rpmoffset: cleanup and remove size limit on cpio offsetv9.0.0.0g

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 30 insertions, 21 deletions

diff --git a/rpmoffset.c b/rpmoffset.c
index 524e310..32ccba2 100644
--- a/rpmoffset.c
+++ b/rpmoffset.c
@@ -4,29 +4,38 @@
 
 /* Wouldn't it be a lot more sane if we could just untar these things? */
 
+#include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
-/* These offsets keep getting bigger, so we're going to just bite a 2MB */
-/* chunk of RAM right away so that we have enough.  Yeah, horrible */
-/* quick and dirty implementation, but hey -- it gets the job done. */
+int main(int argc, char *argv[])
+{
+	size_t i;
+	char p[3];
 
-#define RPMBUFSIZ 2097152
+	if (argc != 1) {
+		puts("Usage: rpmoffset < rpmfile");
+		return 1;
+	}
 
-main()
-{
-        char *buff = malloc(RPMBUFSIZ),*eb,*p;
-        for (p = buff, eb = buff + read(0,buff,RPMBUFSIZ); p < eb; p++)
-        {
-                if (*p == '\037' && p[1] == '\213' && p[2] == '\010')
-                {
-                        printf("%d\n",p - buff);
-                        exit(0);
-                }
-                else if (*p == 'B' && p[1] == 'Z' && p[2] == 'h')
-                {
-                        printf("%d\n",p - buff);
-                        exit(0);
-                }
-        }
-        exit(1);
+	if (read(0,p,3) != 3)
+		return 2;
+
+	for (i = 0; p[2] != 0 || p[2] != -1; ++i) {
+		if (p[0] == '\037' && p[1] == '\213' && p[2] == '\010') {
+			printf("%zu\n", i);
+			return 0;
+
+		} else if (p[0] == 'B' && p[1] == 'Z' && p[2] == 'h') {
+			printf("%zu\n", i);
+			return 0;
+		}
+
+		p[0] = p[1];
+		p[1] = p[2];
+		if (read(0, p+2, 1) != 1)
+			return 2;
+	}
+
+	return 1;
 }