Search for a text string against all *.log files of current folder:
1. List files of given type w/given string:
find . -name "*.log" -exec grep -l "<search_text>" {} \;
2. Print all matches in files of given type:
find . -name "*.log" -exec grep -A 3 -B 3 "<search_text>" {} \;
where -A and -B indicates the number of lines to print after and before found matches.
3. Replace strings in files:
replace 'windows' --> 'linux' in all files of current dir
grep -rl 'windows' . | xargs sed -i 's/windows/linux/g'
And, sure, you can use the UI tools for simple search/replace actions.
Example: regexxer search tool.
