Searches for strings in files.

FINDSTR [/B] [/E] [/L] [/R] [/S] [/I] [/X] [/V] [/N] [/M] [/O] [/P] [/F:file]
[/C:string] [/G:file] [/D:dir list] [/A:color attributes]
[strings] [[drive:][path]filename[ ...]]

/B        Matches pattern if at the beginning of a line.
/E        Matches pattern if at the end of a line.
/L        Uses search strings literally.
/R        Uses search strings as regular expressions.
/S        Searches for matching files in the current directory and all
subdirectories.
/I        Specifies that the search is not to be case-sensitive.
/X        Prints lines that match exactly.
/V        Prints only lines that do not contain a match.
/N        Prints the line number before each line that matches.
/M        Prints only the filename if a file contains a match.
/O        Prints character offset before each matching line.
/P        Skip files with non-printable characters
/A:attr   Specifies color attribute with two hex digits. See "color /?"
/F:file   Reads file list from the specified file(/ stands for console).
/C:string Uses specified string as a literal search string.
/G:file   Gets search strings from the specified file(/ stands for console).
/D:dir    Search a semicolon delimited list of directories
strings   Text to be searched for.
[drive:][path]filename
Specifies a file or files to search.

Use spaces to separate multiple search strings unless the argument is prefixed
with /C.  For example
'FINDSTR "hello there" x.y' searches for "hello" or
there
in file x.y.  'FINDSTR /C:"hello there" x.y' searches for
hello there
in file x.y.

Regular expression quick reference:
.        Wildcard: any character
*        Repeat: zero or more occurances of previous character or class
^        Line position: beginning of line
$        Line position: end of line
[class]  Character class: any one character in set
[^class] Inverse class: any one character not in set
[x-y]    Range: any characters within the specified range
\x       Escape: literal use of metacharacter x
\    Word position: end of word

For full information on FINDSTR regular expressions refer to the online Command
Reference.