Make RS as regexp work without ifdef. Add doc, bump version.

ChangeLog

@@ -1,3 +1,11 @@
+2019-10-06         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* lib.c (readrec): Allow RS a regular expression. Imported
+	the code from the NetBSD awk.
+	* b.c (fnematch): New function for implementing the feature.
+	* awk.1: Updated.
+	* main.c (version): Updated.
+
 2019-06-24         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* makefile: Revise to take into account there is no more awktest.tar,
@@ -18,7 +26,7 @@
 	* b.c (relex): Count parentheses and treat umatched right paren
 	as a literal character.
 	* awktest.tar (testdir/T.re): Added a test case.
-	* main.c (version): Upated.
+	* main.c (version): Updated.
 
 2019-05-29         Arnold D. Robbins     <arnold@skeeve.com>
 

FIXES

@@ -25,6 +25,10 @@ THIS SOFTWARE.
 This file lists all bug fixes, changes, etc., made since the AWK book
 was sent to the printers in August, 1987.
 
+October 6, 2019:
+	Import code from NetBSD awk that implements RS as a regular
+	expression.
+
 September 10, 2019:
 	Fixes for various array / memory overruns found via gcc's
 	-fsanitize=unknown. Thanks to Alexander Richardson (Github

awk.1

@@ -478,6 +478,11 @@ the length of a string matched by
 .TP
 .B RS
 input record separator (default newline).
+If empty, blank lines separate records.
+If more than one character long,
+.B RS
+is treated as a regular expression, and records are
+separated by text matching the expression.
 .TP
 .B RSTART
 the start position of a string matched by

lib.c

@@ -209,7 +209,6 @@ int readrec(char **pbuf, int *pbufsize, FILE *inf)	/* read one record into buf *
 	int bufsize = *pbufsize;
 	char *rs = getsval(rsloc);
 
-#ifdef RS_AS_REGEXP
 	if (*rs && rs[1]) {
 		int found;
 
@@ -218,7 +217,6 @@ int readrec(char **pbuf, int *pbufsize, FILE *inf)	/* read one record into buf *
 		if (found)
 			*patbeg = 0;
 	} else {
-#endif
 		if ((sep = *rs) == 0) {
 			sep = '\n';
 			while ((c=getc(inf)) == '\n' && c != EOF)	/* skip leading \n's */
@@ -247,9 +245,7 @@ int readrec(char **pbuf, int *pbufsize, FILE *inf)	/* read one record into buf *
 		if (!adjbuf(&buf, &bufsize, 1+rr-buf, recsize, &rr, "readrec 3"))
 			FATAL("input record `%.30s...' too long", buf);
 		*rr = 0;
-#ifdef RS_AS_REGEXP
 	}
-#endif
 	*pbuf = buf;
 	*pbufsize = bufsize;
 	isrec = *buf || !feof(inf);

main.c

@@ -22,7 +22,7 @@ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
 THIS SOFTWARE.
 ****************************************************************/
 
-const char	*version = "version 20190910";
+const char	*version = "version 20191006";
 
 #define DEBUG
 #include <stdio.h>