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Just annotations of little "how to's", so I know I can find how to do something I've already done when I need to do it again, in case I don't remember anymore, which is not unlikely. Hopefully they can be useful to others, but I can't guarantee that it will work, or that it won't even make things worse.
Old

[bash] "keep trying" command, even if exits with error, for at least 10 times

Posted 08-08-2014 at 11:40 PM by the dsc (linux-related notes)
Updated 08-08-2014 at 11:42 PM by the dsc
Tags bash

A script that tries to run a given arbitrary command N times, or until it exits with success. The commented parts are aborted attempts to make it figure whether the first parameter is a number instead of a command, and that would be used as the maximum number of attempts. Something went wrong, sometime I'll try to figure it out.

Quote:
#!/bin/bash
#input="$@"
# this program is stupid. It's declared to be in public domain by its author, who whishes to remain anonymous
...
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Posted in Uncategorized
Views 215 Comments 2 the dsc is offline
Old

Note to myself, for whenever I get an SSD...

Posted 08-06-2014 at 11:36 PM by the dsc (linux-related notes)
Tags ssd, swap

If it would still apply for future technology...

Quote:
Current good quality SSDs have built-in mechanisms to level the wear on the whole device so that their lives are maximised, but for something like Swap the inherent nature of that requirement will significantly ratchet up the number of Write cycles on any drive that hosts it, and that is still something I want to avoid on my SSD.

In reality it may not be a factor, but I'd rather spend a few dollars on more RAM to reduce
...
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Posted in Uncategorized
Views 253 Comments 0 the dsc is offline
Old

Listing the average file size for all subfolders (+listing subfolders without ls or find)

Posted 08-03-2014 at 09:11 PM by the dsc (linux-related notes)
Updated 08-03-2014 at 10:04 PM by the dsc

A tiny "Frankenstein monster" one liner, adding a little bit from several sources/blogs/blog comments:

lsf | while read d ; do find ./"$d" -iname "*.*" -type f -printf "%k\n" | gawk '{sum += $1; n++;} END {print sum/n;}' |sed "s|$| -- $d|" ; done | sort -n

Where the first "command", "lsf" is actually a custom function:

Code:
lsf ()
{
for f in * ; do [ -d "$f" ] &&
...
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Posted in Uncategorized
Views 242 Comments 0 the dsc is offline
Old

Bash quickie] Get a "random" number (larger than zero, within a range) with "shuf" only

Posted 07-31-2014 at 02:16 AM by the dsc (linux-related notes)
Updated 07-31-2014 at 02:39 AM by the dsc (deweirdifying the wording)

It always annoys me when I see things like "cat file | grep pattern | sed ..." when just "sed" would suffice, but I was guilty of using seq only to shuf random numbers when shuf can do it by itself.

shuf -n 1 -i 0-999999999

(apparently the largest number you can get is $((9999**8)) (9999^8 in bash-math), larger than that it gets negative, for some reason )


You also don't need to do some fancy "echo -e" with several...
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Posted in Uncategorized
Views 182 Comments 0 the dsc is offline
Old

KDE's "ark" as a command-line universal (un)archiver

Posted 07-28-2014 at 03:44 PM by the dsc (linux-related notes)
Tags ark, zip

For some reason I was having issues with some zip files. "Unzip" wouldn't unzip them, but ark (and perhaps other GUI archivers) would.

Fortunately ark can be used as a command line tool as well, which can be better than needlessly opening the full GUI just to make something so trivial. You still can invoke just the dialog, anyway.

But in order to extract something, for example, one can just use:

ark -b file.zip -o ./extantfolder

...
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Posted in Uncategorized
Views 190 Comments 0 the dsc is offline

  



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