Support noerror option

2 files changed, 18 insertions, 4 deletions

diff --git a/coreutils/dd.c b/coreutils/dd.c
index 09e6cccc7..fb78d5355 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -46,7 +46,7 @@ static const struct suffix_mult dd_suffixes[] = {
 
 int dd_main(int argc, char **argv)
 {
-        int i, ifd, ofd, oflag, sync_flag = FALSE, trunc = TRUE;
+        int i, ifd, ofd, oflag, sync_flag = FALSE, trunc = TRUE, noerror = FALSE;
         size_t in_full = 0, in_part = 0, out_full = 0, out_part = 0;
         size_t bs = 512, count = -1;
         ssize_t n;
@@ -75,6 +75,9 @@ int dd_main(int argc, char **argv)
                                 } else if (strncmp("sync", buf, 4) == 0) {
                                         sync_flag = TRUE;
                                         buf += 4;
+                                } else if (strncmp("noerror", buf, 7) == 0) {
+                                        noerror = TRUE;
+                                        buf += 7;
                                 } else {
                                         error_msg_and_die("invalid conversion `%s'", argv[i]+5);
                                 }
@@ -131,9 +134,19 @@ int dd_main(int argc, char **argv)
         }
 
         while (in_full + in_part != count) {
+                if (noerror) {
+                        /* Pre-zero the buffer when doing the noerror thing */
+                        memset(buf, '\0', bs);
+                }
                 n = safe_read(ifd, buf, bs);
-                if (n < 0)
-                        perror_msg_and_die("%s", infile);
+                if (n < 0) {
+                        if (noerror) {
+                                n = bs;
+                                perror_msg("%s", infile);
+                        } else {
+                                perror_msg_and_die("%s", infile);
+                        }
+                }
                 if (n == 0)
                         break;
                 if (n == bs)
diff --git a/include/usage.h b/include/usage.h
index ad34dfcff..d0f3dfc99 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -228,7 +228,7 @@
 
 #define dd_trivial_usage \
         "[if=FILE] [of=FILE] [bs=N] [count=N] [skip=N]\n" \
-        "\t  [seek=N] [conv=notrunc|sync]"
+        "\t  [seek=N] [conv=notrunc|noerror|sync]"
 #define dd_full_usage \
         "Copy a file, converting and formatting according to options\n\n" \
         "\tif=FILE\t\tread from FILE instead of stdin\n" \
@@ -238,6 +238,7 @@
         "\tskip=N\t\tskip N input blocks\n" \
         "\tseek=N\t\tskip N output blocks\n" \
         "\tconv=notrunc\tdon't truncate output file\n" \
+        "\tconv=noerror\tcontinue after read errors\n" \
         "\tconv=sync\tpad blocks with zeros\n" \
         "\n" \
         "Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),\n" \