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up vote 3 down vote favorite

I need to remove an element from an array in bash shell. Generally I'd simply do:

array=("${(@)array:#<element to remove>}")

Unfortunately the element I want to remove is a variable so I can't use the previous command. Down here an example:

array+=(pluto)
array+=(pippo)
delete=(pluto)
array( ${array[@]/$delete} ) -> but clearly doens't work because of {}

Any idea?

Thanks!

share|improve this question
    
Which shell? Your example looks like zsh. –  chepner May 31 '13 at 16:30

3 Answers 3

up vote 7 down vote accepted

The following works as you would like in bash and zsh:

$ array=(pluto pippo)
$ delete=(pluto)
$ echo ${array[@]/$delete}
pippo
$ array=( "${array[@]/$delete}" )
share|improve this answer
    
Thanks, it's perfect. –  Alex May 31 '13 at 17:00
1  
just know that: $ array=(sun sunflower) $ delete=(sun) $ echo ${array[@]/$delete} results in flower –  bernstein Mar 26 at 14:41
1  
Good point. At least in zsh, ${array[@]/#%$delete} works to restrict the match to full words. –  chepner Mar 26 at 14:49
    
Doesn't work if delete=(pluto pippo) –  tommy.carstensen Jun 24 at 18:11
up vote 0 down vote

POSIX shell script does not have arrays.

So most probably you are using a specific dialect such as bash, korn shells or zsh.

Therefore, your question as of now cannot be answered.

Maybe this works for you:

unset array[$delete]
share|improve this answer
    
Hi, I'm using bash shell atm. And "$delete" is not the position of the element but the string itself. So I don't think "unset" will work –  Alex May 31 '13 at 16:07
up vote 0 down vote

You could set the element you want to destroy to an empty string, it will be considered as deleted.

The following example show you how to delete the b string in a a b c d array:

$ array=(a b c d)
$ echo ${array[@]}
a b c d
$ for i in ${!array[@]} ; do # iterate over array indexes
    if [ ${array[$i]} = 'b' ] ; then # if it's the value you want to delete
      array[$i]='' # set the string as empty at this specific index
    fi
  done
$ echo ${array[@]}
a c d

Note this solution works even in a POSIX shell like sh.

share|improve this answer
    
But unfortunately I don't know what's the position of the element that I want to destroy. –  Alex May 31 '13 at 16:00
    
I edited my answer. –  aymericbeaumet May 31 '13 at 16:15
    
Great, just instead of array[i]='' put it as array[$i]='' –  user2431227 May 30 at 9:06
    
Thanks for pointing the typo. –  aymericbeaumet Jun 1 at 16:44

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