12.5.21    info

Description:   Return information about the state of the Tcl interpreter and variables

Syntax:         info option ?arg arg ...?

         

Argument:     option, tclvars, variables, namespace, global variables

Returns:         0 or 1

See Also:       namespace, procedure, variable, tclvars, global

 

Examples:      #example 1

if {[info exists tcl_platform(user)]} {

     set user $tcl_platform(user)

} elseif {[info exists env(USERNAME)]}  {

     set user $env(USERNAME)

} else   {set user {}}

 

This command provides information about various internals of the Tcl interpreter. The option’s (which may be abbreviated) are:

info args procname

Returns a list of the arguments to procedure procname. Procname must be a Tcl command procedure.

info body procname

Returns the body of procedure procname.  

info cmdcount

Returns a count of the total number of commands that have been invoked in this interpreter.

info commands ?pattern?

If pattern isn’t specified, returns a list of names of all the Tcl commands in the current namespace, including both the built-in commands and the command procedures defined using the proc command. If pattern is specified, only those names matching pattern are returned. Matching is determined using the same rules as for string match. It may specify a particular namespace using a sequence of namespace names separated by ::s, and may have pattern matching special characters at the end to specify a set of commands in that namespace. If pattern is a qualified name, the resulting list of command names has each one qualified with the name of the specified namespace.

info complete command

Returns 1 if command is a complete Tcl command in the sense of having no unclosed quotes, braces, brackets or array element names, If the command doesn’t appear to be complete then 0 is returned. This command is typically used in line-oriented input environments to allow users to type in commands that span multiple lines; if the command isn’t complete, the script can delay evaluating it until additional lines have been typed to complete the command.

info default procname arg varname

Procname must be the name of a Tcl command procedure and arg must be the name of an argument to that procedure. If arg doesn't’t have a default value then the command returns 0. Otherwise it returns 1 and places the default value of arg into variable varname.

info exists varName

Returns 1 if the variable named varName exists in the current context (either as a global or local variable), returns 0 otherwise.

info globals ?pattern?

If pattern isn’t specified, returns a list of all the names of currently defined global variables. Global variables are variables in the global namespace. If pattern is specified, only those names matching pattern are returned. Matching is determined using the same rules as for string match.

info hostname

Returns the name of the computer on which this invocation is being executed.

info level ?number?

If number is not specified, this command returns a number giving the stack level of the invoking procedure, or 0 if the command is invoked at top-level. If number is specified, then the result is a list consisting of the name and arguments for the procedure call at level number on the stack. If number is positive then it selects a particular stack level (1 refers to the top-most active procedure, 2 to the procedure it called, and so on); otherwise it gives a level relative to the current level (0 refers to the current procedure, -1 to its caller, and so on). See the uplevel command for more information on what stack levels mean.

info library

Returns the name of the library directory in which standard Tcl scripts are stored. This is actually the value of the tcl_library variable and may be changed by setting tcl_library. See the tclvars manual for more information.

info locals ?pattern?

If pattern isn’t specified, returns a list of all the names of currently defined local variables, including arguments to the current procedure, if any. Variables defined with the global and upvar commands will not be returned. If pattern is specified, only those names matching pattern are returned. Matching is determined using the same rules as for string match.

info nameofexecutable

Returns the full path name of the binary file from which the application was invoked. If Tcl was unable to identify the file, then an empty string is returned.

info patchlevel

Returns the value of the global variable tcl_patchLevel; see the tclvars manual entry for more information.

info procs ?pattern?

If pattern isn’t specified, returns a list of all the names of Tcl command procedures in the current namespace. If pattern is specified, only those procedure names in the current namespace matching pattern are returned. Matching is determined using the same rules as for string match.

info script

If a Tcl script file is currently being evaluated (i.e. there is a call to Tcl_EvalFile active or there is an active invocation of the source command), then this command returns the name of the innermost file being processed. Otherwise the command returns an empty string.

info tclversion

Returns the value of the global variable tcl_version; see the tclvars manual for more information.

info vars ?pattern?

If pattern isn’t specified, returns a list of all the names of currently visible variables. This includes locals and currently visible globals. If pattern is specified, only those names matching pattern are returned. Matching is determined using the same rules as for string match. pattern can be a  particular namespace using a sequence of namespace names separated by ::s, and may have pattern matching special characters at the end

to specify a set of variables in that namespace. If pattern is a qualified name, the resulting list of variable names has each matching namespace variable qualified with the name of its namespace.