1GREP(1)                     General Commands Manual                    GREP(1)
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NAME

6       grep, egrep, fgrep - search a file for a pattern
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SYNOPSIS

9       grep [ option ] ...  expression [ file ] ...
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11       egrep [ option ] ...  [ expression ] [ file ] ...
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13       fgrep [ option ] ...  [ strings ] [ file ]
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DESCRIPTION

16       Commands  of  the  grep  family  search the input files (standard input
17       default) for lines matching a pattern.  Normally, each  line  found  is
18       copied  to  the  standard  output.   Grep  patterns are limited regular
19       expressions in the style of ex(1); it uses a  compact  nondeterministic
20       algorithm.  Egrep patterns are full regular expressions; it uses a fast
21       deterministic algorithm that sometimes needs exponential space.   Fgrep
22       patterns  are  fixed  strings;  it  is fast and compact.  The following
23       options are recognized.
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25       -v     All lines but those matching are printed.
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27       -x     (Exact) only lines matched in their entirety are printed  (fgrep
28              only).
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30       -c     Only a count of matching lines is printed.
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32       -l     The  names  of files with matching lines are listed (once) sepa‐
33              rated by newlines.
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35       -n     Each line is preceded by its relative line number in the file.
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37       -b     Each line is preceded by the block number on which it was found.
38              This  is sometimes useful in locating disk block numbers by con‐
39              text.
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41       -i     The case of letters is ignored in making comparisons — that  is,
42              upper  and lower case are considered identical.  This applies to
43              grep and fgrep only.
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45       -s     Silent mode.  Nothing is printed (except error messages).   This
46              is useful for checking the error status.
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48       -w     The  expression  is  searched for as a word (as if surrounded by
49              `\<' and `\>', see ex(1).)  (grep only)
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51       -e expression
52              Same as a  simple  expression  argument,  but  useful  when  the
53              expression begins with a -.
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55       -f file
56              The  regular  expression (egrep) or string list (fgrep) is taken
57              from the file.
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59       In all cases the file name is shown if there is  more  than  one  input
60       file.  Care should be taken when using the characters $ * [ ^ | ( ) and
61       \ in the expression as they are also meaningful to the  Shell.   It  is
62       safest to enclose the entire expression argument in single quotes ´ ´.
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64       Fgrep  searches  for  lines that contain one of the (newline-separated)
65       strings.
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67       Egrep accepts extended regular expressions.  In the following  descrip‐
68       tion `character' excludes newline:
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70              A  \  followed  by a single character other than newline matches
71              that character.
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73              The character ^ matches the beginning of a line.
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75              The character $ matches the end of a line.
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77              A .  (period) matches any character.
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79              A single character not otherwise endowed  with  special  meaning
80              matches that character.
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82              A  string  enclosed  in brackets [] matches any single character
83              from the string.  Ranges of ASCII character codes may be  abbre‐
84              viated  as in `a-z0-9'.  A ] may occur only as the first charac‐
85              ter of the string.  A literal - must be placed where it can't be
86              mistaken as a range indicator.
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88              A  regular  expression  followed  by  an  * (asterisk) matches a
89              sequence of 0 or more matches of the regular expression.  A reg‐
90              ular  expression  followed by a + (plus) matches a sequence of 1
91              or more matches of the regular expression.  A regular expression
92              followed  by  a  ?  (question mark) matches a sequence of 0 or 1
93              matches of the regular expression.
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95              Two regular expressions concatenated match a match of the  first
96              followed by a match of the second.
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98              Two regular expressions separated by | or newline match either a
99              match for the first or a match for the second.
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101              A regular expression enclosed in parentheses matches a match for
102              the regular expression.
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104       The  order  of precedence of operators at the same parenthesis level is
105       [] then *+? then concatenation then | and newline.
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107       Ideally there should be only one grep, but we don't know a single algo‐
108       rithm that spans a wide enough range of space-time tradeoffs.
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SEE ALSO

111       ex(1), sed(1), sh(1)
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DIAGNOSTICS

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

118       Lines are limited to 256 characters; longer lines are truncated.
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1224th Berkeley Distribution       April 29, 1985                         GREP(1)