dd(1) casts many of its numeric arguments from uintmax_t to intmax_t
and back again to detect whether or not the original arguments were
negative. This caused wrong behaviour in some boundary cases:
$ dd if=/dev/zero of=/dev/null count=18446744073709551615
dd: count cannot be negative
After the fix:
$ dd if=/dev/zero of=/dev/null count=18446744073709551615
dd: count: Result too large
PR: 191263
Submitted by: will@worrbase.com
Approved by: cognet@
* Don't use sysexits.h. Just exit 1 on error and 0 otherwise.
* Don't sacrifice precision by converting the output of clock_gettime() to a
double and then comparing the results. Instead, subtract the values of
the two clock_gettime() calls, then convert to double.
* Don't use CLOCK_MONOTONIC_PRECISE. It's an unportable synonym for
CLOCK_MONOTONIC.
* Use more appropriate names for some local variables.
* In the summary message, round elapsed time to the nearest microsecond.
Reported by: bde, jilles
MFC after: 3 days
X-MFC-With: 265472
conv=sparse.
This change fixes two separate issues observed when the last output
block is all zeroes, and conv=sparse is in use. In this case, care
must be taken to roll back the last seek and write the entire last zero
block at the original offset where it should have occurred: when the
destination file is a block device, it is not possible to roll back
by just one character as the write would then not be properly aligned.
Furthermore, the buffer used to write this last all-zeroes block
needs to be properly zeroed-out. This was not the case previously,
resulting in a junk data byte appearing instead of a zero in the
output stream.
PR: bin/189174
PR: bin/189284
Reviewed by: kib
MFC after: 2 weeks
gettimeofday returns the system clock, which may jump forward or back,
especially if NTP is in use. If the time jumps backwards, then dd will see
negative elapsed time, round it up to 1usec, and print an absurdly fast
transfer rate.
The solution is to use clock_gettime(2) with CLOCK_MONOTONIC_PRECISE as the
clock_id. That clock advances steadily, regardless of changes to the system
clock.
Reviewed by: delphij
MFC after: 3 days
Sponsored by: Spectra Logic
borrowed where syntax status=noxfer means no transfer statistics
and status=none means no status information at all.
This feature is useful because the statistics information can
sometimes be annoying, and redirecting stderr to /dev/null would
mean error messages also gets silenced.
Obtained from: OpenBSD
MFC after: 2 weeks
If the bs= expr operand is specified and no conversions other than sync,
noerror, or notrunc are requested, the data returned from each input
block shall be written as a separate output block.
In particular, when both bs=size and conv=sparce were specified, the
resulted file was fully filled, instead of sparce.
PR: standards/177742
Submitted by: Matthew Rezny <mrezny@hexaneinc.com>
MFC after: 2 weeks
Introduce an explicit close of the output descriptor so that work done
on close is accounted for in the summary output triggered at exit
(implicit close()s occur after atexit() hooks).
This is useful because some devices such as cfi(4) may perform
signficant work after a close occurs (e.g. erasing and rewriting a
block of flash).
This structure is not part of POSIX. According to POSIX, gettimeofday()
has the following prototype:
int gettimeofday(struct timeval *restrict tp, void *restrict tzp);
Also, POSIX states that gettimeofday() shall return 0 (as long as tzp is
not used). Remove dead error handling code. Also use NULL for a
nul-pointer instead of integer 0.
While there, change all pieces of code that only use tv_sec to use
time(3), as this provides less overhead.
to specify an alternative padding character when using a conversion
mode, or when using noerror with sync and an input error occurs. This
facilities reading old and error-prone media by allowing the user to
more effectively mark error blocks in the output stream.
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.
Approved by: arch@, new style(9)
what I was trying to do work much better (ie at all. I could have sworn
it was working...) Fix a SEEK_SET to be SEEK_CUR, and make Bruce's
lseek() test work correctly.
BDEification process of dd(1). Most of the changes are from BDE's archive.
Support for negative offsets is gone again, but the case where you
lseek() onto byte -1 of something from a negative offset using seek/skip
is fixed; if you end up on -1, you won't get a false positive lseek failure.
The biggest changes are to data types (more size_t, for instance) and
argument parsing. skip/seek on /dev/{,k}mem now occurs (instead of "read
until you reach the offset") due to mem devices now being D_DISK. Some
const things are now correctly declared as such, and the "case table"
building is better. The only thing that seems to be left to make dd(1)
everything TOG wants it to be is l10n.
request of Bruce. More changes may follow later. 'g' multiplier has
been added (i.e. dd seek=5g if=bigfile.) Some minor corrections were made
as well.
Noticed by: bde
statement if blocks[*] when the else could be ambiguous, not defaulting
to int type and removal of some unused variables.
[*] This is explicitly allowed by style(9) when the single statement
spans more than one line.
Reviewed by: obrien, chuckr
is also set.
Change osync to not to tack on an empty block if the input buffer is null,
or an even multiple of the blocksize.
Also change osync to pad the output with nulls/spaces depending whether
this is a block-oriented conversion or not (same as sync).
PR: 3818
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
and he's right ... I forgot about this floating point stuff you can
use in user-land :-)
Increase precision of duration to microseconds.
No heuristics to avoid overflow in calculation needed - just depend
on DBL_MAX being a bit larger than LONG_MAX.
Use double instead of `struct timeval' in dd.h so that everything
doesn't have to include <sys/time.h>.
Fixed style bugs in recent and old FreeBSD changes.
Reviewed by: phk
Submitted by: bde
