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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

Auxiliary script to rename multiple files adding a zero-padding to them

Posted 08-19-2014 at 12:37 AM by the dsc (linux-related notes)

From this blog:

http://www.walkingrandomly.com/?p=2850


Code:
#!/bin/bash
num=`expr match "$1" '[^0-9]*\([0-9]\+\).*'`
paddednum=`printf "%03d" $num`
echo ${1/$num/$paddednum}
Usage example:

for i in *.png;do mv $i `./zeropad.sh $i`; done


Possibly there's some syntax to do just that only with the "rename" command, though.
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Views 214 Comments 0 the dsc is offline
Old

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

Posted 08-08-2014 at 10:40 PM by the dsc (linux-related notes)
Updated 08-08-2014 at 10:42 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 172 Comments 2 the dsc is offline
Old

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

Posted 08-06-2014 at 10:36 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 198 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 08:11 PM by the dsc (linux-related notes)
Updated 08-03-2014 at 09:04 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 192 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 01:16 AM by the dsc (linux-related notes)
Updated 07-31-2014 at 01:39 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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Views 144 Comments 0 the dsc is offline

  



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