Find and replace a string

find /home/bruno/old-friends -type f -exec sed -i 's/ugly/beautiful/g' {} \;

1. Find a string (only in alphabets)

# grep -rw "search string" ./

2. Find a string

# grep -i -l "search string" * -r 2> /dev/null

2>/dev/null : direct error outputs to /dev/null

3. Find a string(all languages can be used for search string)

# find . -exec grep -l "search string" {} \; 2>/dev/null

4. Find a string(case insensitive)

# find . -exec grep -i -l "search string" {} \; 2>/dev/null

-i: case insensitive

5. Find and replace a string

# find . -exec perl -pi -e 's/search string/replace string/g' {} \; 2>/dev/null

# find . -type f -exec sed -i 's/ugly/beautiful/g' {} \;

6. Find a file

# find / -name filename -type f

7. Find a file(case insensitive)

# find / -iname filename -type f

8. Find a directory

# find / -name filename -type d

9. Find a directory(case insensitive)

# find / -iname directoryname -type d

10. Find all files that matches to the filename

find . | xargs grep 'filename'

Source:
http://www.brunolinux.com/02-The_Terminal/Find_and%20Replace_with_Sed.html
http://apms.tistory.com/tag/replace