46-pom-130319.xls|xargs zip -r 123.zip

To find all the files of size greater than 1000M and print their sizes

find /apps/ -xdev -type f -size +1000M -exec du -sh {} + 

To print all the files with size greater than 1G

find /apps/ap_frm/servers/apache-tomcat-8.5.38_pfm/logs/ -size +1G -type f -print

To find all files with specific extension greater than 100MB, not been modified since last 3 days from current path

find . -size +100M -mtime +3 -type f \( -name "*.log" -o -name "*.txt" -o -name "*.out" \)

To print all *.pomxml files containing the keyword “ns-exports-interfaces”

$ find . -name "*pom.xml" -exec egrep -n -A 2 "<artifactId>ns-exports-interfaces</artifactId>" '{}' \; -print

To print all *.xml files containing keyword “insert into gen_mst_rpt” except the ones with “insert into gen_mst_rpt_param”

$ find . -name "*xml" -exec egrep -n -A 2 "*insert into gen_mst_rpt *" -v "*insert into gen_mst_rpt_param*" '{}' \; -print 

for

Example of customized case when we can check the SVN URLs

for i in `cat  ~/.BUILD_SCRIPTS_AREA/modules.full`; do svn info $i | grep URL; done | awk {'print $2'} 

To check and print all the log files in path /apps/ap_frm/servers/apache-tomcat-8.5.38_pfm/logs/ which have not been modified since last 3 days and can be of type *.log OR *.txt

You can also remove all those files but BE VERY CAREFUL when you execute rm -rf instead of ls -ltrh

for j in `find /apps/ap_frm/servers/apache-tomcat-8.5.38_pfm/logs/ -mtime +3 -type f \( -name "*.log" -o -name "*.txt" -o -name "*.out" \)`;do echo $j; ls -ltrh $j; done;

nohup

To run the sql queries in background

nohup sqlplus USERNAME/PASSWORD@DBNAME @/apps/home/dbfile.sql &

ps

ps -p <pid> -o %cpu,%mem,cmd

To check which all Oracle Databases are running in the DB server

[username@hostname ~]$ ps -ef | grep pmon | grep oracle
oracle   23274     1  0 Aug19 ?        00:11:08 ora_pmon_db1
oracle   23689     1  0 Aug19 ?        00:12:12 ora_pmon_db2

ssh

To login using the bastion server

$ ssh -o ProxyCommand="ssh -i private_key_to_login.pem -W %h:%p ubuntu@bastion.host.link" -i private_key_to_login.pem ubuntu@172.126.146.224 -vvvvv