Is there a better way? (BASH Script)

Tadaen · 02-06-2014, 04:51 PM

I am writing up an installer script for myself. I am aiming this thing at Ubuntu / Mint at the moment but would like it to be easily portable with straight Debian or quickly modified to work with something non Debian based. I am trying to get it to test the distro. If it is ubuntu or mint then it runs the ppa function. if not then it just moves on down the list in the while loop running the functions.

Code:

testdistro()
{
	if cat /proc/version | grep [U,u]buntu ; then
		addppa
	elif cat /proc/version | grep [M,m]int ; then
		addppa
	fi
}
		
addppa() ###Called from testdistro###
{
	if [ ! -s $SOURCES.d/satyajit-happy* ] ; then
		add-apt-repository ppa:satyajit-happy/themes
	fi
}

Is there a better way of doing this? Smaller and more compact maybe?

Tadaen · 02-06-2014, 06:36 PM

Found my answer using grep. If anyone needs...

Code:

if cat /proc/version | grep -iw 'word1\|word2' ; then

Whole function for posterity

Code:

addppa()
{
	if cat /proc/version | grep -iw 'mint\|ubuntu' >/dev/null ; then 
		if ! ls $SOURCES.d/satyajit-happy* >/dev/null ; then
			add-apt-repository ppa:satyajit-happy/themes
		fi
	fi
}

Firerat · 02-06-2014, 07:54 PM

This is how I would do it

Code:

#!/bin/bash
unset PPA
PPA+=("satyajit-happy/themes")
PPA+=("anotherPPA/Main")
PPA+=("yappa/other")
# http://www.tldp.org/LDP/Bash-Beginners-Guide/html/sect_10_02.html # bash array intro
# http://mywiki.wooledge.org/BashGuide/Arrays
 
SOURCES="/etc/apt/sources.list.d"
 
# http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-8.html
# 8.2 Functions with parameters
addppa() {
[[ -e "${SOURCES}/${1%/*}.list" ]] || echo add-apt-repository ppa:${1}
# http://tldp.org/LDP/abs/html/string-manipulation.html
# http://tldp.org/LDP/abs/html/list-cons.html
}
 
grep -qiw 'mint\|ubuntu' /proc/version && (
    for (( i=0;i<${#PPA[@]};i++));do
        addppa ${PPA[$i]}
    done
# http://tldp.org/LDP/abs/html/loops1.html # c style loop
# since arrays start at 0 it is easier to use that style
) || (
    echo "not mint or ubuntu"
    # extra stuff here
)
 
exit

note the list construct with the grep, && ( do when true) || (do when false )

PS
don't forget useless use of cat

https://startpage.com/do/search?q=useless+use+of+cat

Tadaen · 02-08-2014, 12:14 AM

Quote:

don't forget useless use of cat

https://startpage.com/do/search?q=useless+use+of+cat

Is this what suggesting? This...

Code:

if grep -iw 'word1\|word2' < /proc/version ; then

instead of

Code:

if cat /proc/version | grep -iw 'word1\|word2' ; then

Just to make sure I understand what the link sent me to.