sajad torkamani
grep -rin "127.0.0.1" $HOME/sites

This will recursively search the path $HOME/sites and print all the lines that match the text 127.0.0.1.

-R, -r, --recursive Read all files under each directory, recursively; this is equivalent to the -d recurse option.
-i, --ignore-case Ignore case distinctions in both the PATTERN and the input files. (-i is specified by POSIX.)
-n, --line-number Prefix each line of output with the 1-based line number within its input file. (-n is specified by POSIX.)
grep searches the named input FILEs (or standard input if no files are named, or if a single hyphen-minus (-) is given as file name) for lines containing a match to the given PATTERN. By default, grep prints the matching lines.
Tagged: Unix