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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 variables storing the output of commands run them at each variable statement, not just at some eventual invocation

Posted 08-10-2016 at 04:30 PM by the dsc (linux-related notes)
Updated 08-10-2016 at 04:33 PM by the dsc
Tags bash

Meaning that a script line such as:

nowstatus=`mpc | grep '#' | cut -d '/' -f1`

Is running mpc, grep and cut at its very statement, not only from an eventual "echo $nowstatus".

Therefore, in scripts that parse differently the same output of a given command, it may be preferable to first store this output in a temporary file, and then parse this file rather than running the same command several times. Such as in the lines added below their equivalent...
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Posted in Uncategorized
Views 154 Comments 0 the dsc is offline
Old

N00b method to toggle some verbosity on command for bash scripts

Posted 03-28-2016 at 11:32 PM by the dsc (linux-related notes)
Updated 03-28-2016 at 11:34 PM by the dsc
Tags bash, newbie

Just something I came up with that is probably not how actual programmers/scripters(?) would advise, specially the parameter/flag thing which is beside the point here.

Code:
if [[ $1 == "v" ]] ; then

ver(){
echo $@
}

else

ver(){
:    # ":" is a "do nothing" command
}

fi

a=10

echo normal output

ver verbose output $a
...
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Posted in Uncategorized
Views 181 Comments 0 the dsc is offline
Old

New file name generator script/function, to avoid overwrites w/o user input

Posted 03-27-2016 at 07:11 PM by the dsc (linux-related notes)

Usage examples:

cp/mv/ln/etc file11.txt $(newname "/some/path/file11.txt")

cp/mv/ln/etc file11.txt $(newname "/some/path/whatever.txt")


If there's a file11.txt or whatever.txt already there, it will rename automatically to file11(1).txt or whatever(1).txt, and (N+1) from then on.

The whole path/name must be between quotes because of spaces and such things.

May be dangerous and somehow make you lose files...
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Posted in Uncategorized
Views 193 Comments 0 the dsc is offline
Old

Parsing script arguments in bash, without getopt(s)

Posted 03-12-2016 at 05:15 PM by the dsc (linux-related notes)
Tags arguments, bash

Nifty. Just found that on stackoverflow:

http://stackoverflow.com/questions/1...uments-in-bash

Quote:
Originally Posted by Bruno Bronosky, cwd, et al.
Preferred Method: Using straight bash without getopt[s]

I originally answered the question as the OP asked. This Q/A is getting a lot of attention, so I should also offer the non-magic way to do this. I'm going to expand upon guneysus's answer to fix the nasty sed and include Tobias Kienzler's suggestion.

Two
...
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Posted in Uncategorized
Views 523 Comments 2 the dsc is offline
Old

Make a bash script recognize bash aliases

Posted 05-12-2015 at 04:16 PM by the dsc (linux-related notes)
Updated 05-12-2015 at 04:22 PM by the dsc (mismatched tags)

Say, if you have a script that would take as a parameter something that you have aliased, it wouldn't work.

I mean:

$ ./script.sh myalias whatever else
/home/dude/scripts/script.sh: line 3: myalias: command not found



In order to make it work, the said script must include:

Code:
shopt -s expand_aliases
source ~/.bash_aliases
(Or wherever your aliases are set, which would preferably be...
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Posted in Uncategorized
Views 538 Comments 0 the dsc is offline

  



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