ENV

ENV[name] → value

::

          
            static VALUE
rb_f_getenv(VALUE obj, VALUE name)
{
    const char *nam, *env;

    nam = env_name(name);
    env = getenv(nam);
    if (env) {
        return env_name_new(nam, env);
    }
    return Qnil;
}

Returns the value for the environment variable name if it exists:

ENV['foo'] = '0'
ENV['foo'] # => "0"

Returns nil if the named variable does not exist.

Raises an exception if name is invalid. See Invalid Names and Values.

ENV.store(name, value) → value

::

hash.c View on GitHub

          
            static VALUE
env_aset_m(VALUE obj, VALUE nm, VALUE val)
{
    return env_aset(nm, val);
}

ENV.store is an alias for ENV.[]=.

Creates, updates, or deletes the named environment variable, returning the value. Both name and value may be instances of String. See Valid Names and Values.

If the named environment variable does not exist:

If value is nil, does nothing.

ENV.clear
ENV['foo'] = nil # => nil
ENV.include?('foo') # => false
ENV.store('bar', nil) # => nil
ENV.include?('bar') # => false

If value is not nil, creates the environment variable with name and value:

# Create 'foo' using ENV.[]=.
ENV['foo'] = '0' # => '0'
ENV['foo'] # => '0'
# Create 'bar' using ENV.store.
ENV.store('bar', '1') # => '1'
ENV['bar'] # => '1'

If the named environment variable exists:

If value is not nil, updates the environment variable with value value:

# Update 'foo' using ENV.[]=.
ENV['foo'] = '2' # => '2'
ENV['foo'] # => '2'
# Update 'bar' using ENV.store.
ENV.store('bar', '3') # => '3'
ENV['bar'] # => '3'

If value is nil, deletes the environment variable:

# Delete 'foo' using ENV.[]=.
ENV['foo'] = nil # => nil
ENV.include?('foo') # => false
# Delete 'bar' using ENV.store.
ENV.store('bar', nil) # => nil
ENV.include?('bar') # => false

Raises an exception if name or value is invalid. See Invalid Names and Values.

ENV.assoc(name) → [name, value] or nil

::

hash.c View on GitHub

          
            static VALUE
env_assoc(VALUE env, VALUE key)
{
    const char *s, *e;

    s = env_name(key);
    e = getenv(s);
    if (e) return rb_assoc_new(key, env_str_new2(e));
    return Qnil;
}

Returns a 2-element Array containing the name and value of the environment variable for name if it exists:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.assoc('foo') # => ['foo', '0']

Returns nil if name is a valid String and there is no such environment variable.

Returns nil if name is the empty String or is a String containing character '='.

Raises an exception if name is a String containing the NUL character "\0":

ENV.assoc("\0") # Raises ArgumentError (bad environment variable name: contains null byte)

Raises an exception if name has an encoding that is not ASCII-compatible:

ENV.assoc("\xa1\xa1".force_encoding(Encoding::UTF_16LE))
# Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)

Raises an exception if name is not a String:

ENV.assoc(Object.new) # TypeError (no implicit conversion of Object into String)

ENV.clear → ENV

::

hash.c View on GitHub

          
            static VALUE
env_clear(VALUE _)
{
    return rb_env_clear();
}

Removes every environment variable; returns ENV:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.size # => 2
ENV.clear # => ENV
ENV.size # => 0

ENV.delete(name) { |name| block } → value

ENV.delete(missing_name) → nil

ENV.delete(missing_name) { |name| block } → block_value

::

hash.c View on GitHub

          
            static VALUE
env_delete_m(VALUE obj, VALUE name)
{
    VALUE val;

    val = env_delete(name);
    if (NIL_P(val) && rb_block_given_p()) val = rb_yield(name);
    return val;
}

Deletes the environment variable with name if it exists and returns its value:

ENV['foo'] = '0'
ENV.delete('foo') # => '0'

If a block is not given and the named environment variable does not exist, returns nil.

If a block given and the environment variable does not exist, yields name to the block and returns the value of the block:

ENV.delete('foo') { |name| name * 2 } # => "foofoo"

If a block given and the environment variable exists, deletes the environment variable and returns its value (ignoring the block):

ENV['foo'] = '0'
ENV.delete('foo') { |name| raise 'ignored' } # => "0"

Raises an exception if name is invalid. See Invalid Names and Values.

ENV.delete_if { |name, value| block } → ENV

ENV.delete_if → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_delete_if(VALUE ehash)
{
    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    env_reject_bang(ehash);
    return envtbl;
}

Yields each environment variable name and its value as a 2-element Array, deleting each environment variable for which the block returns a truthy value, and returning ENV (regardless of whether any deletions):

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.delete_if { |name, value| name.start_with?('b') } # => ENV
ENV # => {"foo"=>"0"}
ENV.delete_if { |name, value| name.start_with?('b') } # => ENV

Returns an Enumerator if no block given:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.delete_if # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:delete_if!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"foo"=>"0"}
e.each { |name, value| name.start_with?('b') } # => ENV

ENV.each { |name, value| block } → ENV

ENV.each → an_enumerator

ENV.each_pair { |name, value| block } → ENV

ENV.each_pair → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_each_pair(VALUE ehash)
{
    char **env;
    VALUE ary;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);

    ary = rb_ary_new();
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s) {
            rb_ary_push(ary, env_str_new(*env, s-*env));
            rb_ary_push(ary, env_str_new2(s+1));
        }
        env++;
    }
    FREE_ENVIRON(environ);

    if (rb_block_pair_yield_optimizable()) {
        for (i=0; i<RARRAY_LEN(ary); i+=2) {
            rb_yield_values(2, RARRAY_AREF(ary, i), RARRAY_AREF(ary, i+1));
        }
    }
    else {
        for (i=0; i<RARRAY_LEN(ary); i+=2) {
            rb_yield(rb_assoc_new(RARRAY_AREF(ary, i), RARRAY_AREF(ary, i+1)));
        }
    }
    return ehash;
}

Yields each environment variable name and its value as a 2-element Array:

h = {}
ENV.each_pair { |name, value| h[name] = value } # => ENV
h # => {"bar"=>"1", "foo"=>"0"}

Returns an Enumerator if no block given:

h = {}
e = ENV.each_pair # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_pair>
e.each { |name, value| h[name] = value } # => ENV
h # => {"bar"=>"1", "foo"=>"0"}

ENV.each_key { |name| block } → ENV

ENV.each_key → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_each_key(VALUE ehash)
{
    VALUE keys;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    keys = env_keys(FALSE);
    for (i=0; i<RARRAY_LEN(keys); i++) {
        rb_yield(RARRAY_AREF(keys, i));
    }
    return ehash;
}

Yields each environment variable name:

ENV.replace('foo' => '0', 'bar' => '1') # => ENV
names = []
ENV.each_key { |name| names.push(name) } # => ENV
names # => ["bar", "foo"]

Returns an Enumerator if no block given:

e = ENV.each_key # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_key>
names = []
e.each { |name| names.push(name) } # => ENV
names # => ["bar", "foo"]

ENV.each { |name, value| block } → ENV

ENV.each → an_enumerator

ENV.each_pair { |name, value| block } → ENV

ENV.each_pair → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_each_pair(VALUE ehash)
{
    char **env;
    VALUE ary;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);

    ary = rb_ary_new();
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s) {
            rb_ary_push(ary, env_str_new(*env, s-*env));
            rb_ary_push(ary, env_str_new2(s+1));
        }
        env++;
    }
    FREE_ENVIRON(environ);

    if (rb_block_pair_yield_optimizable()) {
        for (i=0; i<RARRAY_LEN(ary); i+=2) {
            rb_yield_values(2, RARRAY_AREF(ary, i), RARRAY_AREF(ary, i+1));
        }
    }
    else {
        for (i=0; i<RARRAY_LEN(ary); i+=2) {
            rb_yield(rb_assoc_new(RARRAY_AREF(ary, i), RARRAY_AREF(ary, i+1)));
        }
    }
    return ehash;
}

Yields each environment variable name and its value as a 2-element Array:

h = {}
ENV.each_pair { |name, value| h[name] = value } # => ENV
h # => {"bar"=>"1", "foo"=>"0"}

Returns an Enumerator if no block given:

h = {}
e = ENV.each_pair # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_pair>
e.each { |name, value| h[name] = value } # => ENV
h # => {"bar"=>"1", "foo"=>"0"}

ENV.each_value { |value| block } → ENV

ENV.each_value → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_each_value(VALUE ehash)
{
    VALUE values;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    values = env_values();
    for (i=0; i<RARRAY_LEN(values); i++) {
        rb_yield(RARRAY_AREF(values, i));
    }
    return ehash;
}

Yields each environment variable value:

ENV.replace('foo' => '0', 'bar' => '1') # => ENV
values = []
ENV.each_value { |value| values.push(value) } # => ENV
values # => ["1", "0"]

Returns an Enumerator if no block given:

e = ENV.each_value # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_value>
values = []
e.each { |value| values.push(value) } # => ENV
values # => ["1", "0"]

ENV.empty? → true or false

::

hash.c View on GitHub

          
            static VALUE
env_empty_p(VALUE _)
{
    char **env;

    env = GET_ENVIRON(environ);
    if (env[0] == 0) {
        FREE_ENVIRON(environ);
        return Qtrue;
    }
    FREE_ENVIRON(environ);
    return Qfalse;
}

Returns true when there are no environment variables, false otherwise:

ENV.clear
ENV.empty? # => true
ENV['foo'] = '0'
ENV.empty? # => false

ENV.except(*keys) → a_hash

::

hash.c View on GitHub

          
            static VALUE
env_except(int argc, VALUE *argv, VALUE _)
{
    int i;
    VALUE key, hash = env_to_hash();

    for (i = 0; i < argc; i++) {
        key = argv[i];
        rb_hash_delete(hash, key);
    }

    return hash;
}

Returns a hash except the given keys from ENV and their values.

ENV                       #=> {"LANG"=>"en_US.UTF-8", "TERM"=>"xterm-256color", "HOME"=>"/Users/rhc"}
ENV.except("TERM","HOME") #=> {"LANG"=>"en_US.UTF-8"}

ENV.fetch(name) → value

ENV.fetch(name, default) → value

ENV.fetch(name) { |name| block } → value

::

hash.c View on GitHub

          
            static VALUE
env_fetch(int argc, VALUE *argv, VALUE _)
{
    VALUE key;
    long block_given;
    const char *nam, *env;

    rb_check_arity(argc, 1, 2);
    key = argv[0];
    block_given = rb_block_given_p();
    if (block_given && argc == 2) {
        rb_warn("block supersedes default value argument");
    }
    nam = env_name(key);
    env = getenv(nam);
    if (!env) {
        if (block_given) return rb_yield(key);
        if (argc == 1) {
            rb_key_err_raise(rb_sprintf("key not found: \"%"PRIsVALUE"\"", key), envtbl, key);
        }
        return argv[1];
    }
    return env_name_new(nam, env);
}

If name is the name of an environment variable, returns its value:

ENV['foo'] = '0'
ENV.fetch('foo') # => '0'

Otherwise if a block is given (but not a default value), yields name to the block and returns the block’s return value:

ENV.fetch('foo') { |name| :need_not_return_a_string } # => :need_not_return_a_string

Otherwise if a default value is given (but not a block), returns the default value:

ENV.delete('foo')
ENV.fetch('foo', :default_need_not_be_a_string) # => :default_need_not_be_a_string

If the environment variable does not exist and both default and block are given, issues a warning (“warning: block supersedes default value argument”), yields name to the block, and returns the block’s return value:

ENV.fetch('foo', :default) { |name| :block_return } # => :block_return

Raises KeyError if name is valid, but not found, and neither default value nor block is given:

ENV.fetch('foo') # Raises KeyError (key not found: "foo")

Raises an exception if name is invalid. See Invalid Names and Values.

ENV.select { |name, value| block } → hash of name/value pairs

ENV.select → an_enumerator

ENV.filter { |name, value| block } → hash of name/value pairs

ENV.filter → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_select(VALUE ehash)
{
    VALUE result;
    VALUE keys;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    result = rb_hash_new();
    keys = env_keys(FALSE);
    for (i = 0; i < RARRAY_LEN(keys); ++i) {
        VALUE key = RARRAY_AREF(keys, i);
        VALUE val = rb_f_getenv(Qnil, key);
        if (!NIL_P(val)) {
            if (RTEST(rb_yield_values(2, key, val))) {
                rb_hash_aset(result, key, val);
            }
        }
    }
    RB_GC_GUARD(keys);

    return result;
}

ENV.filter is an alias for ENV.select.

Yields each environment variable name and its value as a 2-element Array, returning a Hash of the names and values for which the block returns a truthy value:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.select { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
ENV.filter { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}

Returns an Enumerator if no block given:

e = ENV.select # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:select>
e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
e = ENV.filter # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:filter>
e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}

ENV.select! { |name, value| block } → ENV or nil

ENV.select! → an_enumerator

ENV.filter! { |name, value| block } → ENV or nil

ENV.filter! → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_select_bang(VALUE ehash)
{
    VALUE keys;
    long i;
    int del = 0;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    keys = env_keys(FALSE);
    RBASIC_CLEAR_CLASS(keys);
    for (i=0; i<RARRAY_LEN(keys); i++) {
        VALUE val = rb_f_getenv(Qnil, RARRAY_AREF(keys, i));
        if (!NIL_P(val)) {
            if (!RTEST(rb_yield_values(2, RARRAY_AREF(keys, i), val))) {
                env_delete(RARRAY_AREF(keys, i));
                del++;
            }
        }
    }
    RB_GC_GUARD(keys);
    if (del == 0) return Qnil;
    return envtbl;
}

ENV.filter! is an alias for ENV.select!.

Yields each environment variable name and its value as a 2-element Array, deleting each entry for which the block returns false or nil, and returning ENV if any deletions made, or nil otherwise:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.select! { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
ENV.select! { |name, value| true } # => nil

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.filter! { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
ENV.filter! { |name, value| true } # => nil

Returns an Enumerator if no block given:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.select! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:select!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
e.each { |name, value| true } # => nil

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.filter! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:filter!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
e.each { |name, value| true } # => nil

ENV.freeze

::

hash.c View on GitHub

          
            static VALUE
env_freeze(VALUE self)
{
    rb_raise(rb_eTypeError, "cannot freeze ENV");
    UNREACHABLE_RETURN(self);
}

Raises an exception:

ENV.freeze # Raises TypeError (cannot freeze ENV)

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_key(VALUE env, VALUE key)
{
    const char *s;

    s = env_name(key);
    if (getenv(s)) return Qtrue;
    return Qfalse;
}

ENV.has_key?, ENV.member?, and ENV.key? are aliases for ENV.include?.

Returns true if there is an environment variable with the given name:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.include?('foo') # => true

Returns false if name is a valid String and there is no such environment variable:

ENV.include?('baz') # => false

Returns false if name is the empty String or is a String containing character '=':

ENV.include?('') # => false
ENV.include?('=') # => false

Raises an exception if name is a String containing the NUL character "\0":

ENV.include?("\0") # Raises ArgumentError (bad environment variable name: contains null byte)

Raises an exception if name has an encoding that is not ASCII-compatible:

ENV.include?("\xa1\xa1".force_encoding(Encoding::UTF_16LE))
# Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)

Raises an exception if name is not a String:

ENV.include?(Object.new) # TypeError (no implicit conversion of Object into String)

ENV.value?(value) → true or false

ENV.has_value?(value) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_value(VALUE dmy, VALUE obj)
{
    char **env;

    obj = rb_check_string_type(obj);
    if (NIL_P(obj)) return Qnil;
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s++) {
            long len = strlen(s);
            if (RSTRING_LEN(obj) == len && strncmp(s, RSTRING_PTR(obj), len) == 0) {
                FREE_ENVIRON(environ);
                return Qtrue;
            }
        }
        env++;
    }
    FREE_ENVIRON(environ);
    return Qfalse;
}

Returns true if value is the value for some environment variable name, false otherwise:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.value?('0') # => true
ENV.has_value?('0') # => true
ENV.value?('2') # => false
ENV.has_value?('2') # => false

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_key(VALUE env, VALUE key)
{
    const char *s;

    s = env_name(key);
    if (getenv(s)) return Qtrue;
    return Qfalse;
}

ENV.has_key?, ENV.member?, and ENV.key? are aliases for ENV.include?.

Returns true if there is an environment variable with the given name:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.include?('foo') # => true

Returns false if name is a valid String and there is no such environment variable:

ENV.include?('baz') # => false

Returns false if name is the empty String or is a String containing character '=':

ENV.include?('') # => false
ENV.include?('=') # => false

Raises an exception if name is a String containing the NUL character "\0":

ENV.include?("\0") # Raises ArgumentError (bad environment variable name: contains null byte)

Raises an exception if name has an encoding that is not ASCII-compatible:

ENV.include?("\xa1\xa1".force_encoding(Encoding::UTF_16LE))
# Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)

Raises an exception if name is not a String:

ENV.include?(Object.new) # TypeError (no implicit conversion of Object into String)

ENV.inspect → a_string

::

hash.c View on GitHub

          
            static VALUE
env_inspect(VALUE _)
{
    char **env;
    VALUE str, i;

    str = rb_str_buf_new2("{");
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');

        if (env != environ) {
            rb_str_buf_cat2(str, ", ");
        }
        if (s) {
            rb_str_buf_cat2(str, "\"");
            rb_str_buf_cat(str, *env, s-*env);
            rb_str_buf_cat2(str, "\"=>");
            i = rb_inspect(rb_str_new2(s+1));
            rb_str_buf_append(str, i);
        }
        env++;
    }
    FREE_ENVIRON(environ);
    rb_str_buf_cat2(str, "}");

    return str;
}

Returns the contents of the environment as a String:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.inspect # => "{\"bar\"=>\"1\", \"foo\"=>\"0\"}"

ENV.invert → hash of value/name pairs

::

hash.c View on GitHub

          
            static VALUE
env_invert(VALUE _)
{
    return rb_hash_invert(env_to_hash());
}

Returns a Hash whose keys are the ENV values, and whose values are the corresponding ENV names:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.invert # => {"1"=>"bar", "0"=>"foo"}

For a duplicate ENV value, overwrites the hash entry:

ENV.replace('foo' => '0', 'bar' => '0')
ENV.invert # => {"0"=>"foo"}

Note that the order of the ENV processing is OS-dependent, which means that the order of overwriting is also OS-dependent. See About Ordering.

ENV.keep_if { |name, value| block } → ENV

ENV.keep_if → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_keep_if(VALUE ehash)
{
    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    env_select_bang(ehash);
    return envtbl;
}

Yields each environment variable name and its value as a 2-element Array, deleting each environment variable for which the block returns false or nil, and returning ENV:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.keep_if { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}

Returns an Enumerator if no block given:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.keep_if # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:keep_if>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}

ENV.key(value) → name or nil

::

hash.c View on GitHub

          
            static VALUE
env_key(VALUE dmy, VALUE value)
{
    char **env;
    VALUE str;

    SafeStringValue(value);
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s++) {
            long len = strlen(s);
            if (RSTRING_LEN(value) == len && strncmp(s, RSTRING_PTR(value), len) == 0) {
                str = env_str_new(*env, s-*env-1);
                FREE_ENVIRON(environ);
                return str;
            }
        }
        env++;
    }
    FREE_ENVIRON(environ);
    return Qnil;
}

Returns the name of the first environment variable with value, if it exists:

ENV.replace('foo' => '0', 'bar' => '0')
ENV.key('0') # => "foo"

The order in which environment variables are examined is OS-dependent. See About Ordering.

Returns nil if there is no such value.

Raises an exception if value is invalid:

ENV.key(Object.new) # raises TypeError (no implicit conversion of Object into String)

See Invalid Names and Values.

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_key(VALUE env, VALUE key)
{
    const char *s;

    s = env_name(key);
    if (getenv(s)) return Qtrue;
    return Qfalse;
}

ENV.has_key?, ENV.member?, and ENV.key? are aliases for ENV.include?.

Returns true if there is an environment variable with the given name:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.include?('foo') # => true

Returns false if name is a valid String and there is no such environment variable:

ENV.include?('baz') # => false

Returns false if name is the empty String or is a String containing character '=':

ENV.include?('') # => false
ENV.include?('=') # => false

Raises an exception if name is a String containing the NUL character "\0":

ENV.include?("\0") # Raises ArgumentError (bad environment variable name: contains null byte)

Raises an exception if name has an encoding that is not ASCII-compatible:

ENV.include?("\xa1\xa1".force_encoding(Encoding::UTF_16LE))
# Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)

Raises an exception if name is not a String:

ENV.include?(Object.new) # TypeError (no implicit conversion of Object into String)

ENV.keys → array of names

::

hash.c View on GitHub

          
            static VALUE
env_f_keys(VALUE _)
{
    return env_keys(FALSE);
}

Returns all variable names in an Array:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.keys # => ['bar', 'foo']

The order of the names is OS-dependent. See About Ordering.

Returns the empty Array if ENV is empty.

ENV.length → an_integer

ENV.size → an_integer

::

hash.c View on GitHub

          
            static VALUE
env_size(VALUE _)
{
    int i;
    char **env;

    env = GET_ENVIRON(environ);
    for (i=0; env[i]; i++)
        ;
    FREE_ENVIRON(environ);
    return INT2FIX(i);
}

Returns the count of environment variables:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.length # => 2
ENV.size # => 2

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_key(VALUE env, VALUE key)
{
    const char *s;

    s = env_name(key);
    if (getenv(s)) return Qtrue;
    return Qfalse;
}

ENV.has_key?, ENV.member?, and ENV.key? are aliases for ENV.include?.

Returns true if there is an environment variable with the given name:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.include?('foo') # => true

Returns false if name is a valid String and there is no such environment variable:

ENV.include?('baz') # => false

Returns false if name is the empty String or is a String containing character '=':

ENV.include?('') # => false
ENV.include?('=') # => false

Raises an exception if name is a String containing the NUL character "\0":

ENV.include?("\0") # Raises ArgumentError (bad environment variable name: contains null byte)

Raises an exception if name has an encoding that is not ASCII-compatible:

ENV.include?("\xa1\xa1".force_encoding(Encoding::UTF_16LE))
# Raises ArgumentError (bad environment variable name: ASCII incompatible encoding: UTF-16LE)

Raises an exception if name is not a String:

ENV.include?(Object.new) # TypeError (no implicit conversion of Object into String)

ENV.update(hash) → ENV

ENV.update(hash) { |name, env_val, hash_val| block } → ENV

ENV.merge!(hash) → ENV

ENV.merge!(hash) { |name, env_val, hash_val| block } → ENV

::

hash.c View on GitHub

          
            static VALUE
env_update(VALUE env, VALUE hash)
{
    if (env == hash) return env;
    hash = to_hash(hash);
    rb_foreach_func *func = rb_block_given_p() ?
        env_update_block_i : env_update_i;
    rb_hash_foreach(hash, func, 0);
    return env;
}

ENV.update is an alias for ENV.merge!.

Adds to ENV each key/value pair in the given hash; returns ENV:

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:

ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}

For an already-existing name, if no block given, overwrites the ENV value:

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:

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);

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):

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.

ENV.rassoc(value) → [name, value] or nil

::

hash.c View on GitHub

          
            static VALUE
env_rassoc(VALUE dmy, VALUE obj)
{
    char **env;

    obj = rb_check_string_type(obj);
    if (NIL_P(obj)) return Qnil;
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s++) {
            long len = strlen(s);
            if (RSTRING_LEN(obj) == len && strncmp(s, RSTRING_PTR(obj), len) == 0) {
                VALUE result = rb_assoc_new(rb_str_new(*env, s-*env-1), obj);
                FREE_ENVIRON(environ);
                return result;
            }
        }
        env++;
    }
    FREE_ENVIRON(environ);
    return Qnil;
}

Returns a 2-element Array containing the name and value of the first found environment variable that has value value, if one exists:

ENV.replace('foo' => '0', 'bar' => '0')
ENV.rassoc('0') # => ["bar", "0"]

The order in which environment variables are examined is OS-dependent. See About Ordering.

Returns nil if there is no such environment variable.

ENV.rehash → nil

::

hash.c View on GitHub

          
            static VALUE
env_none(VALUE _)
{
    return Qnil;
}

(Provided for compatibility with Hash.)

Does not modify ENV; returns nil.

ENV.reject { |name, value| block } → hash of name/value pairs

ENV.reject → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_reject(VALUE _)
{
    return rb_hash_delete_if(env_to_hash());
}

Yields each environment variable name and its value as a 2-element Array. Returns a Hash whose items are determined by the block. When the block returns a truthy value, the name/value pair is added to the return Hash; otherwise the pair is ignored:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.reject { |name, value| name.start_with?('b') } # => {"foo"=>"0"}

Returns an Enumerator if no block given:

e = ENV.reject
e.each { |name, value| name.start_with?('b') } # => {"foo"=>"0"}

ENV.reject! { |name, value| block } → ENV or nil

ENV.reject! → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_reject_bang(VALUE ehash)
{
    VALUE keys;
    long i;
    int del = 0;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    keys = env_keys(FALSE);
    RBASIC_CLEAR_CLASS(keys);
    for (i=0; i<RARRAY_LEN(keys); i++) {
        VALUE val = rb_f_getenv(Qnil, RARRAY_AREF(keys, i));
        if (!NIL_P(val)) {
            if (RTEST(rb_yield_values(2, RARRAY_AREF(keys, i), val))) {
                env_delete(RARRAY_AREF(keys, i));
                del++;
            }
        }
    }
    RB_GC_GUARD(keys);
    if (del == 0) return Qnil;
    return envtbl;
}

Similar to ENV.delete_if, but returns nil if no changes were made.

Yields each environment variable name and its value as a 2-element Array, deleting each environment variable for which the block returns a truthy value, and returning ENV (if any deletions) or nil (if not):

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.reject! { |name, value| name.start_with?('b') } # => ENV
ENV # => {"foo"=>"0"}
ENV.reject! { |name, value| name.start_with?('b') } # => nil

Returns an Enumerator if no block given:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.reject! # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:reject!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"foo"=>"0"}
e.each { |name, value| name.start_with?('b') } # => nil

ENV.replace(hash) → ENV

::

hash.c View on GitHub

          
            static VALUE
env_replace(VALUE env, VALUE hash)
{
    VALUE keys;
    long i;

    keys = env_keys(TRUE);
    if (env == hash) return env;
    hash = to_hash(hash);
    rb_hash_foreach(hash, env_replace_i, keys);

    for (i=0; i<RARRAY_LEN(keys); i++) {
        env_delete(RARRAY_AREF(keys, i));
    }
    RB_GC_GUARD(keys);
    return env;
}

Replaces the entire content of the environment variables with the name/value pairs in the given hash; returns ENV.

Replaces the content of ENV with the given pairs:

ENV.replace('foo' => '0', 'bar' => '1') # => ENV
ENV.to_hash # => {"bar"=>"1", "foo"=>"0"}

Raises an exception if a name or value is invalid (see Invalid Names and Values):

ENV.replace('foo' => '0', :bar => '1') # Raises TypeError (no implicit conversion of Symbol into String)
ENV.replace('foo' => '0', 'bar' => 1) # Raises TypeError (no implicit conversion of Integer into String)
ENV.to_hash # => {"bar"=>"1", "foo"=>"0"}

ENV.select { |name, value| block } → hash of name/value pairs

ENV.select → an_enumerator

ENV.filter { |name, value| block } → hash of name/value pairs

ENV.filter → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_select(VALUE ehash)
{
    VALUE result;
    VALUE keys;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    result = rb_hash_new();
    keys = env_keys(FALSE);
    for (i = 0; i < RARRAY_LEN(keys); ++i) {
        VALUE key = RARRAY_AREF(keys, i);
        VALUE val = rb_f_getenv(Qnil, key);
        if (!NIL_P(val)) {
            if (RTEST(rb_yield_values(2, key, val))) {
                rb_hash_aset(result, key, val);
            }
        }
    }
    RB_GC_GUARD(keys);

    return result;
}

ENV.filter is an alias for ENV.select.

Yields each environment variable name and its value as a 2-element Array, returning a Hash of the names and values for which the block returns a truthy value:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.select { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
ENV.filter { |name, value| name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}

Returns an Enumerator if no block given:

e = ENV.select # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:select>
e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}
e = ENV.filter # => #<Enumerator: {"bar"=>"1", "baz"=>"2", "foo"=>"0"}:filter>
e.each { |name, value | name.start_with?('b') } # => {"bar"=>"1", "baz"=>"2"}

ENV.select! { |name, value| block } → ENV or nil

ENV.select! → an_enumerator

ENV.filter! { |name, value| block } → ENV or nil

ENV.filter! → an_enumerator

::

hash.c View on GitHub

          
            static VALUE
env_select_bang(VALUE ehash)
{
    VALUE keys;
    long i;
    int del = 0;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    keys = env_keys(FALSE);
    RBASIC_CLEAR_CLASS(keys);
    for (i=0; i<RARRAY_LEN(keys); i++) {
        VALUE val = rb_f_getenv(Qnil, RARRAY_AREF(keys, i));
        if (!NIL_P(val)) {
            if (!RTEST(rb_yield_values(2, RARRAY_AREF(keys, i), val))) {
                env_delete(RARRAY_AREF(keys, i));
                del++;
            }
        }
    }
    RB_GC_GUARD(keys);
    if (del == 0) return Qnil;
    return envtbl;
}

ENV.filter! is an alias for ENV.select!.

Yields each environment variable name and its value as a 2-element Array, deleting each entry for which the block returns false or nil, and returning ENV if any deletions made, or nil otherwise:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.select! { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
ENV.select! { |name, value| true } # => nil

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.filter! { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
ENV.filter! { |name, value| true } # => nil

Returns an Enumerator if no block given:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.select! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:select!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
e.each { |name, value| true } # => nil

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
e = ENV.filter! # => #<Enumerator: {"bar"=>"1", "baz"=>"2"}:filter!>
e.each { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}
e.each { |name, value| true } # => nil

ENV.shift → [name, value] or nil

::

hash.c View on GitHub

          
            static VALUE
env_shift(VALUE _)
{
    char **env;
    VALUE result = Qnil;

    env = GET_ENVIRON(environ);
    if (*env) {
        char *s = strchr(*env, '=');
        if (s) {
            VALUE key = env_str_new(*env, s-*env);
            VALUE val = env_str_new2(getenv(RSTRING_PTR(key)));
            env_delete(key);
            result = rb_assoc_new(key, val);
        }
    }
    FREE_ENVIRON(environ);
    return result;
}

Removes the first environment variable from ENV and returns a 2-element Array containing its name and value:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.to_hash # => {'bar' => '1', 'foo' => '0'}
ENV.shift # => ['bar', '1']
ENV.to_hash # => {'foo' => '0'}

Exactly which environment variable is “first” is OS-dependent. See About Ordering.

Returns nil if the environment is empty.

ENV.length → an_integer

ENV.size → an_integer

::

hash.c View on GitHub

          
            static VALUE
env_size(VALUE _)
{
    int i;
    char **env;

    env = GET_ENVIRON(environ);
    for (i=0; env[i]; i++)
        ;
    FREE_ENVIRON(environ);
    return INT2FIX(i);
}

Returns the count of environment variables:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.length # => 2
ENV.size # => 2

ENV.slice(*names) → hash of name/value pairs

::

hash.c View on GitHub

          
            static VALUE
env_slice(int argc, VALUE *argv, VALUE _)
{
    int i;
    VALUE key, value, result;

    if (argc == 0) {
        return rb_hash_new();
    }
    result = rb_hash_new_with_size(argc);

    for (i = 0; i < argc; i++) {
        key = argv[i];
        value = rb_f_getenv(Qnil, key);
        if (value != Qnil)
            rb_hash_aset(result, key, value);
    }

    return result;
}

Returns a Hash of the given ENV names and their corresponding values:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2', 'bat' => '3')
ENV.slice('foo', 'baz') # => {"foo"=>"0", "baz"=>"2"}
ENV.slice('baz', 'foo') # => {"baz"=>"2", "foo"=>"0"}

Raises an exception if any of the names is invalid (see Invalid Names and Values):

ENV.slice('foo', 'bar', :bat) # Raises TypeError (no implicit conversion of Symbol into String)

ENV[name] = value → value

ENV.store(name, value) → value

::

hash.c View on GitHub

          
            static VALUE
env_aset_m(VALUE obj, VALUE nm, VALUE val)
{
    return env_aset(nm, val);
}

ENV.store is an alias for ENV.[]=.

Creates, updates, or deletes the named environment variable, returning the value. Both name and value may be instances of String. See Valid Names and Values.

If the named environment variable does not exist:

If value is nil, does nothing.

ENV.clear
ENV['foo'] = nil # => nil
ENV.include?('foo') # => false
ENV.store('bar', nil) # => nil
ENV.include?('bar') # => false

If value is not nil, creates the environment variable with name and value:

# Create 'foo' using ENV.[]=.
ENV['foo'] = '0' # => '0'
ENV['foo'] # => '0'
# Create 'bar' using ENV.store.
ENV.store('bar', '1') # => '1'
ENV['bar'] # => '1'

If the named environment variable exists:

If value is not nil, updates the environment variable with value value:

# Update 'foo' using ENV.[]=.
ENV['foo'] = '2' # => '2'
ENV['foo'] # => '2'
# Update 'bar' using ENV.store.
ENV.store('bar', '3') # => '3'
ENV['bar'] # => '3'

If value is nil, deletes the environment variable:

# Delete 'foo' using ENV.[]=.
ENV['foo'] = nil # => nil
ENV.include?('foo') # => false
# Delete 'bar' using ENV.store.
ENV.store('bar', nil) # => nil
ENV.include?('bar') # => false

Raises an exception if name or value is invalid. See Invalid Names and Values.

ENV.to_a → array of 2-element arrays

::

hash.c View on GitHub

          
            static VALUE
env_to_a(VALUE _)
{
    char **env;
    VALUE ary;

    ary = rb_ary_new();
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s) {
            rb_ary_push(ary, rb_assoc_new(env_str_new(*env, s-*env),
                                          env_str_new2(s+1)));
        }
        env++;
    }
    FREE_ENVIRON(environ);
    return ary;
}

Returns the contents of ENV as an Array of 2-element Arrays, each of which is a name/value pair:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.to_a # => [["bar", "1"], ["foo", "0"]]

ENV.to_h → hash of name/value pairs

ENV.to_h {|name, value| block } → hash of name/value pairs

::

hash.c View on GitHub

          
            static VALUE
env_to_h(VALUE _)
{
    VALUE hash = env_to_hash();
    if (rb_block_given_p()) {
        hash = rb_hash_to_h_block(hash);
    }
    return hash;
}

With no block, returns a Hash containing all name/value pairs from ENV:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.to_h # => {"bar"=>"1", "foo"=>"0"}

With a block, returns a Hash whose items are determined by the block. Each name/value pair in ENV is yielded to the block. The block must return a 2-element Array (name/value pair) that is added to the return Hash as a key and value:

ENV.to_h { |name, value| [name.to_sym, value.to_i] } # => {:bar=>1, :foo=>0}

Raises an exception if the block does not return an Array:

ENV.to_h { |name, value| name } # Raises TypeError (wrong element type String (expected array))

Raises an exception if the block returns an Array of the wrong size:

ENV.to_h { |name, value| [name] } # Raises ArgumentError (element has wrong array length (expected 2, was 1))

ENV.to_hash → hash of name/value pairs

::

hash.c View on GitHub

          
            static VALUE
env_f_to_hash(VALUE _)
{
    return env_to_hash();
}

Returns a Hash containing all name/value pairs from ENV:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.to_hash # => {"bar"=>"1", "foo"=>"0"}

ENV.to_s → "ENV"

::

hash.c View on GitHub

          
            static VALUE
env_to_s(VALUE _)
{
    return rb_usascii_str_new2("ENV");
}

Returns String ‘ENV’:

ENV.to_s # => "ENV"

ENV.update(hash) → ENV

ENV.update(hash) { |name, env_val, hash_val| block } → ENV

ENV.merge!(hash) → ENV

ENV.merge!(hash) { |name, env_val, hash_val| block } → ENV

::

hash.c View on GitHub

          
            static VALUE
env_update(VALUE env, VALUE hash)
{
    if (env == hash) return env;
    hash = to_hash(hash);
    rb_foreach_func *func = rb_block_given_p() ?
        env_update_block_i : env_update_i;
    rb_hash_foreach(hash, func, 0);
    return env;
}

ENV.update is an alias for ENV.merge!.

Adds to ENV each key/value pair in the given hash; returns ENV:

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:

ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}

For an already-existing name, if no block given, overwrites the ENV value:

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:

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);

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):

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.

ENV.value?(value) → true or false

ENV.has_value?(value) → true or false

::

hash.c View on GitHub

          
            static VALUE
env_has_value(VALUE dmy, VALUE obj)
{
    char **env;

    obj = rb_check_string_type(obj);
    if (NIL_P(obj)) return Qnil;
    env = GET_ENVIRON(environ);
    while (*env) {
        char *s = strchr(*env, '=');
        if (s++) {
            long len = strlen(s);
            if (RSTRING_LEN(obj) == len && strncmp(s, RSTRING_PTR(obj), len) == 0) {
                FREE_ENVIRON(environ);
                return Qtrue;
            }
        }
        env++;
    }
    FREE_ENVIRON(environ);
    return Qfalse;
}

Returns true if value is the value for some environment variable name, false otherwise:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.value?('0') # => true
ENV.has_value?('0') # => true
ENV.value?('2') # => false
ENV.has_value?('2') # => false

ENV.values → array of values

::

hash.c View on GitHub

          
            static VALUE
env_f_values(VALUE _)
{
    return env_values();
}

Returns all environment variable values in an Array:

ENV.replace('foo' => '0', 'bar' => '1')
ENV.values # => ['1', '0']

The order of the values is OS-dependent. See About Ordering.

Returns the empty Array if ENV is empty.

ENV.values_at(*names) → array of values

::

hash.c View on GitHub

          
            static VALUE
env_values_at(int argc, VALUE *argv, VALUE _)
{
    VALUE result;
    long i;

    result = rb_ary_new();
    for (i=0; i<argc; i++) {
        rb_ary_push(result, rb_f_getenv(Qnil, argv[i]));
    }
    return result;
}

Returns an Array containing the environment variable values associated with the given names:

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.values_at('foo', 'baz') # => ["0", "2"]

Returns nil in the Array for each name that is not an ENV name:

ENV.values_at('foo', 'bat', 'bar', 'bam') # => ["0", nil, "1", nil]

Returns an empty Array if no names given.

Raises an exception if any name is invalid. See Invalid Names and Values.

Interaction with the Operating System

Names and Values

Valid Names and Values

Invalid Names and Values

About Ordering

About the Examples

ENV[name] → value

ENV[name] = value → value

ENV.store(name, value) → value

ENV.assoc(name) → [name, value] or nil

ENV.clear → ENV

ENV.delete(name) → value

ENV.delete(name) { |name| block } → value

ENV.delete(missing_name) → nil

ENV.delete(missing_name) { |name| block } → block_value

ENV.delete_if { |name, value| block } → ENV

ENV.delete_if → an_enumerator

ENV.each { |name, value| block } → ENV

ENV.each → an_enumerator

ENV.each_pair { |name, value| block } → ENV

ENV.each_pair → an_enumerator

ENV.each_key { |name| block } → ENV

ENV.each_key → an_enumerator

ENV.each { |name, value| block } → ENV

ENV.each → an_enumerator

ENV.each_pair { |name, value| block } → ENV

ENV.each_pair → an_enumerator

ENV.each_value { |value| block } → ENV

ENV.each_value → an_enumerator

ENV.empty? → true or false

ENV.except(*keys) → a_hash

ENV.fetch(name) → value

ENV.fetch(name, default) → value

ENV.fetch(name) { |name| block } → value

ENV.select { |name, value| block } → hash of name/value pairs

ENV.select → an_enumerator

ENV.filter { |name, value| block } → hash of name/value pairs

ENV.filter → an_enumerator

ENV.select! { |name, value| block } → ENV or nil

ENV.select! → an_enumerator

ENV.filter! { |name, value| block } → ENV or nil

ENV.filter! → an_enumerator

ENV.freeze

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

ENV.value?(value) → true or false

ENV.has_value?(value) → true or false

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

ENV.inspect → a_string

ENV.invert → hash of value/name pairs

ENV.keep_if { |name, value| block } → ENV

ENV.keep_if → an_enumerator

ENV.key(value) → name or nil

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

ENV.keys → array of names

ENV.length → an_integer

ENV.size → an_integer

ENV.include?(name) → true or false

ENV.has_key?(name) → true or false

ENV.member?(name) → true or false

ENV.key?(name) → true or false

ENV.update(hash) → ENV

ENV.update(hash) { |name, env_val, hash_val| block } → ENV

ENV.merge!(hash) → ENV

ENV.merge!(hash) { |name, env_val, hash_val| block } → ENV

ENV.rassoc(value) → [name, value] or nil

ENV.rehash → nil

ENV.reject { |name, value| block } → hash of name/value pairs

ENV.reject → an_enumerator

ENV.reject! { |name, value| block } → ENV or nil

ENV.reject! → an_enumerator