The use of array variable structures can be invaluable. This recipe describes several methods for declaring arrays in bash scripts.
The following are methods for declaring arrays:
names=( Jennifer Tonya Anna Sadie )
This creates an array called names with four elements (Jennifer, Tonya, Anna, and Sadie).
names=( "John Smith" "Jane Doe" )
This creates two array elements, each containing a space.
colors[0] = red
colors[3] = green
colors[4] = blue
This declares three elements of an array using nonsequential index values and creates a sparse array (there are no array elements for index values 1 or 2).
filearray=( `cat filename | tr '\n' ' '`)
This example places the contents of the file filename into an array. The tr command converts newlines to spaces so that multiline files will be handled properly.
names=( "${names[@]}" "Molly" )
This example adds another element to an existing array names.
If anyone has other techniques for creating or adding to arrays, add a comment to this recipe and share the wealth!
