Patch from Laurence Anderson <L.D.Anderson@warwick.ac.uk> for

better tape drive support in tar/cpio by using an intervening
pipe...

2 files changed, 25 insertions, 1 deletions

diff --git a/archival/config.in b/archival/config.in
index 7b5644f01..5a064dc89 100644
--- a/archival/config.in
+++ b/archival/config.in
@@ -20,5 +20,8 @@ if [ "$CONFIG_TAR" = "y" ] ; then
     bool '  Enable -X and --exclude options (exclude files)'    CONFIG_FEATURE_TAR_EXCLUDE
     bool '  Enable -z option (currently only for extracting)'   CONFIG_FEATURE_TAR_GZIP
 fi
+if [ "$CONFIG_CPIO" = "y" -o "$CONFIG_TAR" = "y" ] ; then
+    bool '  Enable tape drive support' CONFIG_FEATURE_UNARCHIVE_TAPE
+fi
 bool 'unzip'        CONFIG_UNZIP
 endmenu
diff --git a/archival/libunarchive/unarchive.c b/archival/libunarchive/unarchive.c
index 41be963ef..49908affb 100644
--- a/archival/libunarchive/unarchive.c
+++ b/archival/libunarchive/unarchive.c
@@ -21,8 +21,10 @@
 #include <string.h>
 #include <unistd.h>
 #include <utime.h>
+#include <sys/wait.h>
+#include <signal.h>
 #include "unarchive.h"
-#include "libbb.h"
+#include "busybox.h"
 
 /* Extract the data postioned at src_stream to either filesystem, stdout or 
  * buffer depending on the value of 'function' which is defined in libbb.h 
@@ -202,7 +204,22 @@ char *unarchive(FILE *src_stream, FILE *out_stream, file_header_t *(*get_headers
         int extract_flag = TRUE;
         int i;
         char *buffer = NULL;
+#ifdef CONFIG_FEATURE_UNARCHIVE_TAPE
+        int pid, tape_pipe[2];
 
+        if (pipe(tape_pipe) != 0) error_msg_and_die("Can't create pipe\n");
+        if ((pid = fork()) == -1) error_msg_and_die("Fork failed\n");
+        if (pid==0) { /* child process */
+            close(tape_pipe[0]); /* We don't wan't to read from the pipe */
+            copyfd(fileno(src_stream), tape_pipe[1]);
+            close(tape_pipe[1]); /* Send EOF */
+            exit(0);
+            /* notreached */
+        }
+        close(tape_pipe[1]); /* Don't want to write down the pipe */
+        fclose(src_stream);
+        src_stream = fdopen(tape_pipe[0], "r");
+#endif
         archive_offset = 0;
         while ((file_entry = get_headers(src_stream)) != NULL) {
 
@@ -238,5 +255,9 @@ char *unarchive(FILE *src_stream, FILE *out_stream, file_header_t *(*get_headers
                 free(file_entry->link_name);
                 free(file_entry);
         }
+#ifdef CONFIG_FEATURE_UNARCHIVE_TAPE
+        kill(pid, SIGTERM);
+        waitpid(pid, NULL, 0);
+#endif
         return(buffer);
 }