option of the history command to reexecute a specific command You can specify

option of the history command to reexecute a specific command. You can specify the command to reexecute by its event number or by a relative event number. The following command executes the command whose event number is 54: prompt> history redo 54 The following command reexecutes the second-to-the-last command: prompt> history redo -2 If you do not specify an event number, the last command entered is reexecuted. As a shortcut, you can also use the exclamation point operator (!) for reexecuting commands. For example, to reexecute the last command, enter prompt> !! To reexecute the command whose event number is 6, enter prompt> !6 Note: The Synopsys implementation of history varies from the Tcl implementation. For usage information about the history command, see the Synopsys man pages. Getting Help on Commands To get help about a command or variable, use the help or man command. Additionally, you can display a command’s options and arguments by using the -help option. For example, prompt> create_clock -help Usage: create_clock # create clock [-name clock_name] (name for the clock) [-period period_value] (period of the clock: Value >= 0) [-waveform edge_list] (alternating rise, fall times for 1 period) [-add] (add to the existing clock in port_pin_list) [source_objects] (list of ports and/or pins) Note: To distinguish between Tcl and Synopsys commands, the Synopsys help and man commands categorize Tcl commands as built-in commands and Tcl built-in commands, respectively.

Using Tcl With Synopsys® Tools 41 Q-2019.12 Chapter 2: Commands Getting Help on Commands Using the help Command You can use the help command to get information about the commands available in the tool. The syntax for the help command is: help [-verbose] [ pattern ] where the arguments are as follows: -verbose Displays a short description of the command arguments. pattern Specifies a command pattern to match. To list all commands that match a pattern, specify it as an argument to the help command: prompt> help *upf* To report the usage information for one or more commands, including arguments and option information, use the -verbose option: prompt> help check* -verbose To get a list of all commands in a particular command group, specify the group name as an argument to the help command: prompt> help {DRC Errors} Using the man Command To get help from the Synopsys man pages, use the man command, as shown: prompt> man query_objects The man pages provide detailed information about commands and variables. The syntax for the man command is man topic The topic argument can be a command or a topic. For example, you can get information about a specific command, such as query_objects , or you can get information about a topic, such as attributes. The man pages are also available on SolvNet.

Using Tcl With Synopsys® Tools 42 Q-2019.12 Chapter 2: Commands Tcl Limitations Within the Command-Line Interface Tcl Limitations Within the Command-Line Interface Generally, the command-line interface implements all the Tcl built-in commands. However, the command-line interface adds semantics to some Tcl built-in commands and imposes restrictions on some elements of the language. These differences are as follows: