![]() Returns the string resulting from applying format_string to anyĪdditional arguments. exec "echo *" # echoes list of files in current directory # never get here exec "echo", "*" # echoes an asterisk # never get here The modified attributes may be retained when exec(2) systemįor example, hard resource limits are not restorable.Ĭonsider to create a child process using ::spawn or #system if this is not acceptable. See ::spawnįor more details about the given options. This method modifies process attributes according to given If the command fails to execute (typically Errno::ENOENT when This behavior is modified by the given env and Of the original program (including open file descriptors). In order to execute the command, one of the exec(2) systemĬalls are used, so the running command may inherit some of the environment )), starting a two-element array at theīeginning of the command, the first element is the command to be executed,Īnd the second argument is used as the argv value, which )), the first is taken as a command name and the rest are passedĪs parameters to command with no shell expansion. In the second form ( exec("command1", "arg1", Spawn() and IO#pid for IO.popen) is the pid of the invoked Note that this behavior is observable by pid obtained (return value of You can force shell invocation by adding “ ” to the string (because “ ” is Ruby invokes the command directly without shell No shell reserved word and no special built-in If the string from the first form ( exec("command")) Unix-like systems, same as ENV (orĮNV on Windows NT series), and similar. The standard shell always means "/bin/sh" on In the first form, the string is taken as a command line that is subject to ![]() )Ĭommand name, argv and zero or more arguments (no shell) )Ĭommand name and one or more arguments (no shell) exec(, arg1. Replaces the current process by running the given externalĬommand, which can take one of the following forms: exec(commandline)Ĭommand line string which is passed to the standard shell exec(cmdname, arg1. If f = nil puts "in Child" exit else puts "Got: #" else # child process puts "in Child" end end Open a subprocess running the same Ruby program: f = open( "|-", "w+") Open a subprocess and read its output: cmd = open( "|date") Reading from “testfile”: open( "testfile") do | f | print f. Subprocess will be terminated at the end of the block. Object will be connected to the child's $stdin and $stdout. The block parameter will be an IO object in the With the open call, that block will run twice - once in the parent and once When the subprocess is ruby (opened via "|-"), the ( "|-"), Ruby forks, and this subprocess is connected If the command following the pipe is a single minus sign May be used to write to the standard input and read from the standard ( "|"), a subprocess is created, connected to theĬaller by a pair of pipes. If a block is specified, it will be invoked with the IO object as a parameter, and the IO will be automatically closed when the block See File.new and the open(2) and chmod(2) man ![]() ![]() If a file is being created, its initial permissions may be set using the If it is a string, it is either “fmode”, “fmode:ext_enc”, orĭocumentation of the mode string directives. Integer, it must be bitwise-or of open(2) flags, such as File::RDWR orįile::EXCL. The mode is either a string or an integer. Treat it as the name of a file to open using the specified mode (defaulting If path does not start with a pipe character ( |), ![]() These methods are called without a receiver and thus canīe called in functional form: sprintf "%.1f", 1.234 #=> "1.2" Public Class MethodsĬreates an IO object connected to the given stream, The Kernel instance methods are documented inĬlass Object while the module methods areĭocumented here. The Kernel module is included by class Object, so its methods are available in every Ruby See the documentation of these methods for Allow activation of specific gem versions and overrides the require method on Kernel to make gems appear as if they live on the ![]()
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