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. (Regular
expression matching is described in the re_syntax reference page.) 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 substi‐
tution 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 back‐
slash. 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 currently supported:
-all All ranges in string that match exp are found and substitu‐
tion is performed for each of these ranges. Without this
switch only the first matching range is found and substi‐
tuted. 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 converted to lower-
case before matching against exp; however, substitutions
specified by subSpec use the original unconverted form of
string.
-- Marks the end of switches. The argument following 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 for regexp for details on the
interpretation of regular expressions.
KEYWORDS
match, pattern, regular expression, substitute
Tcl 7.4 regsub(n)
