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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for March 13th, 2020

worksheet function – How to add or subtract to, or increment, column letters in Excel? – Super User

Posted by jpluimers on 2020/03/13

[WayBack] worksheet function – How to add or subtract to, or increment, column letters in Excel? – Super User:

Here’s the best I’ve found so far: =SUBSTITUTE(ADDRESS(1,( COLUMN() + 1 ),4),1,"")The part in the middle marked in bold is the only part that changes. In this example, it’s taking the current column and adding 1, so returning B if it’s in column A and AA if it’s in column Z.

It is related to the question and answer [WayBack] Formula to return just the Column Letter in excel – Super User:

FYI on your original formula you don’t actually need to call the CELL formula to get row and column you can use:

=ADDRESS(ROW(),COLUMN())

Then as an extension of that you can use MID & SEARCH to find the $ and trim down the output so you are just left with the letter:

=MID(ADDRESS(ROW(),COLUMN()),SEARCH("$",ADDRESS(ROW(),COLUMN()))+1,SEARCH("$",ADDRESS(ROW(),COLUMN()),SEARCH("$",ADDRESS(ROW(),COLUMN()))+1)-2)

edit You can even simplify this further:

=MID(ADDRESS(ROW(),COLUMN()),2,SEARCH("$",ADDRESS(ROW(),COLUMN()),2)-2)

And it is part of a much more elaborate answer

Read the rest of this entry »

Posted in Development, Excel, Office, Power User, Software Development | Leave a Comment »

MacOS: Checking a disk for bad blocks

Posted by jpluimers on 2020/03/13

Hardware fails, but most disk tools on MacOS only check logical disk structures, not bad blocks.

Luckily, fsck_hfs can, though Apple is a bit secretive on it: [WayBack] Page Not Found – Apple Developer: ManPages/man8/fsck_hfs.8.html is empty, but there is [WayBack] man page fsck_hfs section 8 and the gist below.

Disk volumes on MacOS use a successor of HFS called HFS Plus – Wikipedia, but the tooling never changed names.

I got at the below parameters through [

This is the disk check command:

# sudo fsck_hfs -dylS /dev/disk3s1
** /dev/rdisk3s1 (NO WRITE)
    Using cacheBlockSize=32K cacheTotalBlock=65536 cacheSize=2097152K.
Scanning entire disk for bad blocks
   Executing fsck_hfs (version hfs-407.50.6).
** Performing live verification.
** Checking Journaled HFS Plus volume.
   The volume name is SanDisk400GB
** Checking extents overflow file.
** Checking catalog file.
** Checking extended attributes file.
** Checking volume bitmap.
** Checking volume information.
** The volume SanDisk400GB appears to be OK.
    CheckHFS returned 0, fsmodified = 0

The italic part is the bad block scanning. The normal part the hfs scanning, which will continue even after finding bad blocks.

If bad blocks are found, output looks more like on the right. If it looks like that, basically you know a disk is toast.

It can be slow, as I did not specify a cache, so it defaults to 32 Kibibyte. You can increase that by adding for instance -c 512m  for 512 Mebibyte cache, just read the short help or man page below.

This tremendously helps checking volumes containing many files, for instance [WayBack] Checking Very Large Time Machine Volumes – Mac OS X Hints

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Posted in Apple, Mac, Mac OS X / OS X / MacOS, Power User | Leave a Comment »

Some links on bind rndc

Posted by jpluimers on 2020/03/13

No, this is not a random number generator, according to the documentation, bind rndc is the name server control utility. Again very undescriptive; luckily the full name found elsewhere is Remote Name Daemon Control.

Some links for my archive as often there are no man-pages installed on systems with bind:

–jeroen

Posted in *nix, bind-named, Linux, Power User | Leave a Comment »

Show the mmc and USB disks on a Raspberry Pi

Posted by jpluimers on 2020/03/13

Small trick:

find /dev | grep "sd\|mmc" && ls -al /dev/disk/by-id/

–jeroen

Posted in *nix, *nix-tools, Power User | Leave a Comment »

 
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