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BSD 2.11 - man page for egrep (bsd section 1)

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GREP(1) 										  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 nonde-
       terministic algorithm.  Egrep patterns are full regular expressions; it uses a fast deter-
       ministic  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  messages).   This  is  useful  for
	      checking the error status.

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

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

       -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 characters $ * [ ^ | ( ) 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  following  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 charac-
	      ter.

	      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.

       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 truncated.

4th Berkeley Distribution		  April 29, 1985				  GREP(1)


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