From 81af33db3056d7f49917f103307bc7d427fe4157 Mon Sep 17 00:00:00 2001
From: Thadeu Lima de Souza Cascardo <cascardo@cascardo.eti.br>
Date: Sat, 10 Dec 2016 11:21:21 -0200
Subject: [PATCH] Adiciona suporte a readline.
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Quando executado sem um parâmetro, o declara aceitará comandos na
entrada padrão, utilizando readline e history.
---
 configure.ac  |  4 ++++
 src/declara.c | 53 +++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7e84526..0cea681 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,5 +9,9 @@ dnl Checking for zlib.
 AC_SEARCH_LIBS([crc32], [z], [],
         AC_MSG_ERROR([could not find zlib]))
 
+dnl Checking for readline
+AC_SEARCH_LIBS([readline], [readline], [],
+	AC_MSG_ERROR([could not find readline]))
+
 AC_CONFIG_HEADERS([config.h])
 AC_OUTPUT(Makefile lib/Makefile src/Makefile test/Makefile)
diff --git a/src/declara.c b/src/declara.c
index 6f6a741..54e1abb 100644
--- a/src/declara.c
+++ b/src/declara.c
@@ -23,6 +23,9 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <readline/readline.h>
+#include <readline/history.h>
+
 #include "declaracao.h"
 #include "cmd.h"
 #include "base.h"
@@ -36,7 +39,9 @@
 #include "calcula.h"
 #include "gera.h"
 
-static int realprocess(struct declaracao *dec, int fd)
+static int readline_support = 1;
+
+static int fileprocess(struct declaracao *dec, int fd)
 {
 	char *line = NULL;
 	size_t lsz = 0;
@@ -58,6 +63,24 @@ static int realprocess(struct declaracao *dec, int fd)
 	return r;
 }
 
+static int ttyprocess(struct declaracao *dec)
+{
+	char *line = NULL;
+	int r;
+	using_history();
+	while ((line = readline("declara> ")) != NULL) {
+		if (*line)
+			add_history(line);
+		r = cmd_run(dec, line);
+		if (r < 0) {
+			fprintf(stderr, "Não foi possível executar comando: %s\n",
+				strerror(-r));
+		}
+		free(line);
+	}
+	return r;
+}
+
 static int process(char *filename)
 {
 	int r = 0;
@@ -66,13 +89,21 @@ static int process(char *filename)
 	dec = declaracao_new(-1);
 	if (!dec)
 		return -errno;
-	fd = open(filename, O_RDONLY);
-	if (fd < 0) {
-		r = -errno;
-		goto out_open;
+	if (filename != NULL) {
+		fd = open(filename, O_RDONLY);
+		if (fd < 0) {
+			r = -errno;
+			goto out_open;
+		}
+		r = fileprocess(dec, fd);
+		close(fd);
+	} else {
+		if (isatty(0) && readline_support) {
+			r = ttyprocess(dec);
+		} else {
+			r = fileprocess(dec, 0);
+		}
 	}
-	realprocess(dec, fd);
-	close(fd);
 out_open:
 	declaracao_free(dec);
 	return r;
@@ -86,9 +117,9 @@ static void usage(void)
 
 int main(int argc, char **argv)
 {
-	char *filename;
+	char *filename = NULL;
 	int r;
-	if (argc < 2)
+	if (!readline_support && argc < 2)
 		usage();
 
 	cmd_init();
@@ -104,9 +135,11 @@ int main(int argc, char **argv)
 	gera_cmd_init();
 	sistema_cmd_init();
 
-	filename = argv[1];
+	if (argc > 1)
+		filename = argv[1];
 	r = process(filename);
 	if (r)
 		return 1;
+
 	return 0;
 }
-- 
2.20.1