Trace-Command
SYNOPSIS
Configures and starts a trace of the specified expression or command.
SYNTAX
expressionSet (Default)
Trace-Command [-InputObject <PSObject>] [-Name] <String[]> [[-Option] <PSTraceSourceOptions>]
[-Expression] <ScriptBlock> [-ListenerOption <TraceOptions>] [-FilePath <String>] [-Force] [-Debugger]
[-PSHost] [<CommonParameters>]
commandSet
Trace-Command [-InputObject <PSObject>] [-Name] <String[]> [[-Option] <PSTraceSourceOptions>]
[-Command] <String> [-ArgumentList <Object[]>] [-ListenerOption <TraceOptions>] [-FilePath <String>] [-Force]
[-Debugger] [-PSHost] [<CommonParameters>]
DESCRIPTION
The `Trace-Command` cmdlet configures and starts a trace of the specified expression or command. It works like Set-TraceSource, except that it applies only to the specified command.
EXAMPLES
Example 1: Trace metadata processing, parameter binding, and an expression
Trace-Command -Name metadata,parameterbinding,cmdlet -Expression {Get-Process Notepad} -PSHost
It uses the Name parameter to specify the trace sources, the Expression parameter to specify the command, and the PSHost parameter to send the output to the console. Because it does not specify any tracing options or listener options, the command uses the defaults:
- All for the tracing options
- None for the listener options
Example 2: Trace the actions of ParameterBinding operations
$A = "i*"
Trace-Command ParameterBinding {Get-Alias $Input} -PSHost -InputObject $A
In `Trace-Command`, the InputObject parameter passes an object to the expression that is being processed during the trace.
The first command stores the string `i*` in the `$A` variable. The second command uses the `Trace-Command` cmdlet with the ParameterBinding trace source. The PSHost parameter sends the output to the console.
The expression being processed is `Get-Alias $Input`, where the `$Input` variable is associated with the InputObject parameter. The InputObject parameter passes the variable `$A` to the expression. In effect, the command being processed during the trace is `Get-Alias -InputObject $A" or "$A | Get-Alias`.
PARAMETERS
-ArgumentList
Specifies the parameters and parameter values for the command being traced. The alias for ArgumentList is Args . This feature is especially useful for debugging dynamic parameters.
For more information about the behavior of ArgumentList , see about_Splatting (../Microsoft.PowerShell.Core/About/about_Splatting.md#splatting-with-arrays).
Type: System.Object[]
Parameter Sets: commandSet
Aliases: Args
Required: False
Position: Named
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Command
Specifies a command that is being processed during the trace.
Type: System.String
Parameter Sets: commandSet
Aliases:
Required: True
Position: 1
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Debugger
Indicates that the cmdlet sends the trace output to the debugger. You can view the output in any user-mode or kernel mode debugger or in Visual Studio. This parameter also selects the default trace listener.
Type: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False
-Expression
Specifies the expression that is being processed during the trace. Enclose the expression in braces (`{}`).
Type: System.Management.Automation.ScriptBlock
Parameter Sets: expressionSet
Aliases:
Required: True
Position: 1
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-FilePath
Specifies a file that the cmdlet sends the trace output to. This parameter also selects the file trace listener.
Type: System.String
Parameter Sets: (All)
Aliases: PSPath, Path
Required: False
Position: Named
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Force
Forces the command to run without asking for user confirmation. Used with the FilePath parameter. Even using the Force parameter, the cmdlet cannot override security restrictions.
Type: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False
-InputObject
Specifies input to the expression that is being processed during the trace. You can enter a variable that represents the input that the expression accepts, or pass an object through the pipeline.
Type: System.Management.Automation.PSObject
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: None
Accept pipeline input: True (ByValue)
Accept wildcard characters: False
-ListenerOption
Specifies optional data to the prefix of each trace message in the output. The acceptable values for this parameter are:
- `None`
- `LogicalOperationStack`
- `DateTime`
- `Timestamp`
- `ProcessId`
- `ThreadId`
- `Callstack`
`None` is the default.
These values are defined as a flag-based enumeration. You can combine multiple values together to set multiple flags using this parameter. The values can be passed to the ListenerOption parameter as an array of values or as a comma-separated string of those values. The cmdlet will combine the values using a binary-OR operation. Passing values as an array is the simplest option and also allows you to use tab-completion on the values.
Type: System.Diagnostics.TraceOptions
Parameter Sets: (All)
Aliases:
Accepted values: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack
Required: False
Position: Named
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Name
Specifies an array of PowerShell components that are traced. Enter the name of the trace source of each component. Wildcards are permitted. To find the trace sources on your computer, type `Get-TraceSource`.
Type: System.String[]
Parameter Sets: (All)
Aliases:
Required: True
Position: 0
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-Option
Determines the type of events that are traced. The acceptable values for this parameter are:
- `None`
- `Constructor`
- `Dispose`
- `Finalizer`
- `Method`
- `Property`
- `Delegates`
- `Events`
- `Exception`
- `Lock`
- `Error`
- `Errors`
- `Warning`
- `Verbose`
- `WriteLine`
- `Data`
- `Scope`
- `ExecutionFlow`
- `Assert`
- `All`
`All` is the default.
The following values are combinations of other values:
- `ExecutionFlow`: `Constructor`, `Dispose`, `Finalizer`, `Method`, `Delegates`, `Events`, `Scope`
- `Data`: `Constructor`, `Dispose`, `Finalizer`, `Property`, `Verbose`, `WriteLine`
- `Errors`: `Error`, `Exception`
These values are defined as a flag-based enumeration. You can combine multiple values together to set multiple flags using this parameter. The values can be passed to the Option parameter as an array of values or as a comma-separated string of those values. The cmdlet will combine the values using a binary-OR operation. Passing values as an array is the simplest option and also allows you to use tab-completion on the values.
Type: System.Management.Automation.PSTraceSourceOptions
Parameter Sets: (All)
Aliases:
Accepted values: None, Constructor, Dispose, Finalizer, Method, Property, Delegates, Events, Exception, Lock, Error, Errors, Warning, Verbose, WriteLine, Data, Scope, ExecutionFlow, Assert, All
Required: False
Position: 2
Default value: None
Accept pipeline input: False
Accept wildcard characters: False
-PSHost
Indicates that the cmdlet sends the trace output to the PowerShell host. This parameter also selects the PSHost trace listener.
Type: System.Management.Automation.SwitchParameter
Parameter Sets: (All)
Aliases:
Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False
CommonParameters
This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutVariable, -OutBuffer, -PipelineVariable, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters.
INPUTS
System.Management.Automation.PSObject
You can pipe objects that represent input to the expression to `Trace-Command`.
OUTPUTS
System.Management.Automation.PSObject
Returns the command trace in the debug stream.
NOTES
- Tracing is a method that developers use to debug and refine programs. When tracing, the program generates detailed messages about each step in its internal processing.
- The PowerShell tracing cmdlets are designed to help PowerShell developers, but they are available to all users. They let you monitor nearly every aspect of the functionality of the shell.
- To find the PowerShell components that are enabled for tracing, type `Get-Help Get-TraceSource`.
A trace source is the part of each PowerShell component that manages tracing and generates trace messages for the component. To trace a component, you identify its trace source.
A trace listener receives the output of the trace and displays it to the user. You can elect to send the trace data to a user-mode or kernel-mode debugger, to the host or console, to a file, or to a custom listener derived from the System.Diagnostics.TraceListener class.
- When you use the commandSet parameter set, PowerShell processes the command just as it would be processed in a pipeline. For example, command discovery is not repeated for each incoming object.
- The names of the Name , Expression , Option , and Command parameters are optional. If you omit the parameter names, the unnamed parameter values must appear in this order: Name , Expression , Option or Name , Command , Option . If you include the parameter names, the parameters can appear in any order.