* The interface also provides many convenience functions to make the use
* of regular expressions easier. Especially the silc_regex allows very
* simple way to match strings against regular expressions and get the
- * exact match or matches as a return.
+ * exact match or matches as a return. The silc_subst provides simple and
+ * familiar way to match and substitute strings (Sed syntax).
*
* The regex syntax follows POSIX regex syntax:
*
* The first (whole) match is returned to `match' buffer if it is non-NULL.
* The variable argument list are buffers where multiple matches are
* returned in case of group (parenthesized) regular expression. The caller
- * needs to know how many pointers to provide, in order to get all matches.
+ * needs to know how many pointers to provide in order to get all matches.
+ * If a particular group is optional, a buffer pointer still must be given
+ * as argument for it, however, if it did not match the returned buffer
+ * length is 0 and data pointer is NULL.
+ *
* If `match' is non-NULL the variable argument list must be ended with
* NULL. The data in the `match' and in any other buffer is from `string'
* and must not be freed by the caller.
SilcBool silc_regex_buffer(SilcBuffer buffer, const char *regex,
SilcBuffer match, ...);
+/****f* silcutil/SilcRegexAPI/silc_subst
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_subst(SilcBuffer buffer, const char *subst);
+ *
+ * DESCRIPTION
+ *
+ * Regular expression matching and substitution in `buffer' according
+ * to the substitution expression `subst'. This function provides
+ * Sed (Stream Editor) style substitution interface. The `subst' may
+ * be of following formats:
+ *
+ * 's/REGEXP/REPLACEMENT/FLAGS'
+ *
+ * Matches regular expression REGEXP in each line in the buffer and
+ * substitutes the match with REPLACEMENT.
+ *
+ * 'ADDRs/REGEXP/REPLACEMENT/FLAGS'
+ *
+ * Selects lines in the buffer matching the address ADDR and matches the
+ * regular expression REGEXP in the line and substitutes the match with
+ * REPLACEMENT.
+ *
+ * The ADDR may be of following format:
+ *
+ * /REGEXP/ Matches only lines matching the regular expression
+ * NUMBER Matches only the specified line number (1-n)
+ * $ Matches only the last line
+ *
+ * The FLAGS may be of following format:
+ *
+ * no FLAGS Finds first match in the line and replaces that
+ * g Finds and replaces all matches in the line
+ *
+ * An '!' may precede the 's'. In that case the ADDR is not matched.
+ *
+ * Returns TRUE if the match and replacement was done, FALSE in case
+ * of error, and sets the silc_errno.
+ *
+ * If you need to match and/or replace '/' characters, they must be
+ * escaped with '\' (C-style escaping for '\' is '\\').
+ *
+ * If you need more versatile ways to modify the buffer you may consider
+ * using the SILC_STR_REGEX in SILC Buffer Format API directly. This
+ * function only provides basic matching and substitution.
+ *
+ * EXAMPLE
+ *
+ * // Replace all foos with bar on all lines in the buffer
+ * silc_subst(buffer, "s/foo/bar/g");
+ *
+ ***/
+SilcBool silc_subst(SilcBuffer buffer, const char *subst);
+
/* Backwards support */
#define silc_string_regex_match(regex, string) silc_regex(string, regex, NULL)