Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #700
Difficulty: Medium
In the theory of Vernadsky, the noosphere is the fifth in a succession of phases of related to the development of the Earth.
True or False?
Linux & Unix Commands - Search Man Pages

variable(n) [centos man page]

variable(n)						       Tcl Built-In Commands						       variable(n)

__________________________________________________________________________________________________________________________________________________

NAME
variable - create and initialize a namespace variable SYNOPSIS
variable ?name value...? name ?value? _________________________________________________________________ DESCRIPTION
This command is normally used within a namespace eval command to create one or more variables within a namespace. Each variable name is initialized with value. The value for the last variable is optional. If a variable name does not exist, it is created. In this case, if value is specified, it is assigned to the newly created variable. If no value is specified, the new variable is left undefined. If the variable already exists, it is set to value if value is specified or left unchanged if no value is given. Normally, name is unqualified (does not include the names of any containing namespaces), and the variable is created in the current namespace. If name includes any namespace qualifiers, the variable is created in the specified names- pace. If the variable is not defined, it will be visible to the namespace which command, but not to the info exists command. If the variable command is executed inside a Tcl procedure, it creates local variables linked to the corresponding namespace variables (and therefore these variables are listed by info vars.) In this way the variable command resembles the global command, although the global command only links to variables in the global namespace. If any values are given, they are used to modify the values of the associated namespace variables. If a namespace variable does not exist, it is created and optionally initialized. A name argument cannot reference an element within an array. Instead, name should reference the entire array, and the initialization value should be left off. After the variable has been declared, elements within the array can be set using ordinary set or array commands. EXAMPLES
Create a variable in a namespace: namespace eval foo { variable bar 12345 } Create an array in a namespace: namespace eval someNS { variable someAry array set someAry { someName someValue otherName otherValue } } Access variables in namespaces from a procedure: namespace eval foo { proc spong {} { # Variable in this namespace variable bar puts "bar is $bar" # Variable in another namespace variable ::someNS::someAry parray someAry } } SEE ALSO
global(n), namespace(n), upvar(n) KEYWORDS
global, namespace, procedure, variable Tcl 8.0 variable(n)

Check Out this Related Man Page

global(1T)						       Tcl Built-In Commands							global(1T)

__________________________________________________________________________________________________________________________________________________

NAME
global - Access global variables SYNOPSIS
global varname ?varname ...? _________________________________________________________________ DESCRIPTION
This command has no effect unless executed in the context of a proc body. If the global command is executed in the context of a proc body, it creates local variables linked to the corresponding global variables (and therefore these variables are listed by info locals). If varname contains namespace qualifiers, the local variable's name is the unqualified name of the global variable, as determined by the namespace tail command. EXAMPLES
This procedure sets the namespace variable ::a::x proc reset {} { global a::x set x 0 } This procedure accumulates the strings passed to it in a global buffer, separated by newlines. It is useful for situations when you want to build a message piece-by-piece (as if with puts) but send that full message in a single piece (e.g. over a connection opened with socket or as part of a counted HTTP response). proc accum {string} { global accumulator append accumulator $string } SEE ALSO
namespace(1T), upvar(1T), variable(1T) KEYWORDS
global, namespace, procedure, variable ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +--------------------+-----------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +--------------------+-----------------+ |Availability | SUNWTcl | +--------------------+-----------------+ |Interface Stability | Uncommitted | +--------------------+-----------------+ NOTES
Source for Tcl is available on http://opensolaris.org. Tcl global(1T)

Featured Tech Videos