Class: ENV (Ruby 2.3.4)

    In Files

    • hash.c

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    ENV

    ENV is a hash-like accessor for environment variables.

    Public Class Methods

    ENV[name] → value click to toggle source

    Retrieves the value for environment variable name as a String. Returns nil if the named variable does not exist.

     
                   static VALUE
    rb_f_getenv(VALUE obj, VALUE name)
    {
        const char *nam, *env;
    
        nam = env_name(name);
        env = getenv(nam);
        if (env) {
            if (ENVMATCH(nam, PATH_ENV) && !env_path_tainted(env)) {
                return env_path_str_new(env);
            }
            return env_str_new2(env);
        }
        return Qnil;
    }
                
    ENV[name] = value click to toggle source

    Sets the environment variable name to value. If the value given is nil the environment variable is deleted. name must be a string.

     
                   static VALUE
    env_aset(VALUE obj, VALUE nm, VALUE val)
    {
        char *name, *value;
    
        if (NIL_P(val)) {
            env_delete(obj, nm);
            return Qnil;
        }
        SafeStringValue(nm);
        SafeStringValue(val);
        /* nm can be modified in `val.to_str`, don't get `name` before
         * check for `val` */
        get_env_ptr(name, nm);
        get_env_ptr(value, val);
    
        ruby_setenv(name, value);
        if (ENVMATCH(name, PATH_ENV)) {
            RB_GC_GUARD(nm);
            if (OBJ_TAINTED(val)) {
                /* already tainted, no check */
                path_tainted = 1;
                return val;
            }
            else {
                path_tainted_p(value);
            }
        }
        return val;
    }
                
    assoc(name) → Array or nil click to toggle source

    Returns an Array of the name and value of the environment variable with name or nil if the name cannot be found.

     
                   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, rb_tainted_str_new2(e));
        return Qnil;
    }
                
    clear click to toggle source

    Removes every environment variable.

     
                   VALUE
    rb_env_clear(void)
    {
        VALUE keys;
        long i;
    
        keys = env_keys();
        for (i=0; i<RARRAY_LEN(keys); i++) {
            VALUE val = rb_f_getenv(Qnil, RARRAY_AREF(keys, i));
            if (!NIL_P(val)) {
                env_delete(Qnil, RARRAY_AREF(keys, i));
            }
        }
        RB_GC_GUARD(keys);
        return envtbl;
    }
                
    delete(name) → value click to toggle source
    delete(name) { |name| } → value

    Deletes the environment variable with name and returns the value of the variable. If a block is given it will be called when the named environment does not exist.

     
                   static VALUE
    env_delete_m(VALUE obj, VALUE name)
    {
        VALUE val;
    
        val = env_delete(obj, name);
        if (NIL_P(val) && rb_block_given_p()) rb_yield(name);
        return val;
    }
                
    delete_if { |name, value| } → Hash click to toggle source
    delete_if → Enumerator

    Deletes every environment variable for which the block evaluates to true.

    If no block is given an enumerator is returned instead.

     
                   static VALUE
    env_delete_if(VALUE ehash)
    {
        RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
        env_reject_bang(ehash);
        return envtbl;
    }
                
    each { |name, value| } → Hash click to toggle source
    each → Enumerator
    each_pair { |name, value| } → Hash
    each_pair → Enumerator

    Yields each environment variable name and value.

    If no block is given an Enumerator is returned.

     
                   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_arity() > 1) {
            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;
    }
                
    each_key { |name| } → Hash click to toggle source
    each_key → Enumerator

    Yields each environment variable name.

    An Enumerator is returned if no block is given.

     
                   static VALUE
    env_each_key(VALUE ehash)
    {
        VALUE keys;
        long i;
    
        RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
        keys = env_keys();
        for (i=0; i<RARRAY_LEN(keys); i++) {
            rb_yield(RARRAY_AREF(keys, i));
        }
        return ehash;
    }
                
    each_pair { |name, value| } → Hash click to toggle source
    each_pair → Enumerator

    Yields each environment variable name and value.

    If no block is given an Enumerator is returned.

     
                   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_arity() > 1) {
            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;
    }
                
    each_value { |value| } → Hash click to toggle source
    each_value → Enumerator

    Yields each environment variable value.

    An Enumerator is returned if no block was given.

     
                   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;
    }
                
    empty? → true or false click to toggle source

    Returns true when there are no environment variables

     
                   static VALUE
    env_empty_p(void)
    {
        char **env;
    
        env = GET_ENVIRON(environ);
        if (env[0] == 0) {
            FREE_ENVIRON(environ);
            return Qtrue;
        }
        FREE_ENVIRON(environ);
        return Qfalse;
    }
                
    fetch(name) → value click to toggle source
    fetch(name, default) → value
    fetch(name) { |missing_name| ... } → value

    Retrieves the environment variable name.

    If the given name does not exist and neither default nor a block a provided an IndexError is raised. If a block is given it is called with the missing name to provide a value. If a default value is given it will be returned when no block is given.

     
                   static VALUE
    env_fetch(int argc, VALUE *argv)
    {
        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_raise(rb_eKeyError, "key not found: \"%"PRIsVALUE"\"", key);
            }
            return argv[1];
        }
        if (ENVMATCH(nam, PATH_ENV) && !env_path_tainted(env))
            return env_path_str_new(env);
        return env_str_new2(env);
    }
                
    has_key?(name) → true or false click to toggle source

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

     
                   static VALUE
    env_has_key(VALUE env, VALUE key)
    {
        const char *s;
    
        s = env_name(key);
        if (getenv(s)) return Qtrue;
        return Qfalse;
    }
                
    has_value?(value) → true or false click to toggle source

    Returns true if there is an environment variable with the given value.

     
                   static VALUE
    env_has_value(VALUE dmy, VALUE obj)
    {
        char **env;
    
        obj = rb_check_string_type(obj);
        if (NIL_P(obj)) return Qnil;
        rb_check_safe_obj(obj);
        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;
    }
                
    include?(name) → true or false click to toggle source

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

     
                   static VALUE
    env_has_key(VALUE env, VALUE key)
    {
        const char *s;
    
        s = env_name(key);
        if (getenv(s)) return Qtrue;
        return Qfalse;
    }
                
    index(value) → key click to toggle source

    Deprecated method that is equivalent to ::key

     
                   static VALUE
    env_index(VALUE dmy, VALUE value)
    {
        rb_warn("ENV.index is deprecated; use ENV.key");
        return env_key(dmy, value);
    }
                
    inspect → string click to toggle source

    Returns the contents of the environment as a String.

     
                   static VALUE
    env_inspect(void)
    {
        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, "}");
        OBJ_TAINT(str);
    
        return str;
    }
                
    invert → Hash click to toggle source

    Returns a new hash created by using environment variable names as values and values as names.

     
                   static VALUE
    env_invert(void)
    {
        return rb_hash_invert(env_to_hash());
    }
                
    keep_if { |name, value| } → Hash click to toggle source
    keep_if → Enumerator

    Deletes every environment variable where the block evaluates to false.

    Returns an enumerator if no block was given.

     
                   static VALUE
    env_keep_if(VALUE ehash)
    {
        RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
        env_select_bang(ehash);
        return envtbl;
    }
                
    key(value) → name click to toggle source

    Returns the name of the environment variable with value. If the value is not found nil is returned.

     
                   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;
    }
                
    key?(name) → true or false click to toggle source

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

     
                   static VALUE
    env_has_key(VALUE env, VALUE key)
    {
        const char *s;
    
        s = env_name(key);
        if (getenv(s)) return Qtrue;
        return Qfalse;
    }
                
    keys → Array click to toggle source

    Returns every environment variable name in an Array

     
                   static VALUE
    env_keys(void)
    {
        char **env;
        VALUE ary;
    
        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));
            }
            env++;
        }
        FREE_ENVIRON(environ);
        return ary;
    }
                
    length click to toggle source

    Returns the number of environment variables.

     
                   static VALUE
    env_size(void)
    {
        int i;
        char **env;
    
        env = GET_ENVIRON(environ);
        for (i=0; env[i]; i++)
            ;
        FREE_ENVIRON(environ);
        return INT2FIX(i);
    }
                
    member?(name) → true or false click to toggle source

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

     
                   static VALUE
    env_has_key(VALUE env, VALUE key)
    {
        const char *s;
    
        s = env_name(key);
        if (getenv(s)) return Qtrue;
        return Qfalse;
    }
                
    rassoc(value) click to toggle source

    Returns an Array of the name and value of the environment variable with value or nil if the value cannot be found.

     
                   static VALUE
    env_rassoc(VALUE dmy, VALUE obj)
    {
        char **env;
    
        obj = rb_check_string_type(obj);
        if (NIL_P(obj)) return Qnil;
        rb_check_safe_obj(obj);
        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_tainted_str_new(*env, s-*env-1), obj);
                    FREE_ENVIRON(environ);
                    return result;
                }
            }
            env++;
        }
        FREE_ENVIRON(environ);
        return Qnil;
    }
                
    rehash click to toggle source

    Re-hashing the environment variables does nothing. It is provided for compatibility with Hash.

     
                   static VALUE
    env_none(void)
    {
        return Qnil;
    }
                
    reject { |name, value| } → Hash click to toggle source
    reject → Enumerator

    Same as ENV#delete_if, but works on (and returns) a copy of the environment.

     
                   static VALUE
    env_reject(void)
    {
        return rb_hash_delete_if(env_to_hash());
    }
                
    reject! { |name, value| } → ENV or nil click to toggle source
    reject! → Enumerator

    Equivalent to ENV#delete_if but returns nil if no changes were made.

    Returns an Enumerator if no block was given.

     
                   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();
        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))) {
                    FL_UNSET(RARRAY_AREF(keys, i), FL_TAINT);
                    env_delete(Qnil, RARRAY_AREF(keys, i));
                    del++;
                }
            }
        }
        RB_GC_GUARD(keys);
        if (del == 0) return Qnil;
        return envtbl;
    }
                
    replace(hash) → env click to toggle source

    Replaces the contents of the environment variables with the contents of hash.

     
                   static VALUE
    env_replace(VALUE env, VALUE hash)
    {
        VALUE keys;
        long i;
    
        keys = env_keys();
        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(env, RARRAY_AREF(keys, i));
        }
        RB_GC_GUARD(keys);
        return env;
    }
                
    select { |name, value| } → Hash click to toggle source
    select → Enumerator

    Returns a copy of the environment for entries where the block returns true.

    Returns an Enumerator if no block was given.

     
                   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();
        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;
    }
                
    select! { |name, value| } → ENV or nil click to toggle source
    select! → Enumerator

    Equivalent to ENV#keep_if but returns nil if no changes were made.

     
                   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();
        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))) {
                    FL_UNSET(RARRAY_AREF(keys, i), FL_TAINT);
                    env_delete(Qnil, RARRAY_AREF(keys, i));
                    del++;
                }
            }
        }
        RB_GC_GUARD(keys);
        if (del == 0) return Qnil;
        return envtbl;
    }
                
    shift → Array or nil click to toggle source

    Removes an environment variable name-value pair from ENV and returns it as an Array. Returns nil if when the environment is empty.

     
                   static VALUE
    env_shift(void)
    {
        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(Qnil, key);
                result = rb_assoc_new(key, val);
            }
        }
        FREE_ENVIRON(environ);
        return result;
    }
                
    size click to toggle source

    Returns the number of environment variables.

     
                   static VALUE
    env_size(void)
    {
        int i;
        char **env;
    
        env = GET_ENVIRON(environ);
        for (i=0; env[i]; i++)
            ;
        FREE_ENVIRON(environ);
        return INT2FIX(i);
    }
                
    store(name, value) → value click to toggle source

    Sets the environment variable name to value. If the value given is nil the environment variable is deleted. name must be a string.

     
                   static VALUE
    env_aset(VALUE obj, VALUE nm, VALUE val)
    {
        char *name, *value;
    
        if (NIL_P(val)) {
            env_delete(obj, nm);
            return Qnil;
        }
        SafeStringValue(nm);
        SafeStringValue(val);
        /* nm can be modified in `val.to_str`, don't get `name` before
         * check for `val` */
        get_env_ptr(name, nm);
        get_env_ptr(value, val);
    
        ruby_setenv(name, value);
        if (ENVMATCH(name, PATH_ENV)) {
            RB_GC_GUARD(nm);
            if (OBJ_TAINTED(val)) {
                /* already tainted, no check */
                path_tainted = 1;
                return val;
            }
            else {
                path_tainted_p(value);
            }
        }
        return val;
    }
                
    to_a → Array click to toggle source

    Converts the environment variables into an array of names and value arrays.

    ENV.to_a # => [["TERM", "xterm-color"], ["SHELL", "/bin/bash"], ...]
    
     
                   static VALUE
    env_to_a(void)
    {
        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;
    }
                
    to_hash → hash click to toggle source
    to_h → hash

    Creates a hash with a copy of the environment variables.

     
                   static VALUE
    env_to_hash(void)
    {
        char **env;
        VALUE hash;
    
        hash = rb_hash_new();
        env = GET_ENVIRON(environ);
        while (*env) {
            char *s = strchr(*env, '=');
            if (s) {
                rb_hash_aset(hash, env_str_new(*env, s-*env),
                                   env_str_new2(s+1));
            }
            env++;
        }
        FREE_ENVIRON(environ);
        return hash;
    }
                
    to_hash → hash click to toggle source

    Creates a hash with a copy of the environment variables.

     
                   static VALUE
    env_to_hash(void)
    {
        char **env;
        VALUE hash;
    
        hash = rb_hash_new();
        env = GET_ENVIRON(environ);
        while (*env) {
            char *s = strchr(*env, '=');
            if (s) {
                rb_hash_aset(hash, env_str_new(*env, s-*env),
                                   env_str_new2(s+1));
            }
            env++;
        }
        FREE_ENVIRON(environ);
        return hash;
    }
                
    to_s → "ENV" click to toggle source

    Returns “ENV”

     
                   static VALUE
    env_to_s(void)
    {
        return rb_usascii_str_new2("ENV");
    }
                
    update(hash) → Hash click to toggle source
    update(hash) { |name, old_value, new_value| } → Hash

    Adds the contents of hash to the environment variables. If no block is specified entries with duplicate keys are overwritten, otherwise the value of each duplicate name is determined by calling the block with the key, its value from the environment and its value from the hash.

     
                   static VALUE
    env_update(VALUE env, VALUE hash)
    {
        if (env == hash) return env;
        hash = to_hash(hash);
        rb_hash_foreach(hash, env_update_i, 0);
        return env;
    }
                
    value?(value) → true or false click to toggle source

    Returns true if there is an environment variable with the given value.

     
                   static VALUE
    env_has_value(VALUE dmy, VALUE obj)
    {
        char **env;
    
        obj = rb_check_string_type(obj);
        if (NIL_P(obj)) return Qnil;
        rb_check_safe_obj(obj);
        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;
    }
                
    values → Array click to toggle source

    Returns every environment variable value as an Array

     
                   static VALUE
    env_values(void)
    {
        VALUE ary;
        char **env;
    
        ary = rb_ary_new();
        env = GET_ENVIRON(environ);
        while (*env) {
            char *s = strchr(*env, '=');
            if (s) {
                rb_ary_push(ary, env_str_new2(s+1));
            }
            env++;
        }
        FREE_ENVIRON(environ);
        return ary;
    }
                
    values_at(name, ...) → Array click to toggle source

    Returns an array containing the environment variable values associated with the given names. See also ::select.

     
                   static VALUE
    env_values_at(int argc, VALUE *argv)
    {
        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;
    }