# 2.11BSD#431 - /usr/man/cat1/egrep.0

    GREP(1)             UNIX Programmer's Manual		  GREP(1)

    NAME
         grep, egrep, fgrep - search a file for a pattern

    SYNOPSIS
         grep [ option ] ...  expression [ file ] ...

         egrep [ option ] ...  [ expression ] [ file ] ...

         fgrep [ option ] ...  [ strings ] [ file ]

    DESCRIPTION
         Commands of the grep family search the input files (standard
         input default) for lines matching a pattern.  Normally, each
         line found is copied to the standard output.  Grep patterns
         are limited regular expressions in the style of ex(1); it
         uses a compact nondeterministic algorithm.  Egrep patterns
         are full regular expressions; it uses a fast deterministic
         algorithm that sometimes needs exponential space.	Fgrep
         patterns are fixed strings; it is fast and compact.  The
         following options are recognized.

         -v   All lines but those matching are printed.

         -x   (Exact) only lines matched in their entirety are
    	  printed (fgrep only).

         -c   Only a count of matching lines is printed.

         -l   The names of files with matching lines are listed
    	  (once) separated by newlines.

         -n   Each line is preceded by its relative line number in
    	  the file.

         -b   Each line is preceded by the block number on which it
    	  was found.  This is sometimes useful in locating disk
    	  block numbers by context.

         -i   The case of letters is ignored in making comparisons -
    	  that is, upper and lower case are considered identical.
    	  This applies to grep and fgrep only.

         -s   Silent mode.	Nothing is printed (except error mes-
    	  sages).  This is useful for checking the error status.

         -w   The expression is searched for as a word (as if sur-
    	  rounded by `\<' and `\>', see ex(1).) (grep only)

         -e expression
    	  Same as a simple expression argument, but useful when
    	  the expression begins with a -.

    Printed 11/26/99	 April 29, 1985                         1

    GREP(1)             UNIX Programmer's Manual		  GREP(1)

         -f file
    	  The regular expression (egrep) or string list (fgrep)
    	  is taken from the file.

         In all cases the file name is shown if there is more than
         one input file.  Care should be taken when using the charac-
         ters $ * [ ^ | ( ) and \ in the expression as they are also
         meaningful to the Shell.  It is safest to enclose the entire
         expression argument in single quotes ' '.

         Fgrep searches for lines that contain one of the (newline-
         separated) strings.

         Egrep accepts extended regular expressions.  In the follow-
         ing description `character' excludes newline:

    	  A \ followed by a single character other than newline
    	  matches that character.

    	  The character ^ matches the beginning of a line.

    	  The character $ matches the end of a line.

    	  A . (period) matches any character.

    	  A single character not otherwise endowed with special
    	  meaning matches that character.

    	  A string enclosed in brackets [] matches any single
    	  character from the string.  Ranges of ASCII character
    	  codes may be abbreviated as in `a-z0-9'.  A ] may occur
    	  only as the first character of the string.  A literal -
    	  must be placed where it can't be mistaken as a range
    	  indicator.

    	  A regular expression followed by an * (asterisk)
    	  matches a sequence of 0 or more matches of the regular
    	  expression.  A regular expression followed by a +
    	  (plus) matches a sequence of 1 or more matches of the
    	  regular expression.  A regular expression followed by a
    	  ? (question mark) matches a sequence of 0 or 1 matches
    	  of the regular expression.

    	  Two regular expressions concatenated match a match of
    	  the first followed by a match of the second.

    	  Two regular expressions separated by | or newline match
    	  either a match for the first or a match for the second.

    	  A regular expression enclosed in parentheses matches a
    	  match for the regular expression.

    Printed 11/26/99	 April 29, 1985                         2

    GREP(1)             UNIX Programmer's Manual		  GREP(1)

         The order of precedence of operators at the same parenthesis
         level is [] then *+? then concatenation then | and newline.

         Ideally there should be only one grep, but we don't know a
         single algorithm that spans a wide enough range of space-
         time tradeoffs.

    SEE ALSO
         ex(1), sed(1), sh(1)

    DIAGNOSTICS
         Exit status is 0 if any matches are found, 1 if none, 2 for
         syntax errors or inaccessible files.

    BUGS
         Lines are limited to 256 characters; longer lines are trun-
         cated.

    Printed 11/26/99	 April 29, 1985                         3

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