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Getting Absolute Paths of UNIX Directories and Filenames in Shell Scripts

Posted 07-08-2011 at 03:05 AM by konsolebox
Updated 05-27-2018 at 03:20 PM by konsolebox

This post is a compilation of the function getabspath() for different shells that can be used to get the absolute form of a path. The function accepts an argument path then returns the absolute form of it to the variable $__.

Bash

Code:

function getabspath {
	local t=() i=0 IFS=/

	case $1 in
	/*)
		__=${1#/}
		;;
	*)
		__=${PWD#/}/$1
		;;
	esac

	case $- in
	*f*)
		set -- $__

...

konsolebox

Senior Member

Posted in Howtos

Views 4304 Comments 0 konsolebox is offline

If condition "if condition ... if condition"

Posted 08-28-2010 at 06:26 PM by the dsc (linux-related notes)
Updated 06-01-2023 at 12:47 PM by the dsc

Tags bash, check, conditions

If you want to have a script that would do something if either one of two consequences is true, a simple way to do that would be:

Code:

if [ condition 1 ] || [ condition 2 ] ; then
if [ condition 1 ] ; then
consequences for condition 1
fi
if [ condition 2 ] ; then
consequences for condition 2
fi
consequences of either one, but happens only once, not twice
fi
...

You check if either one is true, when "||"...

the dsc

Member

Posted in Uncategorized

Views 1556 Comments 0 the dsc is offline

Shortest command to calculate the sum of a column of output

Posted 06-02-2010 at 06:27 AM by bittner (Notes on Linux)

Tags bash, debian, packaging, script

I had to calculate the Installed-Size for a .deb control file recently. Here is the solution I came up with:

Code:

dpkg-deb -c mypackage.deb | sed -e 's/.*root\s*//' -e 's/\s*2010-.*$//' | xargs | tr ' ' + | bc

What it does? The code tries to construct a calculation string and feeds it to the command line calculator bc as follows:

use dpkg-deb to get the file size information out of the Debian package
sed away all characters before and after the

...

bittner

LQ Newbie

Posted in Uncategorized

Views 7970 Comments 2 bittner is offline

having fun with bash varaibles: indirect variable references

Posted 11-28-2009 at 01:38 PM by lumak (Lumak's Guide to Random Things)
Updated 11-28-2009 at 02:59 PM by lumak

Tags bash, indirect, variable

Well I recently started messing around with bash scripts as cgi scripts and was wondering how to pass variables in and what not.

Well it turns out, Apache will define the variable $QUERY_STRING which will contain everything after the first question mark. You can then pars this string to define variables. The general format is "name1=val1&name2=val2". It turns out you can actually declare variables in bash using 'declare' and parameter expansion.

...

Attached Files

cgi_vars.txt (2.4 KB, 529 views)

lumak

Member

Posted in Random Bash Scripts

Views 15019 Comments 2 lumak is offline

If - how to use

Posted 12-05-2008 at 02:27 AM by kshfi (Jukka's script corner)
Updated 12-07-2008 at 09:57 AM by kshfi

Tags bash, ksh

Programmers - shell if is command.

Code:

if command exit code is 0
then
    do something 1
    do something 2
fi

Ex.

Code:

if  cp fromfile tofile
then
   echo "Works fine"
else
   echo "Error ???"
fi

[ = test
You can write test or [

Code:

a=1
b=1
test "$a" = "$b"
echo $?
0

a=1
b=2

...

kshfi

LQ Newbie

Posted in Sh handbook, syntax, FAQ

Views 1904 Comments 0 kshfi is offline

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