* 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).
In addition to adding missing `static' keywords:
- bin/dd: Pull in `extern.h' to guarantee consistency with source file.
- libexec/rpc.rusersd: Move shared globals into an extern.h.
- libexec/talkd: Move `debug' and `hostname' into extern.h.
- usr.bin/cksum: Put counters in extern.h, as they are used by ckdist/mtree.
- usr.bin/m4: Move `end_result' into extern.h.
- usr.sbin/services_mkdb: Move shared globals into an extern.h.
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.
This should be a bit useful for users who look at the manpage and
then try to copy data CD-ROM disks using dd. A lot of us know
that bs=2048 is required, but it still manages to cause a bit of
grief to those who haven't heard about it.
PR: bin/130857
Submitted by: Tri Brotoharsono < mail at tribrotoharsono.net >
MFC after: 3 days
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.
Revert to using the .Tn POSIX and .Tn ANSI instead of \*[Px] and \*[Ai]
strings; using these strings is unsafe in troff mode, as they include a
change in a font size.
Approved by: re
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)
signal. Fix it by adding an explicit call to summary() in terminate()
(it was previously called implicitly by exit() because summary() was
registered with atexit()). summary() is supposed to be signal-safe--
it handles SIGINFO almost exclusively--so this should be safe.
Submitted by: bde
operands. Can _YOU_ tell skip= and seek= apart with 100% accuracy
every time?
This also seems to make us option-for-option compatible with the
Solaris dd(1).
Approved by: jkh
Suggested by: peter
bfumerola for that pointer!) in GCC complaining about losing a const.
While I'm here, might as well mark in the Makefile that I'm the
${MAINTAINER}. It seems like that's what everyone's doing these days.
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.
useful as a seeking-tool as well as its many other uses. Previously,
dd(1) would succeed with count=0, but wouldn't get to the point that
blocks were to be read/written. This is a more useful behavior, and
this specific case doesn't seem to be handled by POSIX.
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
specifies exiting with a zero status if the file was copied
successfully, and with a nonzero status if an error occurred. We
are too sloppy to tell if the file was copied successfully when we
get killed by a SIGINT, but it is unlikely to have been. Added a
comment about related sloppiness (calling exit() from a signal
handler).
