Returns true if the named file is writable by the effective user and group id of this process. See eaccess(3).
Returns true if the named file is executable by the effective user and group id of this process. See eaccess(3).
Returns true if the named files are identical.
file_1 and file_2 can be an IO object.
open("a", "w") {} p File.identical?("a", "a") #=> true p File.identical?("a", "./a") #=> true File.link("a", "b") p File.identical?("a", "b") #=> true File.symlink("a", "c") p File.identical?("a", "c") #=> true open("d", "w") {} p File.identical?("a", "d") #=> false
Returns the hash of available encoding alias and original encoding name.
Encoding.aliases
#=> {"BINARY"=>"ASCII-8BIT", "ASCII"=>"US-ASCII", "ANSI_X3.4-1986"=>"US-ASCII",
"SJIS"=>"Shift_JIS", "eucJP"=>"EUC-JP", "CP932"=>"Windows-31J"}
Return the status value associated with this system exit.
In the first form, returns an array of the names of all constants accessible from the point of call. This list includes the names of all modules and classes defined in the global scope.
Module.constants.first(4) # => [:ARGF, :ARGV, :ArgumentError, :Array] Module.constants.include?(:SEEK_SET) # => false class IO Module.constants.include?(:SEEK_SET) # => true end
The second form calls the instance method constants.
Returns an array of the names of the constants accessible in mod. This includes the names of constants in any included modules (example at start of section), unless the inherit parameter is set to false.
The implementation makes no guarantees about the order in which the constants are yielded.
IO.constants.include?(:SYNC) #=> true IO.constants(false).include?(:SYNC) #=> false
Also see Module::const_defined?.
Returns a simpler approximation of the value if the optional argument eps is given (rat-|eps| <= result <= rat+|eps|), self otherwise.
r = Rational(5033165, 16777216) r.rationalize #=> (5033165/16777216) r.rationalize(Rational('0.01')) #=> (3/10) r.rationalize(Rational('0.1')) #=> (1/3)
Creates a date object denoting the given ordinal date.
The day of year should be a negative or a positive number (as a relative day from the end of year when negative). It should not be zero.
Date.ordinal(2001) #=> #<Date: 2001-01-01 ...> Date.ordinal(2001,34) #=> #<Date: 2001-02-03 ...> Date.ordinal(2001,-1) #=> #<Date: 2001-12-31 ...>
Creates a date object denoting the given week date.
The week and the day of week should be a negative or a positive number (as a relative week/day from the end of year/week when negative). They should not be zero.
Date.commercial(2001) #=> #<Date: 2001-01-01 ...> Date.commercial(2002) #=> #<Date: 2001-12-31 ...> Date.commercial(2001,5,6) #=> #<Date: 2001-02-03 ...>
Returns the Julian day number denoting the day of calendar reform.
Date.new(2001,2,3).start #=> 2299161.0 Date.new(2001,2,3,Date::GREGORIAN).start #=> -Infinity
Creates a DateTime object denoting the given ordinal date.
DateTime.ordinal(2001,34) #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...> DateTime.ordinal(2001,34,4,5,6,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...> DateTime.ordinal(2001,-332,-20,-55,-54,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
Creates a DateTime object denoting the given week date.
DateTime.commercial(2001) #=> #<DateTime: 2001-01-01T00:00:00+00:00 ...> DateTime.commercial(2002) #=> #<DateTime: 2001-12-31T00:00:00+00:00 ...> DateTime.commercial(2001,5,6,4,5,6,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
Same as Time::gm, but interprets the values in the local time zone.
Time.local(2000,"jan",1,20,15,1) #=> 2000-01-01 20:15:01 -0600
Converts time to local time (using the local time zone in effect at the creation time of time) modifying the receiver.
If utc_offset is given, it is used instead of the local time.
t = Time.utc(2000, "jan", 1, 20, 15, 1) #=> 2000-01-01 20:15:01 UTC t.utc? #=> true t.localtime #=> 2000-01-01 14:15:01 -0600 t.utc? #=> false t.localtime("+09:00") #=> 2000-01-02 05:15:01 +0900 t.utc? #=> false
If utc_offset is not given and time is local time, just returns the receiver.
Returns a new Time object representing time in local time (using the local time zone in effect for this process).
If utc_offset is given, it is used instead of the local time. utc_offset can be given as a human-readable string (eg. "+09:00") or as a number of seconds (eg. 32400).
t = Time.utc(2000,1,1,20,15,1) #=> 2000-01-01 20:15:01 UTC t.utc? #=> true l = t.getlocal #=> 2000-01-01 14:15:01 -0600 l.utc? #=> false t == l #=> true j = t.getlocal("+09:00") #=> 2000-01-02 05:15:01 +0900 j.utc? #=> false t == j #=> true k = t.getlocal(9*60*60) #=> 2000-01-02 05:15:01 +0900 k.utc? #=> false t == k #=> true
Returns an array of all the string values in the database.
Returns true if the database contains the specified string value, false otherwise.
Returns the values for this struct as an Array.
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.to_a[1] #=> "123 Maple, Anytown NC"
Returns status information for ios as an object of type File::Stat.
f = File.new("testfile") s = f.stat "%o" % s.mode #=> "100644" s.blksize #=> 4096 s.atime #=> Wed Apr 09 08:53:54 CDT 2003
Immediately writes all buffered data in ios to disk.
If the underlying operating system does not support fdatasync(2), IO#fsync is called instead (which might raise a NotImplementedError).
Reads at most maxlen bytes from the I/O stream. It blocks only if ios has no data immediately available. It doesn’t block if some data available.
If the optional outbuf argument is present, it must reference a String, which will receive the data. The outbuf will contain only the received data after the method call even if it is not empty at the beginning.
It raises EOFError on end of file.
readpartial is designed for streams such as pipe, socket, tty, etc. It blocks only when no data immediately available. This means that it blocks only when following all conditions hold.
the byte buffer in the IO object is empty.
the content of the stream is empty.
the stream is not reached to EOF.
When readpartial blocks, it waits data or EOF on the stream. If some data is reached, readpartial returns with the data. If EOF is reached, readpartial raises EOFError.
When readpartial doesn’t blocks, it returns or raises immediately. If the byte buffer is not empty, it returns the data in the buffer. Otherwise if the stream has some content, it returns the data in the stream. Otherwise if the stream is reached to EOF, it raises EOFError.
r, w = IO.pipe # buffer pipe content w << "abc" # "" "abc". r.readpartial(4096) #=> "abc" "" "" r.readpartial(4096) # blocks because buffer and pipe is empty. r, w = IO.pipe # buffer pipe content w << "abc" # "" "abc" w.close # "" "abc" EOF r.readpartial(4096) #=> "abc" "" EOF r.readpartial(4096) # raises EOFError r, w = IO.pipe # buffer pipe content w << "abc\ndef\n" # "" "abc\ndef\n" r.gets #=> "abc\n" "def\n" "" w << "ghi\n" # "def\n" "ghi\n" r.readpartial(4096) #=> "def\n" "" "ghi\n" r.readpartial(4096) #=> "ghi\n" "" ""
Note that readpartial behaves similar to sysread. The differences are:
If the byte buffer is not empty, read from the byte buffer instead of “sysread for buffered IO (IOError)”.
It doesn’t cause Errno::EWOULDBLOCK and Errno::EINTR. When readpartial meets EWOULDBLOCK and EINTR by read system call, readpartial retry the system call.
The latter means that readpartial is nonblocking-flag insensitive. It blocks on the situation IO#sysread causes Errno::EWOULDBLOCK as if the fd is blocking mode.
Returns the current offset (in bytes) of ios.
f = File.new("testfile") f.pos #=> 0 f.gets #=> "This is line one\n" f.pos #=> 17
Returns an array of all values of this database.