usr/man/cat1/egrep.0



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


N\bNA\bAM\bME\bE
     grep, egrep, fgrep - search a file for a pattern

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     g\bgr\bre\bep\bp [ option ] ...  expression [ file ] ...

     e\beg\bgr\bre\bep\bp [ option ] ...  [ expression ] [ file ] ...

     f\bfg\bgr\bre\bep\bp [ option ] ...  [ strings ] [ file ]

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     Commands of the _\bg_\br_\be_\bp family search the input _\bf_\bi_\bl_\be_\bs (standard
     input default) for lines matching a pattern.  Normally, each
     line found is copied to the standard output.  _\bG_\br_\be_\bp patterns
     are limited regular expressions in the style of _\be_\bx(1); it
     uses a compact nondeterministic algorithm.  _\bE_\bg_\br_\be_\bp patterns
     are full regular expressions; it uses a fast deterministic
     algorithm that sometimes needs exponential space.  _\bF_\bg_\br_\be_\bp
     patterns are fixed strings; it is fast and compact.  The
     following options are recognized.

     -\b-v\bv   All lines but those matching are printed.

     -\b-x\bx   (Exact) only lines matched in their entirety are
          printed (_\bf_\bg_\br_\be_\bp only).

     -\b-c\bc   Only a count of matching lines is printed.

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

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

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

     -\b-h\bh   Never print filename headers with output lines.

     -\b-o\bo   Always print filename headers with output lines.

     -\b-i\bi   The case of letters is ignored in making comparisons -
          that is, upper and lower case are considered identical.

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

     -\b-w\bw   The expression is searched for as a word (as if sur-
          rounded by `\<' and `\>', see _\be_\bx(1).) (_\bg_\br_\be_\bp only)

     -\b-e\be _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn


Printed 7/9/88           October 8, 1987                        1


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


          Same as a simple _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn argument, but useful when
          the _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn begins with a -.

     -\b-f\bf _\bf_\bi_\bl_\be
          The regular expression (_\be_\bg_\br_\be_\bp) or string list (_\bf_\bg_\br_\be_\bp)
          is taken from the _\bf_\bi_\bl_\be.

     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 _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn as they are also
     meaningful to the Shell.  It is safest to enclose the entire
     _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn argument in single quotes ' '.

     _\bF_\bg_\br_\be_\bp searches for lines that contain one of the (newline-
     separated) _\bs_\bt_\br_\bi_\bn_\bg_\bs.

     _\bE_\bg_\br_\be_\bp 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 .\b. (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.


Printed 7/9/88           October 8, 1987                        2


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


          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 _\bg_\br_\be_\bp, but we don't know a
     single algorithm that spans a wide enough range of space-
     time tradeoffs.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     ex(1), sed(1), sh(1)

D\bDI\bIA\bAG\bGN\bNO\bOS\bST\bTI\bIC\bCS\bS
     Exit status is 0 if any matches are found, 1 if none, 2 for
     syntax errors or inaccessible files.

B\bBU\bUG\bGS\bS
     Lines are limited to 256 characters; longer lines are trun-
     cated.


Printed 7/9/88           October 8, 1987                        3