9os

commit f82f4e89c15cfb1b8f019d6710ba40dce50609bf
parent 9c8d68280c9f248f7f1772a709a0910740e1fca8
Author: Roberto E. Vargas Caballero <roberto.vargas@midokura.com>
Date:   Tue, 15 Nov 2022 20:15:45 +0100

os9: Improve getline() error handling

Previous version didn't differentiate between end of file
and some other error. Also, the interface didn't allow to
detect truncations.

Diffstat:
M
src/libk/getline.c
 | 
15
+++++++--------
M
src/os9/sys.c
 | 
21
+++++++++++++++------

2 files changed, 22 insertions(+), 14 deletions(-)
diff --git a/src/libk/getline.c b/src/libk/getline.c
@@ -5,18 +5,17 @@
 int
 getline(Chan *c, char *line, int size)
 {
-	int n;
+	int n, r;
 	char ch;
 
-	for (n = 0; n < size-1; ++n) {
-		if (devread(c, &ch, 1) < 0)
+	for (ch = n = 0; n < size-1 && ch != '\n'; ++n) {
+		if ((r = devread(c, &ch, 1)) < 0)
 			return -1;
+		if (r == 0)
+			break;
 		line[n] = ch;
-		if (ch == '\n') {
-			line[n+1] = '\0';
-			return n;
-		}
 	}
+	line[n] = '\0';
 
-	return -1;
+	return n;
 }
diff --git a/src/os9/sys.c b/src/os9/sys.c
@@ -63,6 +63,7 @@ mountline(char *line)
 static void
 iconf(void)
 {
+	int n;
 	Chan *c;
 	char line[80], *s, *p;
 
@@ -71,7 +72,11 @@ iconf(void)
 		return;
 	}
 
-	while (getline(c, line, sizeof(line)) > 0) {
+	while ((n = getline(c, line, sizeof(line))) > 0) {
+		if (line[n-1] != '\n') {
+			kprint("iconf: truncated configuration line\n");
+			continue;
+		}
 		for (p = line; isspace(*p); ++p)
 			;
 		s = p;
@@ -80,15 +85,19 @@ iconf(void)
 		while (isspace(*p))
 			*p++ = '\0';
 
-		if (strcmp(s, "write") == 0)
+		if (strcmp(s, "write") == 0) {
 			writeline(p);
-		else if (strcmp(s, "bind") == 0)
+		} else if (strcmp(s, "bind") == 0) {
 			bindline(p);
-		else if (strcmp(s, "mount") == 0)
+		} else if (strcmp(s, "mount") == 0) {
 			mountline(p);
-		else
-			panic("iconf:verb");
+		} else {
+			kprint("iconf: incorrect verb '%s'\n", s);
+			continue;
+		}
 	}
+	if (n < 0)
+		kprint("iconf: error reading configuration:%r\n");
 
 	devclose(c);
 }