bash: arrays
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Associative arrays:
# Local:
declare -A my_array
# Global:
declare -gA my_array
declare -A my_array=( ['']='empty' [0]='zero' ['a']='letter' )
# Add item to the array
my_array+=('banana'='fruit')
# Iterate over array:
for i in "${my_array[@]}"
do
echo $i
done
Array indirection
Use a temporary variable to allow for array addressing indirection.
# $1 = 'my_array
declare -gA $1 # Declare array
# $1+=('banana'='fruit') # Will not work!
var=$1
var+=('banana'='fruit') # Ok. Adds an element to the array.
Also, consider this:
#!/bin/bash
function array_add {
eval `echo "$1['$2']='$3'"`
}
declare -A my_map
my_map['first']='a'
my_map['second']='b'
my_array='my_map'
array_add $my_array 'third' 'c'
for key in ${!my_map[@]}; do
echo -e "[$key]\t ${my_map[$key]}"
done
Iterate over an array
#!/bin/bash
for element in "${my_array[@]}"
do
echo "${element}"
done
To access the keys instead of the elements, add an exclamation mark:
#!/bin/bash
for key in "${!my_array[@]}"
do
echo "${my_array[$key]}"
done
See also:
Issues related to this page:
Project | Summary | Status | Priority | Category | Last updated | Assigned to |
---|---|---|---|---|---|---|
Programming | Bash: iterate over bash array in the order the … | active | normal | support request | 8 years 47 weeks |