agrep —
print lines approximately matching a pattern
  
    | agrep | [options] pattern [files] | 
Searches for approximate matches of pattern in each
  FILE or standard input.
  - -epattern,- -- -regexp=pattern
- Use PATTERN as a regular expression; useful to
      protect patterns beginning with ‘-’.
- -i,- -- -ignore-case
- Ignore case distinctions (as defined by the current locale) in
      pattern and input files.
- -k,- -- -literal
- Treat pattern as a literal string, that is, a fixed
      string with no special characters.
- -w,- -- -word-regexp
- Force pattern to match only whole words. A
      “whole word” is a substring which either starts at the
      beginning or the record or is preceded by a non-word constituent
      character. Similarly, the substring must either end at the end of the
      record or be followed by a non-word constituent character.
      Word-constituent characters are alphanumerics (as defined by the current
      locale) and the underscore character. Note that the non-word constituent
      characters must surround the match; they cannot be
      counted as errors.
  - -#
- Select records that have at most # errors
      (# is a digit between 0 and 9).
- -Dnum,- -- -delete-cost=num
- Set cost of missing characters to num.
- -E- -num,- -- -max-errors=num
- Select records that have at most num errors.
- -Inum,- -- -insert-cost=num
- Set cost of extra characters to num.
- -Snum,- -- -substitue-cost=num
- Set cost of incorrect characters to num. Note that a
      deletion (a missing character) and an insertion (an extra character)
      together constitute a substituted character, but the cost will be the that
      of a deletion and an insertion added together. Thus, if the const of a
      substitution is set to be larger than the sum of the costs of deletion and
      insertion, direct substitutions will never be done.
  - -d- -pattern,- -- -delimiter=pattern
- Set the record delimiter regular expression to
      pattern. The text between two delimiters, before the
      first delimiter, and after the last delimiter is considered to be a
      record. The default record delimiter is the regexp “\n”, so
      by default a record is a line. pattern can be any
      regular expression that does not match the empty string. For example,
      using -dfile ... defines
      mail messages as records in a Mailbox format file.
- -- -help
- Display a brief help message and exit.
- -r,- -- -recursive
- If a directory is given as one of the command line arguments, look in
      every directory entry in the subdirectory, recursively.
- -V,- -- -version
- Print version information and exit.
- -v,- -- -invert-match
- Select non-matching records instead of matching records.
- -y,- -- -nothing
- Does nothing. This options exists only for compatibility with the non-free
      agrep program.
  - -B,- -- -best-match
- Only output the best matching records, that is, the records with the
      lowest cost. This is currently implemented by making two passes over the
      input files and cannot be used when reading from standard input.
- -- -color,- -- -colour
- Highlight the matching strings in the output with a color marker. The
      color string is taken from the GREP_COLORenvironment variable. The default color is red.
- -c,- -- -count
- Only print a count of matching records per each input file, suppressing
      normal output.
- -H,- -- -with-filename
- Prefix each output record with the name of the input file where the record
      was read from.
- -h,- -- -no-filename
- Suppress the prefixing filename on output when multiple files are
      searched.
- -l,- -- -files-with-matches
- Only print the name of each input file which contains at least one match,
      suppressing normal output. The scanning for each file will stop on the
      first match.
- -M,- -- -delimiter-after
- By default, the record delimiter is the newline character and is output
      after the matching record. If -dis used, the
      record delimiter will be output before the matching record. This option
      causes the delimiter to be output after the matching record.
- -n,- -- -record-number
- Prefix each output record with its sequence number in the input file. The
      number of the first record is 1.
- -q,- -- -quiet,- -- -silent
- Do not write anything to standard output. Exit immediately with zero exit
      status if a match is found.
- -s,- -- -show-cost
- Print match cost with output.
- -- -show-position
- Prefix each output record with the start and end offset of the first match
      within the record. The offset of the first character of the record is 0.
      The end position is given as the offset of the first character after the
      match.
With no file, or when
    file is “-”,
    agrep reads standard input. If less than two
    files are given -h is assumed,
    otherwise -H is the default.
agrep -2 optimize
  foo.txt
outputs all lines in file foo.txt that match
  “optimize” within two errors. E.g. lines which contain
  “optimise”, “optmise”, and
  “opitmize” all match.
Exit status is 0 if a match is found, 1 for no match, and 2 if there were
  errors. If -E or
  -# is not specified, only exact
  matches are selected.
pattern is a POSIX extended regular
    expression (ERE) with the TRE extensions.
Copyright © 2002-2004 Ville Laurikari.
This is free software, and comes with ABSOLUTELY NO WARRANTY. You
    are welcome to redistribute this software under certain conditions; see the
    source for the full license text.