Bash Script Array index value

Kedelfor · 05-21-2005, 10:21 AM

Is there any way to get the value that is in the array index. ie

array[1]=one
array[2]=two
array[3]=three

That would be an array and I want the index values to be printed as well not just the value of the array.

Thanks

keefaz · 05-21-2005, 10:43 AM

Something like :

Code:

#!/bin/bash

array=(one two three)
count=${#array[@]}
index=0
while [ "$index" -lt "$count" ]; do
    echo -e "index: $index\tvalue: ${array[$index]}"
    let "index++"
done

See :
http://linuxreviews.org/beginner/Bas.../en/x4945.html
http://www.die.net/doc/linux/abs-guide/arrays.html

Kedelfor · 05-21-2005, 11:56 AM

Well what I forgot to mention was that I am using a wierd scheme for my index numbers. They are kind of like reference numbers, hence why i would want to know what they are so I can use what the refernce to in my scripts.

keefaz · 05-21-2005, 12:42 PM

I think you will get better result with searching the index in the array
from a value reference like :

Code:

#!/bin/bash

function search_array() {
    index=0
    while [ "$index" -lt "${#myArray[@]}" ]; do
        if [ "${myArray[$index]}" = "$1" ]; then
            echo $index
            return
        fi
        let "index++"
    done
    echo ""
}

myArray=(one two three)
value="one"

index=$(search_array $value)

if [ -z "$index" ]; then
    echo -e "the value \"$value\" is not in \$myArray"
else
    echo -e "the value \"$value\" was found at index: $index"
fi

Kedelfor · 05-21-2005, 12:55 PM

All I really want to do is know if i can print the number. I will show you what i mean

I have a number sequence like

server[101]=Server 1
server[201]=Server 1
server[301]=Server 1
server[401]=Server 1
server[501]=Server 1

Not in numeric order

they would reference somehting like

101=Site1
201=site2
etc...

I was wondering if i could just echo the index number so i can reference to it like if ${server[ID]} so i can say like

Server 1 at Site1

Does this make sense at all???

keefaz · 05-21-2005, 01:05 PM

Well you could echo just the index number with my function above,
just replace 'myArray' with 'server', although it won't work wiith
arrays that contains multiple same values...

Now if there are some built-in or shorter functions to echo the index
of a bash array, I will like to see it

Kedelfor · 05-21-2005, 01:35 PM

Thank you for all your input, I know witch some other languages you can just output the index name. i wasn't sure if bash had that or not. Thanks again for your help.

mphadnis · 10-20-2008, 03:39 PM

Kedelfor,

were you able to find a solution to your question? I need to do the exact same thing, TIA

atelszewski · 11-11-2008, 08:39 AM

Hello,

I found this construct to solve your problem: ${!array[*]}

Code:

#!/bin/sh

array[5]="tom"
array[13]="jenny"
array[77]="julie"

echo ${!array[*]} # find all the indexes

# print all indexes and associated values
for I in ${!array[*]}; do
  echo $I: ${array[$I]}
done

Best regards,
atelszewski

pooryorick · 04-18-2009, 10:30 PM

note that the syntax used by atelszewski did not exist in earlier versions of bash.

--
Poor Yorick
www.pooryorick.com

14341 · 04-29-2009, 04:37 AM

i think one needs to enable the extended pattern matching using

Code:

shopt -s extglob

for the above specified code to work.