|  | 
 NAME     
 |  |  |  | grep, g – search a file for a pattern 
 | 
 SYNOPSIS     
 |  |  |  | grep [ option ... ] pattern [ file ... ] 
    
    
    g [ option ... ] pattern [ file ... ] 
 | 
 DESCRIPTION     
 |  |  |  | Grep searches the input files (standard input default) for lines
    that match the pattern, a regular expression as defined in regexp(7)
    with the addition of a newline character as an alternative (substitute
    for |) with lowest precedence. Normally, each line matching the
    pattern is ‘selected’, and each selected line is copied to the
    standard output. The options
    are −c    Print only a count of matching lines.
 −h    Do not print file name tags (headers) with output lines.
 −e    The following argument is taken as a pattern. This option makes
    it easy to specify patterns that might confuse argument parsing,
    such as −n.
 −i    Ignore alphabetic case distinctions. The implementation folds
    into lower case all letters in the pattern and input before interpretation.
    Matched lines are printed in their original form.
 −l    (ell) Print the names of files with selected lines; don’t print
    the lines.
 −L    Print the names of files with no selected lines; the converse
    of −l.
 −n    Mark each printed line with its line number counted in its file.
 −s    Produce no output, but return status.
 −v    Reverse: print lines that do not match the pattern.
 −f    The pattern argument is the name of a file containing regular
    expressions one per line.
 −b    Don’t buffer the output: write each output line as soon as it
    is discovered. 
    
    
    Output lines are tagged by file name when there is more than one
    input file. (To force this tagging, include /dev/null as a file
    name argument.) 
    
    
    Care should be taken when using the shell metacharacters $*[^|()=\
    and newline in pattern; it is safest to enclose the entire expression
    in single quotes '...'. An expression starting with ’*’ will treat
    the rest of the expression as literal characters. 
    
    
    G invokes grep with −n and forces tagging of output lines by file
    name. If no files are listed, it searches all files matching
 
 |  |  |  | *.C *.b *.c *.h *.m *.cc *.java *.cgi *.pl *.py *.tex *.ms 
 | 
 | 
 SOURCE     
 SEE ALSO    
 DIAGNOSTICS     
 |  |  |  | Exit status is null if any lines are selected, or non-null when
    no lines are selected or an error occurs. 
 | 
 |  |