regsub(n) Tcl Built-In Commands regsub(n)_________________________________________________________________NAMEregsub - Perform substitutions based on regular expression
pattern matching
SYNOPSISregsub ?switches? exp string subSpec varName
_________________________________________________________________DESCRIPTION
This command matches the regular expression exp against
string, and it copies string to the variable whose name is
given by varName. If there is a match, then while copying
string to varName the portion of string that matched exp
is replaced with subSpec. If subSpec contains a ``&'' or
``\0'', then it is replaced in the substitution with the
portion of string that matched exp. If subSpec contains a
``\n'', where n is a digit between 1 and 9, then it is
replaced in the substitution with the portion of string
that matched the n-th parenthesized subexpression of exp.
Additional backslashes may be used in subSpec to prevent
special interpretation of ``&'' or ``\0'' or ``\n'' or
backslash. The use of backslashes in subSpec tends to
interact badly with the Tcl parser's use of backslashes,
so it's generally safest to enclose subSpec in braces if
it includes backslashes.
If the initial arguments to regexp start with - then they
are treated as switches. The following switches are cur-
rently supported:
-all All ranges in string that match exp are found
and substitution is performed for each of these
ranges. Without this switch only the first
matching range is found and substituted. If
-all is specified, then ``&'' and ``\n''
sequences are handled for each substitution
using the information from the corresponding
match.
-nocase Upper-case characters in string will be con-
verted to lower-case before matching against
exp; however, substitutions specified by sub-
Spec use the original unconverted form of
string.
-- Marks the end of switches. The argument follow-
ing this one will be treated as exp even if it
starts with a -.
The command returns a count of the number of matching
ranges that were found and replaced. See the manual entry
Tcl 7.4 1
regsub(n) Tcl Built-In Commands regsub(n)
for regexp for details on the interpretation of regular
expressions.
KEYWORDS
match, pattern, regular expression, substitute
Tcl 7.4 2