複数のファイルの中から検索

次のいずれかを実行できます。

grep pattern_search . ＃現在のディレクトリで通常のgrepを実行します。

grep pattern_search * ＃現在のディレクトリのすべてのワイルドカードファイルに通常のgrepを使用します。

grep -R pattern_search . ＃現在のディレクトリで再帰検索を使用します。

grep -H pattern_search *＃ファイルが2つ以上の場合はファイル名を出力します。 「-時間」

（gnuマニュアルから）次のような他のオプション：

--directories=action
    If an input file is a directory, use action to process it. By default, 
    action is ‘read’, which means that directories are read just as if they 
    were ordinary files (some operating systems and file systems disallow 
    this, and will cause grep to print error messages for every directory 
    or silently skip them). If action is ‘skip’, directories are silently 
    skipped. If action is ‘recurse’, grep reads all files under each 
    directory, recursively; this is equivalent to the ‘-r’ option. 
--exclude=glob
    Skip files whose base name matches glob (using wildcard matching). A 
    file-name glob can use ‘*’, ‘?’, and ‘[’...‘]’ as wildcards, and \ to 
    quote a wildcard or backslash character literally. 
--exclude-from=file
    Skip files whose base name matches any of the file-name globs read from 
    file (using wildcard matching as described under ‘--exclude’). 
--exclude-dir=dir
    Exclude directories matching the pattern dir from recursive directory 
    searches. 
-I
    Process a binary file as if it did not contain matching data; this is 
    equivalent to the ‘--binary-files=without-match’ option. 
--include=glob
    Search only files whose base name matches glob (using wildcard matching 
    as described under ‘--exclude’). 
-r
-R
--recursive
    For each directory mentioned on the command line, read and process all 
    files in that directory, recursively. This is the same as the 
    --directories=recurse option.
--with-filename
    Print the file name for each match. This is the default when there is 
    more than one file to search.