Use libedit when interacting with tty, which provided history

functionality, etc. as did by GNU bc.

This also fixes an issue where BSDL bc can not handle very long
line.

Reported by:	imp
Reviewed by:	imp

4 files changed, 65 insertions, 1 deletions

diff --git a/usr.bin/bc/Makefile b/usr.bin/bc/Makefile
index 17514ca..55f465d 100644
--- a/usr.bin/bc/Makefile
+++ b/usr.bin/bc/Makefile
@@ -5,6 +5,9 @@ PROG=	bc
 SRCS=	bc.y scan.l
 CFLAGS+= -I. -I${.CURDIR}
 
+DPADD=	${LIBEDIT} ${LIBTERMCAP}
+LDADD=	-ledit -ltermcap
+
 FILES+=	bc.library
 FILESDIR=${SHAREDIR}/misc
 
diff --git a/usr.bin/bc/bc.y b/usr.bin/bc/bc.y
index b00d140..b00d5ac 100644
--- a/usr.bin/bc/bc.y
+++ b/usr.bin/bc/bc.y
@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
 #include <err.h>
 #include <errno.h>
 #include <getopt.h>
+#include <histedit.h>
 #include <limits.h>
 #include <search.h>
 #include <signal.h>
@@ -1106,6 +1107,13 @@ sigchld(int signo)
 	}
 }
 
+static const char *
+dummy_prompt(void)
+{
+
+        return ("");
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -1173,6 +1181,16 @@ main(int argc, char *argv[])
 			dup(p[1]);
 			close(p[0]);
 			close(p[1]);
+			if (interactive) {
+				el = el_init("bc", stdin, stderr, stderr);
+				hist = history_init();
+				history(hist, &he, H_SETSIZE, 100);
+				el_set(el, EL_HIST, history, hist);
+				el_set(el, EL_EDITOR, "emacs");
+				el_set(el, EL_SIGNAL, 1);
+				el_set(el, EL_PROMPT, dummy_prompt);
+				el_source(el, NULL);
+			}
 		} else {
 			close(STDIN_FILENO);
 			dup(p[0]);
diff --git a/usr.bin/bc/extern.h b/usr.bin/bc/extern.h
index a99c46c..d1e9fe8 100644
--- a/usr.bin/bc/extern.h
+++ b/usr.bin/bc/extern.h
@@ -35,4 +35,8 @@ extern int		 sargc;
 extern const char	**sargv;
 extern const char	*filename;
 extern char		*cmdexpr;
-bool			 interactive;
+extern bool		 interactive;
+extern EditLine		*el;
+extern History		*hist;
+extern HistEvent	 he;
+
diff --git a/usr.bin/bc/scan.l b/usr.bin/bc/scan.l
index 81dd862..40f8ae6 100644
--- a/usr.bin/bc/scan.l
+++ b/usr.bin/bc/scan.l
@@ -22,6 +22,7 @@ __FBSDID("$FreeBSD$");
 
 #include <err.h>
 #include <errno.h>
+#include <histedit.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <string.h>
@@ -33,13 +34,22 @@ __FBSDID("$FreeBSD$");
 
 int		 lineno;
 
+bool		 interactive;
+HistEvent	 he;
+EditLine	*el;
+History		*hist;
+
 static char	*strbuf = NULL;
 static size_t	 strbuf_sz = 1;
 static bool	 dot_seen;
 
 static void	 init_strbuf(void);
 static void	 add_str(const char *);
+static int	 bc_yyinput(char *, int);
 
+#undef YY_INPUT
+#define YY_INPUT(buf,retval,max) \
+	(retval = bc_yyinput(buf, max))
 %}
 
 %option always-interactive
@@ -286,3 +296,32 @@ yywrap(void)
 	}
 	return (1);
 }
+
+static int
+bc_yyinput(char *buf, int maxlen)
+{
+	int num;
+	if (interactive) {
+		const char *bp;
+
+		if ((bp = el_gets(el, &num)) == NULL || num == 0)
+			return (0);
+		if (num > maxlen) {
+			el_push(el, (char *)(uintptr_t)(bp) + maxlen);
+			num = maxlen;
+		}
+		memcpy(buf, bp, num);
+		history(hist, &he, H_ENTER, bp);
+	} else {
+		int c = '*';
+		for (num = 0; num < maxlen &&
+		    (c = getc(yyin)) != EOF && c != '\n'; ++num)
+			buf[num] = (char) c;
+		if (c == '\n')
+			buf[num++] = (char) c;
+		if (c == EOF && ferror(yyin))
+			YY_FATAL_ERROR( "input in flex scanner failed" );
+	}
+	return (num);
+}
+