Changes permissions on the entries at the paths given in list (a single path or an array of paths) to the permissions given by mode; returns list if it is an array, [list] otherwise:
Modifies each entry that is a regular file using File.chmod.
Modifies each entry that is a symbolic link using File.lchmod.
Argument list or its elements should be interpretable as paths.
Argument mode may be either an integer or a string:
Integer mode: represents the permission bits to be set:
FileUtils.chmod(0755, 'src0.txt') FileUtils.chmod(0644, ['src0.txt', 'src0.dat'])
String mode: represents the permissions to be set:
The string is of the form [targets][[operator][perms[,perms]], where:
targets may be any combination of these letters:
'u': permissions apply to the file’s owner.
'g': permissions apply to users in the file’s group.
'o': permissions apply to other users not in the file’s group.
'a' (the default): permissions apply to all users.
operator may be one of these letters:
'+': adds permissions.
'-': removes permissions.
'=': sets (replaces) permissions.
perms (may be repeated, with separating commas) may be any combination of these letters:
'r': Read.
'w': Write.
'x': Execute (search, for a directory).
'X': Search (for a directories only; must be used with '+')
's': Uid or gid.
't': Sticky bit.
Examples:
FileUtils.chmod('u=wrx,go=rx', 'src1.txt') FileUtils.chmod('u=wrx,go=rx', '/usr/bin/ruby')
Keyword arguments:
noop: true - does not change permissions; returns nil.
verbose: true - prints an equivalent command:
FileUtils.chmod(0755, 'src0.txt', noop: true, verbose: true) FileUtils.chmod(0644, ['src0.txt', 'src0.dat'], noop: true, verbose: true) FileUtils.chmod('u=wrx,go=rx', 'src1.txt', noop: true, verbose: true) FileUtils.chmod('u=wrx,go=rx', '/usr/bin/ruby', noop: true, verbose: true)
Output:
chmod 755 src0.txt chmod 644 src0.txt src0.dat chmod u=wrx,go=rx src1.txt chmod u=wrx,go=rx /usr/bin/ruby
Related: FileUtils.chmod_R.
Like FileUtils.chmod, but changes permissions recursively.
Like FileUtils.chmod, but changes permissions recursively.
Changes the owner and group on the entries at the paths given in list (a single path or an array of paths) to the given user and group; returns list if it is an array, [list] otherwise:
Modifies each entry that is a regular file using File.chown.
Modifies each entry that is a symbolic link using File.lchown.
Argument list or its elements should be interpretable as paths.
User and group:
Argument user may be a user name or a user id; if nil or -1, the user is not changed.
Argument group may be a group name or a group id; if nil or -1, the group is not changed.
The user must be a member of the group.
Examples:
# One path. # User and group as string names. File.stat('src0.txt').uid # => 1004 File.stat('src0.txt').gid # => 1004 FileUtils.chown('user2', 'group1', 'src0.txt') File.stat('src0.txt').uid # => 1006 File.stat('src0.txt').gid # => 1005 # User and group as uid and gid. FileUtils.chown(1004, 1004, 'src0.txt') File.stat('src0.txt').uid # => 1004 File.stat('src0.txt').gid # => 1004 # Array of paths. FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat']) # Directory (not recursive). FileUtils.chown('user2', 'group1', '.')
Keyword arguments:
noop: true - does not change permissions; returns nil.
verbose: true - prints an equivalent command:
FileUtils.chown('user2', 'group1', 'src0.txt', noop: true, verbose: true) FileUtils.chown(1004, 1004, 'src0.txt', noop: true, verbose: true) FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat'], noop: true, verbose: true) FileUtils.chown('user2', 'group1', path, noop: true, verbose: true) FileUtils.chown('user2', 'group1', '.', noop: true, verbose: true)
Output:
chown user2:group1 src0.txt chown 1004:1004 src0.txt chown 1006:1005 src0.txt src0.dat chown user2:group1 src0.txt chown user2:group1 .
Related: FileUtils.chown_R.
Changes the owner and group on the entries at the paths given in list (a single path or an array of paths) to the given user and group; returns list if it is an array, [list] otherwise:
Modifies each entry that is a regular file using File.chown.
Modifies each entry that is a symbolic link using File.lchown.
Argument list or its elements should be interpretable as paths.
User and group:
Argument user may be a user name or a user id; if nil or -1, the user is not changed.
Argument group may be a group name or a group id; if nil or -1, the group is not changed.
The user must be a member of the group.
Examples:
# One path. # User and group as string names. File.stat('src0.txt').uid # => 1004 File.stat('src0.txt').gid # => 1004 FileUtils.chown('user2', 'group1', 'src0.txt') File.stat('src0.txt').uid # => 1006 File.stat('src0.txt').gid # => 1005 # User and group as uid and gid. FileUtils.chown(1004, 1004, 'src0.txt') File.stat('src0.txt').uid # => 1004 File.stat('src0.txt').gid # => 1004 # Array of paths. FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat']) # Directory (not recursive). FileUtils.chown('user2', 'group1', '.')
Keyword arguments:
noop: true - does not change permissions; returns nil.
verbose: true - prints an equivalent command:
FileUtils.chown('user2', 'group1', 'src0.txt', noop: true, verbose: true) FileUtils.chown(1004, 1004, 'src0.txt', noop: true, verbose: true) FileUtils.chown(1006, 1005, ['src0.txt', 'src0.dat'], noop: true, verbose: true) FileUtils.chown('user2', 'group1', path, noop: true, verbose: true) FileUtils.chown('user2', 'group1', '.', noop: true, verbose: true)
Output:
chown user2:group1 src0.txt chown 1004:1004 src0.txt chown 1006:1005 src0.txt src0.dat chown user2:group1 src0.txt chown user2:group1 .
Related: FileUtils.chown_R.
Like FileUtils.chown, but changes owner and group recursively.
Like FileUtils.chown, but changes owner and group recursively.
Updates modification times (mtime) and access times (atime) of the entries given by the paths in list (a single path or an array of paths); returns list if it is an array, [list] otherwise.
By default, creates an empty file for any path to a non-existent entry; use keyword argument nocreate to raise an exception instead.
Argument list or its elements should be interpretable as paths.
Examples:
# Single path. f = File.new('src0.txt') # Existing file. f.atime # => 2022-06-10 11:11:21.200277 -0700 f.mtime # => 2022-06-10 11:11:21.200277 -0700 FileUtils.touch('src0.txt') f = File.new('src0.txt') f.atime # => 2022-06-11 08:28:09.8185343 -0700 f.mtime # => 2022-06-11 08:28:09.8185343 -0700 # Array of paths. FileUtils.touch(['src0.txt', 'src0.dat'])
Keyword arguments:
mtime: time - sets the entry’s mtime to the given time, instead of the current time.
nocreate: true - raises an exception if the entry does not exist.
noop: true - does not touch entries; returns nil.
verbose: true - prints an equivalent command:
FileUtils.touch('src0.txt', noop: true, verbose: true) FileUtils.touch(['src0.txt', 'src0.dat'], noop: true, verbose: true) FileUtils.touch(path, noop: true, verbose: true)
Output:
touch src0.txt touch src0.txt src0.dat touch src0.txt
Related: FileUtils.uptodate?.
Updates modification times (mtime) and access times (atime) of the entries given by the paths in list (a single path or an array of paths); returns list if it is an array, [list] otherwise.
By default, creates an empty file for any path to a non-existent entry; use keyword argument nocreate to raise an exception instead.
Argument list or its elements should be interpretable as paths.
Examples:
# Single path. f = File.new('src0.txt') # Existing file. f.atime # => 2022-06-10 11:11:21.200277 -0700 f.mtime # => 2022-06-10 11:11:21.200277 -0700 FileUtils.touch('src0.txt') f = File.new('src0.txt') f.atime # => 2022-06-11 08:28:09.8185343 -0700 f.mtime # => 2022-06-11 08:28:09.8185343 -0700 # Array of paths. FileUtils.touch(['src0.txt', 'src0.dat'])
Keyword arguments:
mtime: time - sets the entry’s mtime to the given time, instead of the current time.
nocreate: true - raises an exception if the entry does not exist.
noop: true - does not touch entries; returns nil.
verbose: true - prints an equivalent command:
FileUtils.touch('src0.txt', noop: true, verbose: true) FileUtils.touch(['src0.txt', 'src0.dat'], noop: true, verbose: true) FileUtils.touch(path, noop: true, verbose: true)
Output:
touch src0.txt touch src0.txt src0.dat touch src0.txt
Related: FileUtils.uptodate?.
Returns an array of the string names of FileUtils methods that accept one or more keyword arguments:
FileUtils.commands.sort.take(3) # => ["cd", "chdir", "chmod"]
Returns the arc tangent of y and x in radians.
Domain of y: [-INFINITY, INFINITY].
Domain of x: [-INFINITY, INFINITY].
Range: [-PI, PI].
Examples:
atan2(-1.0, -1.0) # => -2.356194490192345 # -3*PI/4 atan2(-1.0, 0.0) # => -1.5707963267948966 # -PI/2 atan2(-1.0, 1.0) # => -0.7853981633974483 # -PI/4 atan2(0.0, -1.0) # => 3.141592653589793 # PI
Returns the arc tangent of x.
Domain: [-INFINITY, INFINITY].
Range: [-PI/2, PI/2] .
Examples:
atan(-INFINITY) # => -1.5707963267948966 # -PI2 atan(-PI) # => -1.2626272556789115 atan(-PI/2) # => -1.0038848218538872 atan(0.0) # => 0.0 atan(PI/2) # => 1.0038848218538872 atan(PI) # => 1.2626272556789115 atan(INFINITY) # => 1.5707963267948966 # PI/2
Returns the inverse hyperbolic tangent of x.
Domain: [-1, 1].
Range: [-INFINITY, INFINITY].
Examples:
atanh(-1.0) # => -Infinity atanh(0.0) # => 0.0 atanh(1.0) # => Infinity
Returns the value of the gamma function for x.
Domain: (-INFINITY, INFINITY] excluding negative integers.
Range: [-INFINITY, INFINITY].
Examples:
gamma(-2.5) # => -0.9453087204829431 gamma(-1.5) # => 2.3632718012073513 gamma(-0.5) # => -3.5449077018110375 gamma(0.0) # => Infinity gamma(1.0) # => 1.0 gamma(2.0) # => 1.0 gamma(3.0) # => 2.0 gamma(4.0) # => 6.0 gamma(5.0) # => 24.0
Related: Math.lgamma.
Returns a 2-element array equivalent to:
[Math.log(Math.gamma(x).abs), Math.gamma(x) < 0 ? -1 : 1]
See logarithmic gamma function.
Domain: (-INFINITY, INFINITY].
Range of first element: (-INFINITY, INFINITY].
Second element is -1 or 1.
Examples:
lgamma(-4.0) # => [Infinity, -1] lgamma(-3.0) # => [Infinity, -1] lgamma(-2.0) # => [Infinity, -1] lgamma(-1.0) # => [Infinity, -1] lgamma(0.0) # => [Infinity, 1] lgamma(1.0) # => [0.0, 1] lgamma(2.0) # => [0.0, 1] lgamma(3.0) # => [0.6931471805599436, 1] lgamma(4.0) # => [1.7917594692280545, 1] lgamma(-2.5) # => [-0.05624371649767279, -1] lgamma(-1.5) # => [0.8600470153764797, 1] lgamma(-0.5) # => [1.265512123484647, -1] lgamma(0.5) # => [0.5723649429247004, 1] lgamma(1.5) # => [-0.12078223763524676, 1] lgamma(2.5) # => [0.2846828704729205, 1]
Related: Math.gamma.
Avoids the potential for a child process to become a zombie process. Process.detach prevents this by setting up a separate Ruby thread whose sole job is to reap the status of the process pid when it terminates.
This method is needed only when the parent process will never wait for the child process.
This example does not reap the second child process; that process appears as a zombie in the process status (ps) output:
pid = Process.spawn('ruby', '-e', 'exit 13') # => 312691 sleep(1) # Find zombies. system("ps -ho pid,state -p #{pid}")
Output:
312716 Z
This example also does not reap the second child process, but it does detach the process so that it does not become a zombie:
pid = Process.spawn('ruby', '-e', 'exit 13') # => 313213 thread = Process.detach(pid) sleep(1) # => #<Process::Waiter:0x00007f038f48b838 run> system("ps -ho pid,state -p #{pid}") # Finds no zombies.
The waiting thread can return the pid of the detached child process:
thread.join.pid # => 313262
Returns the maximum number of group IDs allowed in the supplemental group access list:
Process.maxgroups # => 32
Sets the maximum number of group IDs allowed in the supplemental group access list.