Results for: "Pathname"

A Zlib::Deflate.deflate wrapper

A Zlib::Inflate#inflate wrapper

Set array of platforms this RubyGems supports (primarily for testing).

Array of platforms this RubyGems supports.

Prints the amount of time the supplied block takes to run using the debug UI output.

Returns the currenctly set formatter. By default, it is set to DidYouMean::Formatter.

Updates the primary formatter used to format the suggestions.

Get the thread of the primary server.

This returns nil if there is no primary server. See primary_server.

Get the thread of the primary server.

This returns nil if there is no primary server. See primary_server.

Returns true if new is newer than all old_list. Non-existent files are older than any file.

FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \
    system 'make hello.o'

Returns true if new is newer than all old_list. Non-existent files are older than any file.

FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \
    system 'make hello.o'
No documentation available
No documentation available

Synopsis

URI::parse(uri_str)

Args

uri_str

String with URI.

Description

Creates one of the URI’s subclasses instance from the string.

Raises

URI::InvalidURIError

Raised if URI given is not a correct one.

Usage

require 'uri'

uri = URI.parse("http://www.ruby-lang.org/")
# => #<URI::HTTP http://www.ruby-lang.org/>
uri.scheme
# => "http"
uri.host
# => "www.ruby-lang.org"

It’s recommended to first ::escape the provided uri_str if there are any invalid URI characters.

Perform an operation in a block, raising an error if it takes longer than sec seconds to complete.

sec

Number of seconds to wait for the block to terminate. Any number may be used, including Floats to specify fractional seconds. A value of 0 or nil will execute the block without any timeout.

klass

Exception Class to raise if the block fails to terminate in sec seconds. Omitting will use the default, Timeout::Error

message

Error message to raise with Exception Class. Omitting will use the default, “execution expired”

Returns the result of the block if the block completed before sec seconds, otherwise throws an exception, based on the value of klass.

The exception thrown to terminate the given block cannot be rescued inside the block unless klass is given explicitly. However, the block can use ensure to prevent the handling of the exception. For that reason, this method cannot be relied on to enforce timeouts for untrusted blocks.

Note that this is both a method of module Timeout, so you can include Timeout into your classes so they have a timeout method, as well as a module method, so you can call it directly as Timeout.timeout().

Perform an operation in a block, raising an error if it takes longer than sec seconds to complete.

sec

Number of seconds to wait for the block to terminate. Any number may be used, including Floats to specify fractional seconds. A value of 0 or nil will execute the block without any timeout.

klass

Exception Class to raise if the block fails to terminate in sec seconds. Omitting will use the default, Timeout::Error

message

Error message to raise with Exception Class. Omitting will use the default, “execution expired”

Returns the result of the block if the block completed before sec seconds, otherwise throws an exception, based on the value of klass.

The exception thrown to terminate the given block cannot be rescued inside the block unless klass is given explicitly. However, the block can use ensure to prevent the handling of the exception. For that reason, this method cannot be relied on to enforce timeouts for untrusted blocks.

Note that this is both a method of module Timeout, so you can include Timeout into your classes so they have a timeout method, as well as a module method, so you can call it directly as Timeout.timeout().

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]

spawn executes specified command and return its pid.

pid = spawn("tar xf ruby-2.0.0-p195.tar.bz2")
Process.wait pid

pid = spawn(RbConfig.ruby, "-eputs'Hello, world!'")
Process.wait pid

This method is similar to Kernel#system but it doesn’t wait for the command to finish.

The parent process should use Process.wait to collect the termination status of its child or use Process.detach to register disinterest in their status; otherwise, the operating system may accumulate zombie processes.

spawn has bunch of options to specify process attributes:

env: hash
  name => val : set the environment variable
  name => nil : unset the environment variable

  the keys and the values except for +nil+ must be strings.
command...:
  commandline                 : command line string which is passed to the standard shell
  cmdname, arg1, ...          : command name and one or more arguments (This form does not use the shell. See below for caveats.)
  [cmdname, argv0], arg1, ... : command name, argv[0] and zero or more arguments (no shell)
options: hash
  clearing environment variables:
    :unsetenv_others => true   : clear environment variables except specified by env
    :unsetenv_others => false  : don't clear (default)
  process group:
    :pgroup => true or 0 : make a new process group
    :pgroup => pgid      : join the specified process group
    :pgroup => nil       : don't change the process group (default)
  create new process group: Windows only
    :new_pgroup => true  : the new process is the root process of a new process group
    :new_pgroup => false : don't create a new process group (default)
  resource limit: resourcename is core, cpu, data, etc.  See Process.setrlimit.
    :rlimit_resourcename => limit
    :rlimit_resourcename => [cur_limit, max_limit]
  umask:
    :umask => int
  redirection:
    key:
      FD              : single file descriptor in child process
      [FD, FD, ...]   : multiple file descriptor in child process
    value:
      FD                        : redirect to the file descriptor in parent process
      string                    : redirect to file with open(string, "r" or "w")
      [string]                  : redirect to file with open(string, File::RDONLY)
      [string, open_mode]       : redirect to file with open(string, open_mode, 0644)
      [string, open_mode, perm] : redirect to file with open(string, open_mode, perm)
      [:child, FD]              : redirect to the redirected file descriptor
      :close                    : close the file descriptor in child process
    FD is one of follows
      :in     : the file descriptor 0 which is the standard input
      :out    : the file descriptor 1 which is the standard output
      :err    : the file descriptor 2 which is the standard error
      integer : the file descriptor of specified the integer
      io      : the file descriptor specified as io.fileno
  file descriptor inheritance: close non-redirected non-standard fds (3, 4, 5, ...) or not
    :close_others => false  : inherit
  current directory:
    :chdir => str

The cmdname, arg1, ... form does not use the shell. However, on different OSes, different things are provided as built-in commands. An example of this is +‘echo’+, which is a built-in on Windows, but is a normal program on Linux and Mac OS X. This means that Process.spawn 'echo', '%Path%' will display the contents of the %Path% environment variable on Windows, but Process.spawn 'echo', '$PATH' prints the literal $PATH.

If a hash is given as env, the environment is updated by env before exec(2) in the child process. If a pair in env has nil as the value, the variable is deleted.

# set FOO as BAR and unset BAZ.
pid = spawn({"FOO"=>"BAR", "BAZ"=>nil}, command)

If a hash is given as options, it specifies process group, create new process group, resource limit, current directory, umask and redirects for the child process. Also, it can be specified to clear environment variables.

The :unsetenv_others key in options specifies to clear environment variables, other than specified by env.

pid = spawn(command, :unsetenv_others=>true) # no environment variable
pid = spawn({"FOO"=>"BAR"}, command, :unsetenv_others=>true) # FOO only

The :pgroup key in options specifies a process group. The corresponding value should be true, zero, a positive integer, or nil. true and zero cause the process to be a process leader of a new process group. A non-zero positive integer causes the process to join the provided process group. The default value, nil, causes the process to remain in the same process group.

pid = spawn(command, :pgroup=>true) # process leader
pid = spawn(command, :pgroup=>10) # belongs to the process group 10

The :new_pgroup key in options specifies to pass CREATE_NEW_PROCESS_GROUP flag to CreateProcessW() that is Windows API. This option is only for Windows. true means the new process is the root process of the new process group. The new process has CTRL+C disabled. This flag is necessary for Process.kill(:SIGINT, pid) on the subprocess. :new_pgroup is false by default.

pid = spawn(command, :new_pgroup=>true)  # new process group
pid = spawn(command, :new_pgroup=>false) # same process group

The :rlimit_foo key specifies a resource limit. foo should be one of resource types such as core. The corresponding value should be an integer or an array which have one or two integers: same as cur_limit and max_limit arguments for Process.setrlimit.

cur, max = Process.getrlimit(:CORE)
pid = spawn(command, :rlimit_core=>[0,max]) # disable core temporary.
pid = spawn(command, :rlimit_core=>max) # enable core dump
pid = spawn(command, :rlimit_core=>0) # never dump core.

The :umask key in options specifies the umask.

pid = spawn(command, :umask=>077)

The :in, :out, :err, an integer, an IO and an array key specifies a redirection. The redirection maps a file descriptor in the child process.

For example, stderr can be merged into stdout as follows:

pid = spawn(command, :err=>:out)
pid = spawn(command, 2=>1)
pid = spawn(command, STDERR=>:out)
pid = spawn(command, STDERR=>STDOUT)

The hash keys specifies a file descriptor in the child process started by spawn. :err, 2 and STDERR specifies the standard error stream (stderr).

The hash values specifies a file descriptor in the parent process which invokes spawn. :out, 1 and STDOUT specifies the standard output stream (stdout).

In the above example, the standard output in the child process is not specified. So it is inherited from the parent process.

The standard input stream (stdin) can be specified by :in, 0 and STDIN.

A filename can be specified as a hash value.

pid = spawn(command, :in=>"/dev/null") # read mode
pid = spawn(command, :out=>"/dev/null") # write mode
pid = spawn(command, :err=>"log") # write mode
pid = spawn(command, [:out, :err]=>"/dev/null") # write mode
pid = spawn(command, 3=>"/dev/null") # read mode

For stdout and stderr (and combination of them), it is opened in write mode. Otherwise read mode is used.

For specifying flags and permission of file creation explicitly, an array is used instead.

pid = spawn(command, :in=>["file"]) # read mode is assumed
pid = spawn(command, :in=>["file", "r"])
pid = spawn(command, :out=>["log", "w"]) # 0644 assumed
pid = spawn(command, :out=>["log", "w", 0600])
pid = spawn(command, :out=>["log", File::WRONLY|File::EXCL|File::CREAT, 0600])

The array specifies a filename, flags and permission. The flags can be a string or an integer. If the flags is omitted or nil, File::RDONLY is assumed. The permission should be an integer. If the permission is omitted or nil, 0644 is assumed.

If an array of IOs and integers are specified as a hash key, all the elements are redirected.

# stdout and stderr is redirected to log file.
# The file "log" is opened just once.
pid = spawn(command, [:out, :err]=>["log", "w"])

Another way to merge multiple file descriptors is [:child, fd]. [:child, fd] means the file descriptor in the child process. This is different from fd. For example, :err=>:out means redirecting child stderr to parent stdout. But :err=>[:child, :out] means redirecting child stderr to child stdout. They differ if stdout is redirected in the child process as follows.

# stdout and stderr is redirected to log file.
# The file "log" is opened just once.
pid = spawn(command, :out=>["log", "w"], :err=>[:child, :out])

[:child, :out] can be used to merge stderr into stdout in IO.popen. In this case, IO.popen redirects stdout to a pipe in the child process and [:child, :out] refers the redirected stdout.

io = IO.popen(["sh", "-c", "echo out; echo err >&2", :err=>[:child, :out]])
p io.read #=> "out\nerr\n"

The :chdir key in options specifies the current directory.

pid = spawn(command, :chdir=>"/var/tmp")

spawn closes all non-standard unspecified descriptors by default. The “standard” descriptors are 0, 1 and 2. This behavior is specified by :close_others option. :close_others doesn’t affect the standard descriptors which are closed only if :close is specified explicitly.

pid = spawn(command, :close_others=>true)  # close 3,4,5,... (default)
pid = spawn(command, :close_others=>false) # don't close 3,4,5,...

:close_others is false by default for spawn and IO.popen.

Note that fds which close-on-exec flag is already set are closed regardless of :close_others option.

So IO.pipe and spawn can be used as IO.popen.

# similar to r = IO.popen(command)
r, w = IO.pipe
pid = spawn(command, :out=>w)   # r, w is closed in the child process.
w.close

:close is specified as a hash value to close a fd individually.

f = open(foo)
system(command, f=>:close)        # don't inherit f.

If a file descriptor need to be inherited, io=>io can be used.

# valgrind has --log-fd option for log destination.
# log_w=>log_w indicates log_w.fileno inherits to child process.
log_r, log_w = IO.pipe
pid = spawn("valgrind", "--log-fd=#{log_w.fileno}", "echo", "a", log_w=>log_w)
log_w.close
p log_r.read

It is also possible to exchange file descriptors.

pid = spawn(command, :out=>:err, :err=>:out)

The hash keys specify file descriptors in the child process. The hash values specifies file descriptors in the parent process. So the above specifies exchanging stdout and stderr. Internally, spawn uses an extra file descriptor to resolve such cyclic file descriptor mapping.

See Kernel.exec for the standard shell.

Returns a Tms structure (see Process::Tms) that contains user and system CPU times for this process, and also for children processes.

t = Process.times
[ t.utime, t.stime, t.cutime, t.cstime ]   #=> [0.0, 0.02, 0.00, 0.00]

(see Gem::Resolver::Molinillo::ResolutionState#name)

No documentation available
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