ed

commit 6846c4224dd3342c4cc67e08ac4910d44802b3ad
parent fec32b46a7e7f226df503b2c25b959ad7b3f59c8
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Tue,  1 Dec 2015 19:21:28 +0100

ed: improve regex/compile()

- use regerror for errors
- fix crash with input "/\n" (overflow, bp would be > cmdp).
- only match when compile() was successfull (WIP).

regex still has some bugs, more fixes coming soon.

Diffstat:
M
ed.c
 | 
28
++++++++++++++++------------

1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/ed.c b/ed.c
@@ -230,11 +230,13 @@ setscratch()
 	modflag = 0;
 }
 
-static void
+static int
 compile()
 {
+	static char regerrbuf[BUFSIZ];
 	char c, *bp, delim, buff[REGEXSIZE];
 	size_t len;
+	int ret;
 
 	for (delim = *cmdp++, bp = cmdp; c = *cmdp; ++cmdp) {
 		if (c == '\n')
@@ -242,21 +244,23 @@ compile()
 		if (c == '\n' || c == delim)
 			break;
 	}
-	if (!(len = cmdp - bp)) {
+	if (bp >= cmdp) {
 		if (!pattern)
 			error("no previous pattern");
-		return;
-	}
-	if (!pattern) {
-		if (!(pattern = malloc(sizeof(*pattern))))
-			error("no memory");
+		return 0;
 	}
+	if (!pattern && (!(pattern = malloc(sizeof(*pattern)))))
+		error("no memory");
+	len = cmdp - bp;
 	if (len >= sizeof(buff))
 		error("regular expression too long");
 	memcpy(buff, bp, len);
 	buff[len] = '\0';
-	if (regcomp(pattern, buff, 0))
-		error("incorrect regular expression"); /* TODO: call regerror */
+	if ((ret = regcomp(pattern, buff, REG_BASIC))) {
+		regerror(ret, pattern, regerrbuf, sizeof(regerrbuf));
+		error(regerrbuf);
+	}
+	return !ret;
 }
 
 static int
@@ -310,8 +314,8 @@ getnum(int *line)
 		sign = -sign;
 	case '/':
 		c = *cmdp;
-		compile();
-		ln = match(c);
+		if (compile())
+			ln = match(c);
 		break;
 	default:
 		if (isdigit(*cmdp)) {
@@ -896,7 +900,7 @@ chkglobal(void)
 		return 0;
 	}
 	deflines(nextln(0), lastln);
-	compile();
+	compile(); /* TODO: check compile */
 	++cmdp;          /* skip trailing '/' */
 
 	if (uflag)