Hi,
Our dd always prints these status lines to stderr after transfer.
2+0 records in
2+0 records out
1024 bytes transferred in 0.000 secs (39384615 bytes/sec)
The output is annoying in some situations, so people redirect stderr
to /dev/null. This approach also suppresses the error messages and
bugs in shell scripts remain undetected.
GNU dd has the status=noxfer and status=none switch to make it
quiet. Their status=none disables some more warnings, we can add
that later if we want.
I would like to get rid of some 2>/dev/null.
Do we want the status=... feature in OpenBSD?
bluhm
Index: bin/dd/args.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/bin/dd/args.c,v
retrieving revision 1.21
diff -u -p -u -p -r1.21 args.c
--- bin/dd/args.c 11 Nov 2013 23:07:28 -0000 1.21
+++ bin/dd/args.c 9 Feb 2014 09:21:54 -0000
@@ -59,6 +59,7 @@ static void f_obs(char *);
static void f_of(char *);
static void f_seek(char *);
static void f_skip(char *);
+static void f_status(char *);
static size_t get_bsz(char *);
static off_t get_off(char *);
@@ -78,6 +79,7 @@ static const struct arg {
{ "of", f_of, C_OF, C_OF },
{ "seek", f_seek, C_SEEK, C_SEEK },
{ "skip", f_skip, C_SKIP, C_SKIP },
+ { "status", f_status, C_STATUS,C_STATUS },
};
static char *oper;
@@ -247,6 +249,18 @@ f_skip(char *arg)
{
in.offset = get_off(arg);
+}
+
+static void
+f_status(char *arg)
+{
+
+ if (strcmp(arg, "none") == 0)
+ ddflags |= C_NOINFO;
+ else if (strcmp(arg, "noxfer") == 0)
+ ddflags |= C_NOXFER;
+ else
+ errx(1, "unknown status %s", arg);
}
Index: bin/dd/dd.1
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/bin/dd/dd.1,v
retrieving revision 1.26
diff -u -p -u -p -r1.26 dd.1
--- bin/dd/dd.1 2 Feb 2014 22:43:40 -0000 1.26
+++ bin/dd/dd.1 9 Feb 2014 09:56:55 -0000
@@ -139,6 +139,21 @@ For all other devices, the correct numbe
distinguishing between a partial or complete block being read.
.It Xo
.Sm off
+.Cm status= Ar value
+.Sm on
+.Xc
+Where
+.Ar value
+is one of the symbols from the following list.
+.Bl -tag -width unblock
+.It Cm noxfer
+Do not print the transfer statistics as the last line of status output.
+.It Cm none
+Do not print the status output.
+Error messages are shown, but no informational messages.
+.El
+.It Xo
+.Sm off
.Cm conv= Ar value Oo ,
.Sm on
.Ar value ... Oc
Index: bin/dd/dd.h
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/bin/dd/dd.h,v
retrieving revision 1.5
diff -u -p -u -p -r1.5 dd.h
--- bin/dd/dd.h 2 Jun 2003 23:32:07 -0000 1.5
+++ bin/dd/dd.h 9 Feb 2014 09:16:03 -0000
@@ -93,3 +93,6 @@ typedef struct {
#define C_UCASE 0x40000
#define C_UNBLOCK 0x80000
#define C_OSYNC 0x100000
+#define C_STATUS 0x200000
+#define C_NOXFER 0x400000
+#define C_NOINFO 0x800000
Index: bin/dd/misc.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/bin/dd/misc.c,v
retrieving revision 1.17
diff -u -p -u -p -r1.17 misc.c
--- bin/dd/misc.c 16 Apr 2013 22:13:43 -0000 1.17
+++ bin/dd/misc.c 9 Feb 2014 09:27:25 -0000
@@ -58,6 +58,9 @@ summary(void)
double microsecs;
int i = 0;
+ if (ddflags & C_NOINFO)
+ return;
+
(void)gettimeofday(&nowtv, (struct timezone *)NULL);
timersub(&nowtv, &st.startv, &nowtv);
microsecs = ((double)nowtv.tv_sec * 1000000) + nowtv.tv_usec;
@@ -85,13 +88,15 @@ summary(void)
iov[i].iov_base = buf[2];
iov[i++].iov_len = strlen(buf[2]);
}
- (void)snprintf(buf[3], sizeof(buf[3]),
- "%qd bytes transferred in %lld.%03ld secs (%0.0f bytes/sec)\n",
- (long long)st.bytes, (long long)nowtv.tv_sec, nowtv.tv_usec / 1000,
- ((double)st.bytes * 1000000) / microsecs);
-
- iov[i].iov_base = buf[3];
- iov[i++].iov_len = strlen(buf[3]);
+ if (!(ddflags & C_NOXFER)) {
+ (void)snprintf(buf[3], sizeof(buf[3]),
+ "%qd bytes transferred in %lld.%03ld secs "
+ "(%0.0f bytes/sec)\n", (long long)st.bytes,
+ (long long)nowtv.tv_sec, nowtv.tv_usec / 1000,
+ ((double)st.bytes * 1000000) / microsecs);
+ iov[i].iov_base = buf[3];
+ iov[i++].iov_len = strlen(buf[3]);
+ }
(void)writev(STDERR_FILENO, iov, i);
}
