Changes permission bits on the named files (in list
) to the bit pattern represented by mode
.
FileUtils.chmod_R 0700, "/tmp/app.#{$$}" FileUtils.chmod_R "u=wrx", "/tmp/app.#{$$}"
Changes permission bits on the named files (in list
) to the bit pattern represented by mode
.
FileUtils.chmod_R 0700, "/tmp/app.#{$$}" FileUtils.chmod_R "u=wrx", "/tmp/app.#{$$}"
Changes owner and group on the named files (in list
) to the user user
and the group group
. user
and group
may be an ID (Integer/String) or a name (String). If user
or group
is nil, this method does not change the attribute.
FileUtils.chown 'root', 'staff', '/usr/local/bin/ruby' FileUtils.chown nil, 'bin', Dir.glob('/usr/bin/*'), :verbose => true
Changes owner and group on the named files (in list
) to the user user
and the group group
. user
and group
may be an ID (Integer/String) or a name (String). If user
or group
is nil, this method does not change the attribute.
FileUtils.chown 'root', 'staff', '/usr/local/bin/ruby' FileUtils.chown nil, 'bin', Dir.glob('/usr/bin/*'), :verbose => true
Changes owner and group on the named files (in list
) to the user user
and the group group
recursively. user
and group
may be an ID (Integer/String) or a name (String). If user
or group
is nil, this method does not change the attribute.
FileUtils.chown_R 'www', 'www', '/var/www/htdocs' FileUtils.chown_R 'cvs', 'cvs', '/var/cvs', :verbose => true
Changes owner and group on the named files (in list
) to the user user
and the group group
recursively. user
and group
may be an ID (Integer/String) or a name (String). If user
or group
is nil, this method does not change the attribute.
FileUtils.chown_R 'www', 'www', '/var/www/htdocs' FileUtils.chown_R 'cvs', 'cvs', '/var/cvs', :verbose => true
Updates modification time (mtime) and access time (atime) of file(s) in list
. Files are created if they don’t exist.
FileUtils.touch 'timestamp' FileUtils.touch Dir.glob('*.c'); system 'make'
Updates modification time (mtime) and access time (atime) of file(s) in list
. Files are created if they don’t exist.
FileUtils.touch 'timestamp' FileUtils.touch Dir.glob('*.c'); system 'make'
Returns an Array of method names which have any options.
p FileUtils.commands #=> ["chmod", "cp", "cp_r", "install", ...]
Computes the arc tangent given y
and x
. Returns a Float
in the range -PI..PI. Return value is a angle in radians between the positive x-axis of cartesian plane and the point given by the coordinates (x
, y
) on it.
Domain: (-INFINITY, INFINITY)
Codomain: [-PI, PI]
Math.atan2(-0.0, -1.0) #=> -3.141592653589793 Math.atan2(-1.0, -1.0) #=> -2.356194490192345 Math.atan2(-1.0, 0.0) #=> -1.5707963267948966 Math.atan2(-1.0, 1.0) #=> -0.7853981633974483 Math.atan2(-0.0, 1.0) #=> -0.0 Math.atan2(0.0, 1.0) #=> 0.0 Math.atan2(1.0, 1.0) #=> 0.7853981633974483 Math.atan2(1.0, 0.0) #=> 1.5707963267948966 Math.atan2(1.0, -1.0) #=> 2.356194490192345 Math.atan2(0.0, -1.0) #=> 3.141592653589793 Math.atan2(INFINITY, INFINITY) #=> 0.7853981633974483 Math.atan2(INFINITY, -INFINITY) #=> 2.356194490192345 Math.atan2(-INFINITY, INFINITY) #=> -0.7853981633974483 Math.atan2(-INFINITY, -INFINITY) #=> -2.356194490192345
Computes the arc tangent of x
. Returns -PI/2..PI/2.
Domain: (-INFINITY, INFINITY)
Codomain: (-PI/2, PI/2)
Math.atan(0) #=> 0.0
Computes the inverse hyperbolic tangent of x
.
Domain: (-1, 1)
Codomain: (-INFINITY, INFINITY)
Math.atanh(1) #=> Infinity
Calculates the gamma function of x.
Note that gamma(n) is same as fact(n-1) for integer n > 0. However gamma(n) returns float and can be an approximation.
def fact(n) (1..n).inject(1) {|r,i| r*i } end 1.upto(26) {|i| p [i, Math.gamma(i), fact(i-1)] } #=> [1, 1.0, 1] # [2, 1.0, 1] # [3, 2.0, 2] # [4, 6.0, 6] # [5, 24.0, 24] # [6, 120.0, 120] # [7, 720.0, 720] # [8, 5040.0, 5040] # [9, 40320.0, 40320] # [10, 362880.0, 362880] # [11, 3628800.0, 3628800] # [12, 39916800.0, 39916800] # [13, 479001600.0, 479001600] # [14, 6227020800.0, 6227020800] # [15, 87178291200.0, 87178291200] # [16, 1307674368000.0, 1307674368000] # [17, 20922789888000.0, 20922789888000] # [18, 355687428096000.0, 355687428096000] # [19, 6.402373705728e+15, 6402373705728000] # [20, 1.21645100408832e+17, 121645100408832000] # [21, 2.43290200817664e+18, 2432902008176640000] # [22, 5.109094217170944e+19, 51090942171709440000] # [23, 1.1240007277776077e+21, 1124000727777607680000] # [24, 2.5852016738885062e+22, 25852016738884976640000] # [25, 6.204484017332391e+23, 620448401733239439360000] # [26, 1.5511210043330954e+25, 15511210043330985984000000]
Calculates the logarithmic gamma of x
and the sign of gamma of x
.
Math.lgamma(x)
is same as
[Math.log(Math.gamma(x).abs), Math.gamma(x) < 0 ? -1 : 1]
but avoid overflow by Math.gamma(x)
for large x.
Math.lgamma(0) #=> [Infinity, 1]
Set
the changed state of this object. Notifications will be sent only if the changed state
is true
.
state
Boolean indicating the changed state of this Observable
.
Returns true if this object’s state has been changed since the last notify_observers
call.
The standard configuration object for gems.
Use the given configuration object (which implements the ConfigFile
protocol) as the standard configuration object.
The path to the data directory specified by the gem name. If the package is not available as a gem, return nil.
A Zlib::Deflate.deflate
wrapper
Retrieve the PathSupport
object that RubyGems uses to lookup files.
Initialize the filesystem paths to use from env
. env
is a hash-like object (typically ENV
) that is queried for ‘GEM_HOME’, ‘GEM_PATH’, and ‘GEM_SPEC_CACHE’ Keys for the env
hash should be Strings, and values of the hash should be Strings or nil
.