Searching for files by patterns in name/contents

A common and task of someone using the Linux Command Line (shell) are to search for files/directories with a certain name or containing certain text. There are 2 commands you should familiarise yourself with in order to
accomplish this:

Find files by name
find /var/www -name ‘*.css’

This will print out the full path/filename to all files under /var/www that end in .css. Example output:

/var/www/html/text-cursor.css
/var/www/html/style.css

For more info:

man find

Find files containing text
grep font /var/www/html/style.css

This will print all lines containing the pattern font in the specified file. Example output:

font-weight: bold;
font-family: monospace;

Another example:
grep font /var/www/html/

This doesn’t work as you’d hoped. You get:
grep: /var/www/html/: Is a directory

You need to grep recursively to make it work, using the -R option:
grep -R font /var/www/html/

Hey, nice! Check out the output of this one:

/var/www/html/admin/index.php: echo '<font color=red><b>Error: no dice</b></font><br/>';

/var/www/html/admin/index.php: echo '<font color=red><b>Error: try again</b></font><br/>';

/var/www/html/style.css: font-weight: bold; 
/var/www/html/style.css: font-family: monospace;

Notice that when to grep is matching multiple files, it prefixes the matched lines with the filenames. You can use the -h option to get rid of that if you want.

For more info:
man grep