Question

How To Use Array In Shell Script?

Answer 1

Only noteworthy in this program is the syntax for the usage of arrays.

Code:

echo "ENTER THE NO. OF ARRAY ELEMENTS"
read n
i=1
while [ $i -le n ]
 do 
   read a[$i]
   let i = $i + 1
 done

i=1
while [ $i -le n ]
 do 
   echo ${a[i]}
   let i = $i + 1
 done

 

Comments

How can we declare and create new arrays in bash?

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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:

Code:

names=( Jennifer Tonya Anna Sadie )

This creates an array called names with four elements (Jennifer, Tonya, Anna, and Sadie).

Code:

names=( "John Smith" "Jane Doe" )

This creates two array elements, each containing a space.

Code:

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).

Code:

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.

Code:

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!