README.md

shell_map

A full featured Map implementation in bash script, providing de functionality of a HashMap. Developed using bash 3.

See the file test_shell_map.sh for more usage examples.

If you want to understand how shell_map is implemented, take a look at IMPLEMENTATION_NOTES.md

# Usage

# importing shell_map.sh
source shell_map.sh

# instantiating a new shell_map with the name 'users'
shell_map new users

# storing key value pairs
users put jdavis "John Davis"
users put bnegrao "Bruno Negrao" 
users put msilva "Mariana Silva"

# retrieving values from the map 
users get jdavis      # returns "John Davis"

# test if a key exists
users contains_key msilva && echo "msilva's name is `users get msilva`" 

# iterating through all keys in 'users' shell_map 
for username in `users keys`; do
	name=`users get $username`
	echo "user $username, name: $name"
done

Constructor

• new <mymap>: instantiates a new shell_map instance named <mymap>

Methods

• clear_all: remove all the key value pairs from the map
• contains_key <key>: returns true if the <key> exists in the map, returns false otherwise.
• get <key>: retrieves the value associated with <key>
• keys: retrieves a list of key names, separated by new line characters.
• put <key> <value>: stores <value> associated with <key>. valid key name must be a string consisting solely of letters, numbers, and underscores.
• put_append <key> <value>: convenience method that appends <value> to an existing key value. Creates a new key if it didn't exist.
• put_increment <key> <value>: convenience method that stores a numeric <value> incrementing the existing value.
• remove <key>: removes a key from the map.
• size: return the number of keys contained in the map