egrep(1)                 USER COMMANDS                   egrep(1)



NAME
     egrep - search a file  for  a  pattern  using  full  regular
     expressions

SYNOPSIS
     egrep [options] full regular expression [file ...]

DESCRIPTION
     egrep (expression grep) searches  files  for  a  pattern  of
     characters  and  prints all lines that contain that pattern.
     egrep uses full regular expressions (expressions  that  have
     string values that use the full set of alphanumeric and spe-
     cial characters) to match the  patterns.   It  uses  a  fast
     deterministic  algorithm  that  sometimes  needs exponential
     space.

     egrep accepts full regular expressions as in  ed(1),  except
     for \( and \), with the addition of:

     1.    A full regular expression followed by +  that  matches
           one  or  more  occurrences of the full regular expres-
           sion.
     2.    A full regular expression followed by ?  that  matches
           0 or 1 occurrences of the full regular expression.
     3.    Full regular expressions separated by | or by  a  new-
           line that match strings that are matched by any of the
           expressions.
     4.    A full regular expression  that  may  be  enclosed  in
           parentheses () for grouping.

     Be careful using the characters $, *, [, ^, |, (, ),  and  \
     in full regular expression, because they are also meaningful
     to the shell.  It is safest to enclose the entire full regu-
     lar expression in single quotes '...'.

     The order of precedence of operators is [], then  *?+,  then
     concatenation, then | and new-line.

     If no files are specified,  egrep  assumes  standard  input.
     Normally,  each line found is copied to the standard output.
     The file name is printed before each line found if there  is
     more than one input file.

     Command line options are:

     -b    Precede each line by the block number on which it  was
           found.   This  can be useful in locating block numbers
           by context (first block is 0).
     -c    Print only a count of the lines that contain the  pat-
           tern.
     -i    Ignore upper/lower case distinction  during  comparis-
           ons.



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egrep(1)                 USER COMMANDS                   egrep(1)



     -h    Suppress printing of filenames when searching multiple
           files.
     -l    Print the names of files  with  matching  lines  once,
           separated  by new-lines.  Does not repeat the names of
           files when the pattern is found more than once.
     -n    Precede each line by  its  line  number  in  the  file
           (first line is 1).
     -v    Print all lines except those that contain the pattern.
     -e special_expression
           Search for a special expression (full regular  expres-
           sion that begins with a -).
     -f file
           Take the list of full regular expressions from file.

SEE ALSO
     ed(1), fgrep(1), grep(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 (even if matches were
     found).

NOTES
     Ideally there should be only one grep command, but there  is
     not  a  single  algorithm  that spans a wide enough range of
     space-time tradeoffs.  Lines are limited to  BUFSIZ  charac-
     ters;  longer  lines  are  truncated.   BUFSIZ is defined in
     /usr/include/stdio.h.



























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