Returns system temporary directory; typically “/tmp”.
Returns system configuration variable using confstr().
name should be a constant under Etc
which begins with CS_
.
The return value is a string or nil. nil means no configuration-defined value. (confstr() returns 0 but errno is not set.)
Etc.confstr(Etc::CS_PATH) #=> "/bin:/usr/bin" # GNU/Linux Etc.confstr(Etc::CS_GNU_LIBC_VERSION) #=> "glibc 2.18" Etc.confstr(Etc::CS_GNU_LIBPTHREAD_VERSION) #=> "NPTL 2.18"
Returns the number of online processors.
The result is intended as the number of processes to use all available processors.
This method is implemented using:
sched_getaffinity(): Linux
sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
Example:
require 'etc' p Etc.nprocessors #=> 4
The result might be smaller number than physical cpus especially when ruby process is bound to specific cpus. This is intended for getting better parallel processing.
Example: (Linux)
linux$ taskset 0x3 ./ruby -retc -e "p Etc.nprocessors" #=> 2
Change the size of the memory allocated at the memory location addr
to size
bytes. Returns the memory address of the reallocated memory, which may be different than the address passed in.
Free the memory at address addr
Convert str
to ISO-2022-JP
Convert str
to ISO-2022-JP
Convert str
to EUC-JP
Convert str
to EUC-JP
Convert str
to Shift_JIS
Convert str
to Shift_JIS
Convert str
to UTF-8
Convert str
to UTF-8
Convert str
to UTF-16
Convert str
to UTF-16
Convert str
to UTF-32
Convert str
to UTF-32
Convert self
to locale encoding
Convert self
to locale encoding
Returns a Digest
subclass by name
require 'openssl' OpenSSL::Digest("MD5") # => OpenSSL::Digest::MD5 Digest("Foo") # => NameError: wrong constant name Foo
Returns a Digest
subclass by name
require 'openssl' OpenSSL::Digest("MD5") # => OpenSSL::Digest::MD5 Digest("Foo") # => NameError: wrong constant name Foo
See any remaining errors held in queue.
Any errors you see here are probably due to a bug in Ruby’s OpenSSL
implementation.
Shows the prompt
and reads the inputted line with line editing. The inputted line is added to the history if add_hist
is true.
Returns nil when the inputted line is empty and user inputs EOF (Presses ^D on UNIX).
Raises IOError
exception if one of below conditions are satisfied.
stdin was closed.
stdout was closed.
This method supports thread. Switches the thread context when waits inputting line.
Supports line edit when inputs line. Provides VI and Emacs editing mode. Default is Emacs editing mode.
NOTE: Terminates ruby interpreter and does not return the terminal status after user pressed ‘^C’ when wait inputting line. Give 3 examples that avoid it.
Catches the Interrupt
exception by pressed ^C after returns terminal status:
require "readline" stty_save = `stty -g`.chomp begin while buf = Readline.readline p buf end rescue Interrupt system("stty", stty_save) exit end end end
Catches the INT signal by pressed ^C after returns terminal status:
require "readline" stty_save = `stty -g`.chomp trap("INT") { system "stty", stty_save; exit } while buf = Readline.readline p buf end
Ignores pressing ^C:
require "readline" trap("INT", "SIG_IGN") while buf = Readline.readline p buf end
Can make as follows with Readline::HISTORY
constant. It does not record to the history if the inputted line is empty or the same it as last one.
require "readline" while buf = Readline.readline("> ", true) # p Readline::HISTORY.to_a Readline::HISTORY.pop if /^\s*$/ =~ buf begin if Readline::HISTORY[Readline::HISTORY.length-2] == buf Readline::HISTORY.pop end rescue IndexError end # p Readline::HISTORY.to_a print "-> ", buf, "\n" end
Change what’s displayed on the screen to reflect the current contents.
See GNU Readline’s rl_redisplay function.
Raises NotImplementedError
if the using readline library does not support.