sbase

commit e1f87da43e4805ac6758fa11cc49fbebaa5c3c89
parent 0e8a8c942667547fb99fbdcfe19b5fa5dbfa22a8
Author: Michael Forney <mforney@mforney.org>
Date:   Sat,  1 Nov 2014 20:36:40 +0000

tar: Handle archives with the prefix field

Also, handle names and prefixes that fill the entire field (and have no
NUL byte) by using a precision specifier.

Diffstat:
M
tar.c
 | 
8
++++++--

1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/tar.c b/tar.c
@@ -27,6 +27,7 @@ struct Header {
 	char gname[32];
 	char major[8];
 	char minor[8];
+	char prefix[155];
 };
 
 enum {
@@ -298,11 +299,14 @@ c(const char * path)
 static void
 xt(int (*fn)(char*, int, char[Blksiz]))
 {
-	char b[Blksiz], fname[101];
+	char b[Blksiz], fname[257], *s;
 	Header *h = (void*)b;
 
 	while(fread(b, Blksiz, 1, tarfile) && h->name[0] != '\0') {
-		snprintf(fname, sizeof fname, "%s", h->name);
+		s = fname;
+		if (h->prefix[0] != '\0')
+			s += sprintf(s, "%.*s/", (int)sizeof h->prefix, h->prefix);
+		sprintf(s, "%.*s", (int)sizeof h->name, h->name);
 		fn(fname, strtol(h->size, 0, 8), b);
 	}
 }