SSED USAGE

   ssed (super-sed) is a customized version of GNU sed which supports
   Perl-style regular expressions and features in its commands for
   s/ubstitu/tion/ and /addressing/. ssed is maintained by Paolo
   Bonzini (bonzini@gnu.org). The latest version of ssed can always be
   found here, on the ssed home page:

   http://spazioweb.inwind.it/seders/ssed/

   An alternate location, with ssed compiled for Win32, is usually at
   http://www.student.northpark.edu/pemente/sed/index.htm

A summary of features supported in ssed:

(1) Can be used in /addressing/ or on the FIND side of s/// commands:

     \`  - matches the beginning of the pattern space: same as "^"
     \'  - matches the end of the pattern space: same as "$"
     \?  - 0 or 1 occurrences of previous char: same as \{0,1\}
     \+  - 1 or more occurrences of previous char: same as \{1,\}
     \|  - matches the string on either side, e.g., foo\|bar
     \b  - boundary between word and nonword chars (reversible)
     \B  - boundary between 2 word or between 2 nonword chars
     \n  - embedded newline (usable after N, G, or similar commands)
     \s  - any whitespace character [space, TAB, VT, FF, \n]
     \S  - any non-whitespace character
     \w  - any word character: same as [A-Za-z0-9_]
     \W  - any nonword char: same as [^A-Za-z0-9_]
     \<  - boundary between nonword & word char (except in Perl-mode)
     \>  - boundary between word & nonword char (except in Perl-mode)

     \(...\) - used for grouping; use ( or ) for literal parentheses
     \{M,N\} - used for interval exps.; use { or } for literal braces

(2) Supported for -r (extended regex) or -R (Perl-mode). NOTE: the -r 
    switch is an undocumented option in GNU sed v3.02+.

     (...) - used for grouping; use \( or \) for literal parentheses
     {M,N} - used for interval exps.; use \{ or \} for literal braces
     ?     - zero or one, instead of \?
     +     - one or more, instead of \+
     |     - alternation, instead of \|

(3) Can be used in /addressing/ or on EITHER side of an s/// cmd:

     \a    - "alert" beep     (BEL, Ctrl-G, 0x07)
     \f    - formfeed         (FF,  Ctrl-L, 0x0C)
     \n    - newline          (LF,  Ctrl-J, 0x0A)
     \r    - carriage-return  (CR,  Ctrl-M, 0x0D)
     \t    - horizontal tab   (HT,  Ctrl-I, 0x09)
     \v    - vertical tab     (VT,  Ctrl-K, 0x0B)
     \cx   - Ctrl-X (\cb is Ctrl-B, \cP is Ctrl-P, \cV is Ctrl-V, etc.)
     \oNNN - character with the octal value NNN (except in Perl-mode)
     \dNNN - character with the decimal value NNN (except in Perl-mode)
     \xNN  - character with the hexadecimal value NN

(4) Case conversion, used only on the REPLACE side of an s/// command:

     \l  - convert next char to lowercase
     \L  - convert rest of line to lowercase
     \u  - convert next char to uppercase
     \U  - convert rest of line to uppercase
     \E  - end case conversion begun by \L or \U

(5) In Perl-mode (-R switch), these become active or inactive:

     \A    - matches beginning of pattern space
     \Z    - matches end of pattern space or last newline in the PS
     \z    - matches end of pattern space
     \d    - matches any digit: same as [0-9]
     \D    - matches any non-digit: same as [^0-9]
     \`    - no longer matches beginning of pattern space
     \'    - no longer matches end of pattern space
     \<    - no longer matches boundary between nonword & word char
     \>    - no longer matches boundary between word & nonword char
     \oNNN - no longer matches char with octal value NNN
     \dNNN - no longer matches char with decimal value NNN

(6) New switches in /addressing/ or s/// commands. Switches may be
    lowercase in s/// cmds, but must be uppercase in /addressing/.

   /I  - ignore case in FIND patterns
   /M  - multi-line patterns: ^ or $ will match BOL or EOL
   /S  - Perl-mode ONLY: lets "." match a newline also
   /X  - Perl-mode ONLY: extra whitespace is ignored. See section (9),
         below, for sample usage.

(7) Perl-style regular expressions, with examples. Use the -R switch.
    Used in /addressing/ or the FIND side of s/// commands.

  (?i)abc   - case-insensitive match of abc, ABC, aBc, ABc, etc.
  ab(?i)c   - same as above; the (?i) applies throughout the pattern
  (ab(?i)c) - matches abc or abC; the outer parens make the difference!
  (?m)      - multi-line pattern space: same as "s/FIND/REPL/M"
  (?s)      - set "." to match newline also: same as "s/FIND/REPL/S"
  (?x)      - ignore whitespace and #comments; see section (9) below.
  (?:abc)foo   - match "abcfoo", but do not capture 'abc' in \1
  (?:ab|cd)ef  - match "abef" or "cdef"; only 'cd' is captured in \1
  (?#remark)xy - match "xy"; remarks after "#" are ignored.

(8) Lookahead (?=match) and lookbehind (?<match) pattern matching.
    NB: the matched text is NOT captured in "&" for s/// replacements!

  foo(?=bar)   - match "foo" only if "bar" follows it
  foo(?!bar)   - match "foo" only if "bar" does NOT follow it
  (?<=foo)bar  - match "bar" only if "foo" precedes it
  (?<!foo)bar  - match "bar" only if "foo" does NOT precede it

  (?<!in|on|at)foo
     - match "foo" only if NOT preceded by "in", "on" or "at"

  (?<=\d{3})(?<!999)foo
     - match "foo" only if preceded by 3 digits other than "999"

(9) Sample use of /X switch to add comments to complex expressions.
    To embed literal spaces, precede with \ or put inside [brackets].

    # ssed script to change "(123) 456-7890" into "[ac123] 456-7890"
    #
    s/                # BACKSLASH IS NEEDED AT END OF EACH LINE!  \
      \(              # literal left paren, (                     \
      (\d{3})         # 3 digits                                  \
      \)              # literal right paren, )                    \
      [ \t]*          # zero or more spaces or tabs               \
      (\d{3}-\d{4})   # 3 digits, hyphen, 4 digits                \
    /[ac\1] \2/gx;    # replace g(lobally), with x(tended spacing)
    #
    # end of script

summary written by Eric Pement - pemente@northpark.edu
last updated: 23 March 2001

[eof]