The -x gives explanations to the log text when available
The -e jumps to the end of the log
The -f shows only the most recent journal entries, and continuously print
new entries as they are appended to the journal

tail -f /var/log/messages

more * | cat

or

tail -n +1 file1 file2

I like to start these type of recursive runs in the root directory of the search. So in our test case I would do the following:

Eg. Find the port number 8080 in multiple .xml files and replace it with the port number 15001.

1. cd /path/rootdirectoryofsearch

*note – Change which files get examined by changing the extension type:

2. Then run the command
   With Backup .mybackup
   find . -type f -name “*.xml” -exec sed -i.mybackup -e ‘s/8080/15001/g’ {} +
3. Delete backups:
   find . -name “*.mybackup” -type f – delete
4. With Backup
   find . -type f -name “*.xml” -exec sed -i” ‘s/8080/15001/g’ {} +

cat list.txt | xargs -n1 | sort | uniq -c