affect a exploded a string into an array

Shell Programming and Scripting
1

I would like to affect an exploded string into an array.

one:two::four

into an array:

a[0] => one
a[1] => two
a[2] =>
a[3] => four

Quite simple in other languages with functions like explode() or split().

The best I could come up with was this:

until [ "$token" =  "$string" ]
do
        token=${string%%:*}    # takes the first token
        a[$i]=$token           # affects the token to the array element
        string=${string#*:}    # chops that token from the string
        ((i++))
done

This return what I was looking for but I find it quite heavy for something basic.

I also tried:

a=($(echo $string | nawk -F":" '{$1=$1; print}'))

But this skips the empty tokens as it returns

a[0] => one
a[1] => two
a[2] => four

Anything more simple for such a basic thing?

2 
#!/bin/ksh
Str=one:two::four
IFS=:
set -A Test $Str
let count=${#Test[@]}
let i=0
while [[ $i -lt $count ]]; do
print "Test[$i] ==> ${Test[$i]}"
((i=i+1))
done

Please check if this solves the problem,

Thanks
Nagarajan Ganesan

3

set -A arr `echo "one:two::four" | awk -F":" '{for(i=1;i<=NF;i++) print $i}'`
echo "${arr[0]}"
and so on.

4

@ennstate
Works fine in ksh but not in bash (I should have mentioned I was looking for a bash solution). Bash doesn't support the -A option for the set built in command. The only way I found to assign values to an array is array=(one two tree). And doing IFS=:; array=(one:two::four) doesn't work either.

@Deal_NoDeal
Also skips the empty fields as it returns
a[0] => one
a[1] => two
a[2] => four

instead of

a[0] => one
a[1] => two
a[2] =>
a[3] => four

Still trying.

5

In bash or ksh93:

string=one:two::four
oldIFS=$IFS
IFS=:
a=( $string )
IFS=$oldIFS

In any POSIX shell:

string=one:two::four
unset a
while :
do
  case $string in
     *:*) a[${#a[@]}]=${string%%:*}
             string=${string#*:}
             ;;
     *) a[${#a[@]}]=${string%%:*}
         break ;;
  esac
done
6

Works fine.

I did try changing the value of IFS but not correctly. Strange that you can assign values by doing:

a=(one two three)

But the following does not work

IFS=:
a=(one:two:three)

You have to first put the string in a variable as you did. Thank you.

7

If you are writing the literal values, there's no reason to use a colon:

a=( one two three )
8

hello every one,
I want to convert an array into list
for example the file is "agt
aag"
I need to conert it into
a
g
t
a
a
g
how I can do that in Perl?
please I need help

9

bioinf,

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Proceed here: I need help please

Thank You.

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