From: Nick Bowler <nbowler@draconx.ca>
Date: Sun, 10 Jul 2011 16:25:37 +0000 (-0400)
Subject: Split up interactive/noninteractive loops.
X-Git-Tag: v1~137
X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/commitdiff_plain/2477f65ab0567a1b2c1c7e33cd7b66f19fd8ea2d

Split up interactive/noninteractive loops.

Readline isn't well suited for non-interactive loops since it tends to
print stuff to standard output.  So use two loops: a readline-based one
and a getline-based one.
---

diff --git a/src/cdecl99.c b/src/cdecl99.c
index 44bcd3e..667ae03 100644
--- a/src/cdecl99.c
+++ b/src/cdecl99.c
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
+#include <errno.h>
 #include <getopt.h>
 #include "readline.h"
 #include "cdecl.h"
@@ -180,47 +181,74 @@ static int cmd_help(char *cmd, char *arg)
 	return 1;
 }
 
-static int repl(bool interactive)
+static int run_command(char *line)
 {
-	char *prompt = interactive ? "> " : NULL;
-	int rc, ret = 0;
-	char *line;
+	char *cmd = line + strspn(line, " \t");
+	char *arg = cmd  + strcspn(cmd, " \t");
 
-	for (; (line = readline(prompt)); free(line)) {
-		char *cmd = line + strspn(line, " \t");
-		char *arg = cmd  + strcspn(cmd, " \t");
+	if (cmd[0] == '\0')
+		return 1;
+	if (arg[0] != '\0')
+		*arg++ = '\0';
 
-		if (cmd[0] == '\0')
+	for (size_t i = 0; i < ncommands; i++) {
+		if (strcmp(cmd, commands[i].name) != 0)
 			continue;
-		if (arg[0] != '\0')
-			*arg++ = '\0';
-
-		for (size_t i = 0; i < ncommands; i++) {
-			if (strcmp(cmd, commands[i].name) != 0)
-				continue;
-
-			rc = commands[i].func(cmd, arg);
-			if (!interactive && rc < 0)
-				ret = -1;
-			if (rc == 0)
-				goto out;
-			goto next;
-		}
 
-		fprintf(stderr, "Undefined command: %s\n", cmd);
-		ret = -1;
-	next:
-		;
+		return commands[i].func(cmd, arg);
 	}
-out:
+
+	fprintf(stderr, "Undefined command: %s\n", cmd);
+	return -1;
+}
+
+static int repl(void)
+{
+	char *line;
+
+	for (; (line = readline("> ")); free(line)) {
+		if (!run_command(line))
+			break;
+	}
+
 	free(line);
+	return 0;
+}
+
+static int repl_noninteractive(void)
+{
+	int rc, ret = 0, saved_errno;
+	char *line = NULL;
+	size_t n;
+
+	while (getline(&line, &n, stdin) >= 0) {
+		char *c = strchr(line, '\n');
+		if (c)
+			*c = '\0';
+
+		rc = run_command(line);
+		if (rc < 0)
+			ret = -1;
+		else if (rc == 0)
+			break;
+	}
+
+	saved_errno = errno;
+	free(line);
+
+	if (ferror(stdin)) {
+		errno = saved_errno;
+		perror("read error");
+		return -1;
+	}
+
 	return ret;
 }
 
 int main(int argc, char **argv)
 {
 	bool show_intro = true, interactive = true;
-	int opt;
+	int opt, rc;
 
 	if (argc > 0)
 		progname = argv[0];
@@ -251,8 +279,12 @@ int main(int argc, char **argv)
 	if (interactive && show_intro)
 		print_version();
 
-	if (repl(interactive) != 0)
-		return EXIT_FAILURE;
+	if (interactive)
+		rc = repl();
+	else
+		rc = repl_noninteractive();
 
+	if (rc != 0)
+		return EXIT_FAILURE;
 	return EXIT_SUCCESS;
 }