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class method
ENV.update
ENV.update → ENV
ENV.update(*hashes) → ENV
ENV.update(*hashes) { |name, env_val, hash_val| block } → ENV
ENV.merge! → ENV
ENV.merge!(*hashes) → ENV
ENV.merge!(*hashes) { |name, env_val, hash_val| block } → ENV
hash.c
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static VALUE
env_update(int argc, VALUE *argv, VALUE env)
{
rb_foreach_func *func = rb_block_given_p() ?
env_update_block_i : env_update_i;
for (int i = 0; i < argc; ++i) {
VALUE hash = argv[i];
if (env == hash) continue;
hash = to_hash(hash);
rb_hash_foreach(hash, func, 0);
}
return env;
}
Adds to ENV each key/value pair in the given hash; returns ENV:
Example
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('baz' => '2', 'bat' => '3') # => {"bar"=>"1", "bat"=>"3", "baz"=>"2", "foo"=>"0"}
Deletes the ENV entry for a hash value that is nil:
Example
ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}
For an already-existing name, if no block given, overwrites the ENV value:
Example
ENV.merge!('foo' => '4') # => {"bar"=>"1", "foo"=>"4"}
For an already-existing name, if block given, yields the name, its ENV value, and its hash value; the block’s return value becomes the new name:
Example
ENV.merge!('foo' => '5') { |name, env_val, hash_val | env_val + hash_val } # => {"bar"=>"1", "foo"=>"45"}
Raises an exception if a name or value is invalid (see Invalid Names and Values);
Example
ENV.replace('foo' => '0', 'bar' => '1') ENV.merge!('foo' => '6', :bar => '7', 'baz' => '9') # Raises TypeError (no implicit conversion of Symbol into String) ENV # => {"bar"=>"1", "foo"=>"6"} ENV.merge!('foo' => '7', 'bar' => 8, 'baz' => '9') # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "foo"=>"7"}
Raises an exception if the block returns an invalid name: (see Invalid Names and Values):
Example
ENV.merge!('bat' => '8', 'foo' => '9') { |name, env_val, hash_val | 10 } # Raises TypeError (no implicit conversion of Integer into String) ENV # => {"bar"=>"1", "bat"=>"8", "foo"=>"7"}
Note that for the exceptions above, hash pairs preceding an invalid name or value are processed normally; those following are ignored.