Also, I only now realized that only mknod existed, up until a long time, only later on with the GNU coreutils did mkdir as a command come into existence. Running the PDP-11 v7 on SIMH showed that, gotten so accustomed to the Linux env that thinking backwards seemed suddenly arcane. On Mon, Oct 21, 2019 at 4:13 PM Abhinav Rajagopalan < abhinavrajagopalan(a)gmail.com&gt; wrote: -- Abhinav Rajagopalan

Thanks, didn't mean it as a GNU thing at all. Sure, mkdir would've existed back in research Unix too. My experience has only been limited to the Linux envs, which is why I was led to attribute mkdir to the evolution in mknod(), I only know that they all either descended down from SysV or BSD, those who have used the real Unices would know better. Seeing as I haven't had the privilege of using any except briefly on an emulator. On Mon, Oct 21, 2019 at 5:30 PM Thomas Paulsen &lt;thomas.paulsen(a)firemail.de&gt; wrote: -- Abhinav Rajagopalan

dd is deprecated?  I'm surprised. I use it all the time. It's great when a blocksize of 512 is too slow, like for large files onto slow backup disks or network transfers, I might use dd bs=10240 or some such thing. I suppose the block size on Linux might be bigger these days, but the command is still standard.     Mary Ann On 10/22/19 11:07 AM, Peter Jeremy wrote:

On Tue, Oct 22, 2019 at 07:02:03PM -0700, Kurt H Maier wrote: I really need to move this into the distros, it's dd on steriods and the docs don't list the latest options, I made it go backwards, I made it use the crc/xor stuff that bk has, I made it use the compression stuff that bk has: LMDD(8) LMBENCH LMDD(8) NAME lmdd - move io for performance and debugging tests SYNOPSIS lmdd [ option=value ] ... DESCRIPTION lmdd copies a specified input file to a specified output with possible conversions. This program is primarily useful for timing I/O since it prints out the timing statistics after completing. OPTIONS if=name Input file is taken from name; internal is the default. internal is a special file that acts like Sun's /dev/zero, i.e., it provides a buffer of zeros without doing a system call to get them. The following file names are taken to mean the standard input: -, 0, or stdin. of=name Output file is taken from name; internal is the default. internal is a special file that acts like /dev/null, without doing a system call to get rid of the data. The following file names are taken to mean the standard output: -, 1, or stdout. The following file names are taken to mean the standard error: 2, or stderr. bs=n Input and output block size n bytes (default 8192). Note that this is different from dd(1), it has a 512 byte default. Also note that the block size can be followed by 'k' or 'm' to indicate kilo bytes (*1024) or megabytes (*1024*1024), respectively. ipat=n If n is non zero, expect a known pattern in the file (see opat). Mismatches will be displayed as "ERROR: off=%d want=%x got=%x". The pattern is a sequence of 4 byte integers with the first 0, second 1, and so on. The default is not to check for the pattern. opat=n If n is non zero, generate a known pattern on the output stream. Used for debugging file system correctness. The default is not to generate the pattern. mismatch=n If n is non zero, stop at the first mismatched value. Used with ipat. skip=n Skip n input blocks before starting copy. fsync=n If n is non-zero, call fsync(2) on the output file before exiting or printing timing statistics. sync=n If n is non-zero, call sync(2) before exiting or print- ing timing statistics. rand=n This argument, by default off, turns on random behavior. The argument is not a flag, it is a size, that size is used as the upper bound for the seeks. Also note that the block size can be followed by 'k' or 'm' to indicate kilo bytes (*1024) or megabytes (*1024*1024), flush=n If n is non-zero and mmap(2) is available, call msync(2) to invalidate the output file. This flushes the file to disk so that you don't have unmount/mount. It is not as good as mount/unmount because it just flushes file pages - it misses the indirect blocks which are still cached. Not supported on all systems, compile time option. rusage=n If n is non-zero, print rusage statistics as well as timing statistics. Not supported on all systems, com- pile time option. count=n Copy only n input records. EXAMPLES This is the most common usage, the intent is to measure disk perfor- mance. The disk is a spare partition mounted on /spare. # mount /spare # lmdd if=internal of=/spare/XXX count=1000 fsync=1 7.81 MB in 3.78 seconds (2.0676 MB/sec) : Flush cache # umount /spare # mount /spare # lmdd if=/spare/XXX of=internal 7.81 MB in 2.83 seconds (2.7611 MB/sec) AUTHOR Larry McVoy, lm(a)sun.com (c)1994 Larry McVoy $Date$ LMDD(8)

On Wed, Oct 23, 2019 at 3:04 AM Thomas Paulsen &lt;thomas.paulsen(a)firemail.de&gt; wrote: dd isn't deprecated. There's no heir apparent, it's in POSIX.1 and there's no advantage to changing. There's not even been talk of that, at east in *BSD land. Warner

On 23 Oct 2019 21:23 -0500, from mparson(a)bl.org (Michael Parson): The only thing resembling "deprecation" of dd that I'm aware of is the recommendation I saw many years ago to not use it to copy potentially problematic storage media (for data recovery), but to use ddrescue for that purpose instead. The reason for this is that with conv=noerror (without which it'd simply abort if it encounters an I/O error), dd would simply skip past data in the input that it can't read, but not adjust any offsets in the output, which wreaks havoc with anything where offsets matter (such as in file system metadata). That wouldn't surprise me in the slightest. -- Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se “The most dangerous thought that you can have as a creative person is to think you know what you’re doing.” (Bret Victor)

On Fri, 25 Oct 2019, Arthur Krewat wrote: Looks like dd was introduced in Fifth Edition (and had those conversion values).

On Mon, 21 Oct 2019 at 06:45, Abhinav Rajagopalan < abhinavrajagopalan(a)gmail.com&gt; wrote: I am pretty sure that "dd" derives from the "DD" statement in IBM JCL that stands for "Data Definition" Here's a link to practical-ish documentation about that: https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zjcl/zjcl… On MVS, TSO, and such systems, compiled programs would be written in languages like COBOL, PL/1, FORTRAN, and such, and the programs would commonly reference input and output devices. The programs are controlled (we could say, "scripted") by JCL code that indicate the files (possibly other devices) to be connected up. Each file that is accessed gets its own DD line in the JCL script that indicates the various metadata about the file, such as its name, block size, storage class, how much space is allocated, literally dozens of options. Back in the '90s my "Y2K remediation" involvement was at American Airlines; I was one of the Unix guys working alongside mainframe guys; as soon as I started seeing the JCL for their TSO batch jobs, it was pretty obvious that this was from whence derived the dd command on Unix. The mainframe guys enthused a lot about a sorting tool with similar syntax called SyncSort that they'd use to do many of the things we'd do with cut and grep. The Jargon File claim that dd is deprecated makes little sense; dd is THE good tool for grabbing exact chunks of data out of binary files, and I haven't seen a would-be successor. It would be interesting to see some alternative constructed; given that it's all about dealing with pretty messy sorts of I/O work, an alternative is liable to have its messiness in different places. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?"