uplevel

Execute a script in the context of a caller's stack frame.

Syntax

uplevel ?level? command ?arg ...?

Parameters

• level: Stack level to execute in (default: 1). Can be:
  • A relative level N - moves N levels up the call stack
  • An absolute level #N - targets absolute stack frame number
• command: The command to execute
• arg: Additional arguments concatenated with command (joined with spaces)

Description

The uplevel command evaluates a script in a different stack frame context:

1. Parses an optional level specifier (relative N or absolute #N)
2. Defaults to level 1 (caller's frame) when level is omitted
3. Concatenates multiple arguments with spaces to form the script
4. Temporarily switches the active frame to the target level
5. Evaluates the script in that frame's variable context
6. Returns the result of the script evaluation

Supported Features

Feature	Notes
Relative level (N)	Moves N levels up the call stack
Absolute level (#N)	Targets absolute stack frame number
Default level of 1	Used when level is omitted
Multiple argument concatenation	Arguments are joined with spaces
Variable context switching	Script executes with target frame's variables
Result propagation	Returns result of evaluated script
Error propagation	Errors from script evaluation are propagated
Namespace interaction	Namespace eval and procs add call frames correctly
Apply command interaction	Apply adds call frames that count for uplevel

Examples

Output

See Also

• upvar
• proc
• apply
• namespace