Tcl_1_2015.00_LG_03 S公司2015年tcl教程Lab guide

Play with Strings3and ListsPlay with Strings and Lists Lab 3-1Lab 3Lab 3-2 Play with Strings and ListsThe Power of Tcl 1: Becoming a Proficient Tcl UserLab OverviewDuring this lab, you will build a broad and useful command repertoire formanipulating strings and lists.Answers & SolutionsThis lab guide contains answers and solutions to all questions. If you need help answering a question or would like to confirm your results, check the back portion of this document. Lab TasksCreate a useful command while applyingthe commands learned in lectureLAB 2Learn skills that will be essential everytime you write Tcl scriptsLAB 3Master the commands to count patterns instrings, and gain comfort with the basiccomponents of a Tcl scriptLAB 1Lab 3 File LocationsDirectory Structuredesign_data ORCA netlistscripts Constraint and run scriptslibs Technology librariestcl_procs Tcl procedures and solutions.synopsys_pt.setup PrimeTime setup file.synopsys_dc.setup Design Compiler setup fileRelevant Filesscripts/rpt_TNV.tcl Incomplete TNV commandrun.tcl Reads the ORCA designtcl_procs/rpt_TNV.tcl Full TNV solution for homeworklist_sub.tcl Solution for Q25 in Task 5pin_match.tcl Solution for Q26 in Task 5Play with Strings and Lists Lab 3-3 The Power of Tcl 1: Becoming a Proficient Tcl UserLab 3Lab InstructionsTask 1.Playing With Tcl StringsBefore applying strings to real world examples, you will go through some basicexamples to gain an understanding of what strings are all about.The skills learned will be useful in the future whenever you explore new Tclcommands or forget how to use commands you learned in the past.1.Invoke either Design Compiler or PrimeTime.There is no need to read a design for the following exercises.All subsequent instructions are generic for either tool - DesignCompiler or PrimeTime.1.Create two strings by executing the following commands.e the command regexp –all to count patterns in a string.Question 1. How many letter l’s are in the string captured by variable a(you should get 3)?....................................................................................................Question 2. How many newlines in the string captured by variable b (youshould get 2)?.................................................................................................... Lab 3-4 Play with Strings and ListsThe Power of Tcl 1: Becoming a Proficient Tcl UserLab 33.Count the total number of characters in a string using the command stringlength. Execute the following example.Question 3. Did the above exercise confirm that spaces and newlinescount as individual characters in strings?....................................................................................................4.Determine if a string matches a pattern using globbing and the commandstring match.For string matching to succeed (i.e. the return value is 1), the pattern and thestring must be identical except that the pattern may include wildcardcharacters such as *.Question 4. Did the above commands work as expected?....................................................................................................5.Extract characters from a string using the command string index.Question 5. Does the index range start at 1 or 0 (i.e. to get the firstcharacter in a string, do you use an index of 1 or 0)?....................................................................................................Question 6. Do you need to know the total number of characters in astring to extract the LAST character of the string?.................................................................................................... Play with Strings and Lists Lab 3-5 The Power of Tcl 1: Becoming a Proficient Tcl UserLab 3Question 7. From your own experimentation, what will string indexreturn if you provide an index outside the range of theprovided string argument?....................................................................................................e the string command to find the index of the last \nt (a newline followedby the letter t) in the string captured by the variable b.Use the relevant portion of the man page for the string command shownbelow.string last string1 string2Search string2 for a sequence of characters that exactly match thecharacters in string1. If found, return the index of the firstcharacter in the last such match within string2. If there is nomatch, then return -1.Question 8. What is the index of the first character of the last \nt in thestring captured by variable b?....................................................................................................7.Append strings using the append command.Question 9. After executing the above command, was the value ofvariable a modified?....................................................................................................Question 10. Does the append command add spaces when it concatenatesstrings?....................................................................................................8.Visually identify the string commands used so far on job aid #1.Lab 3-6 Play with Strings and ListsThe Power of Tcl 1: Becoming a Proficient Tcl UserLab 3 Task 2.Playing With Tcl ListsPerform the same type of exercises with Tcl lists.1.Create two Tcl lists by executing the following lines.2.Count the total number of elements in each list using the Tcl commandllength.Question 11. Explain why the last example above returned a value of 1?....................................................................................................Question 12. Do spaces count as individual list elements?....................................................................................................3.Play with list indices. Extract list elements using the command lindex.Question 13. Write the command to extract the last element from a list.Use your experience with string indices, or use the man pagefor lindex..................................................................................................... Play with Strings and Lists Lab 3-7 The Power of Tcl 1: Becoming a Proficient Tcl UserLab 3Lab 3-8 Play with Strings and ListsThe Power of Tcl 1: Becoming a Proficient Tcl User4.Determine if any list element matches a pattern using lsearch –glob .Question 14. What does lsearch –glob return if the match is successful and what does it return if the match is NOT successful? .................................................................................................... 5.Insert items into a list using the command linsert . Question 15. Did the above command modify the variable b ? .................................................................................................... Question 16. Rewrite the above command such that the value of variable b is modified to be "zero one two three". .................................................................................................... 6.Append lists together using the command lappend .Question 17. After executing the first command above, was the value of variable b modified? .................................................................................................... Question 18. Does lappend add spaces when appending elements to a list? .................................................................................................... Question 19. Can individual list elements themselves be lists? ....................................................................................................Lab 37.Iterate over every element of a list using the command foreach.Question 20. How many times does the foreach command iterate?....................................................................................................Question 21. What is the user defined variable list_element set to duringeach iteration?....................................................................................................8.Visually identify the list commands used so far on job aid #1.Task 3.Convert Strings Into Lists and Back AgainFor the last exercise, perform the same type of “hello world” exercises converti ngstrings to lists and back to strings.1.Create two strings by executing the following command.2.Convert a string to a list using the split command.Question 22. Do the splitChars remain in the resulting list?....................................................................................................Question 23. Do spaces from the original string remain in the resulting list?.................................................................................................... Play with Strings and Lists Lab 3-9 The Power of Tcl 1: Becoming a Proficient Tcl UserLab 33.Convert a list back to a string using the join command.Question 24. Describe the result of the last command executed above.....................................................................................................4.Quit the Synopsys tool and return to lecture. This completes the workshoplabs.Task 4.Optional Homework: Complete rpt_TNV.tclPlease look at the foils in the appendix of Unit 4 for a description of the problemyou will be solving in this task.1.Invoke either Design Compiler or PrimeTime using the script ./scripts/run.tcl2.Play with your starting point by sourcing the procedure contained in./scripts/rpt_TNV.tcl and executing the command rpt_TNV.3.Edit the procedure in ./scripts/rpt_TNV.tcl such that the total number ofviolations is reported for each individual group (each clock group as well aseach group of design rule violations).One example solution is contained in ./tcl_procs/rpt_TNV.tcl Task 5. Writing Custom ScriptsQuestion 25. Write a Tcl script to subtract list_2 elements from list_1 elements(i.e. list1 – list 2) (Create list1 to be “dc pt mw icc1” and list2 to be “pt icc2 mw”)……………………………………………………………………Question 26. Write a Tcl script to check if a pin exists in the input list, and if soreport the net to which it is connected. (The input list is given as“I_ORCA_TOP/pad_in[10] I_ORCA_TOP/pad_in[5]I_ORCA_TOP/sd_DQ_in[11]”)……………………………………………………………………..Lab 3-10 Play with Strings and ListsThe Power of Tcl 1: Becoming a Proficient Tcl UserAnswers / SolutionsTask 1.Playing with Tcl StringsQuestion 1. How many letter l’s are in the string captured by thevariable a?Question 2. How many newlines are in the string captured by thevariable b?Question 3. Did the above exercise confirm that spaces and newlinescount as individual characters in strings?Yes. The command string length will count everycharacter in a string, which includes newlines and spacesrepresenting a single character. The double quotes that wereused to create the string in the first place are not part of theactual string and are not counted in the string length.Question 4. Did the above commands work as expected?The first command succeeds because the pattern completelymatches the string.The second command fails. The pattern and the string mustbe identical. The pattern two* does not completely matchthe string! The following example will return a successfulmatch (notice the wildcard * matches newlines as well).Question 5. Does the index range start at 1 or 0 (i.e. to get the firstcharacter in a string, do you use an index or 1 or 0)?0. You will notice later that this is consistent with listindexing as well.Lab 3-12 Play with Strings and ListsQuestion 6. Do you need to know the total number of characters in astring to extract the LAST character of the string?No. You can use the string index end to extract the lastcharacter.Question 7. From your own experimentation, what will string indexreturn if you provide an index outside the range of theprovided string argument?The command returns the empty string.Question 8.What is the index of the first character of the last \nt in thestring captured by variable b ?Question 9. After executing the above command, was the value ofvariable a modified?Yes. Certain commands ask for the variable name and willmodify the variable value. Other commands will modify thestring itself (not the variable). To confirm, use printvar asshown below. Also shown is the relevant portion of theman page where it clearly asks for the variable itself.printvar a→ a = "hello worldonetwothree"man appendNAMEappend - Append to variable SYNOPSISappend varName ?value value value ...?DESCRIPTIONAppend all of the value arguments to the current value of variable varName.Question 10. Does the append command add spaces when it concatenatesstrings?No, it does not.Task 2.Playing with Tcl ListsQuestion 11. Explain why the last example above returned a value of 1.The last command returns the length of the list “b” whichhas one list element (named b). Notice this is different fromthe second to last command which is using the value of thevariable named b (which is set to "one two three" and hasthree list elements).Question 12. Do spaces count as individual list elements?Spaces are used to separate list elements and are not countedas list elements themselves. If you wanted to include aspace as a list element, you will have to do something likethe following example.Question 13. Write the command to extract the last element from a list.Use your experience with string indices, or use the manpage for lindex.String and list indices are consistent. Following is thecorrect command and the relevant portion of the man page. lindex $a endman lindex. . . If index has the value end, it refers to the last element in the list, and end-integer refers to the last element in the list minus the specified integer offset.Question 14. What does lsearch –glob return if the match is successfuland what does it return if the match is NOT successful?This command returns the list index of the 1st matching listelement if successful (recall the first list index starts at 0!).It returns –1 if not successful. This matches the relevantportion of the man page shown below.DESCRIPTIONThis command searches the elements of list to see if one of themmatches pattern. If so, the command returns the index of the first matching element. If not, the command returns -1.Question 15. Did the above command modify the variable b?No, the variable b is still “one two three”.Question 16. Rewrite the above command such that the value of variableb is modified to be "zero one two three".Question 17. After executing the first command above, was the value ofvariable b modified?Yes, in this example the variable b WAS modified. Useprintvar to validate this.Question 18. Does lappend add spaces when appending elements to alist?Spaces are used to separate elements in a list. Therefore,lappend MUST add spaces when appending list elements. Lab 3-14 Play with Strings and ListsQuestion 19. Can individual list elements themselves be lists?Yes. This is shown in the last example as shown below.The list captured by the variable b is appended to a as asingle list element.Question 20. How many times does the foreach command iterate?In this example, 3 times – once for every list element in a. Question 21. What is the user defined variable list_element set to during each iteration?It is set to each subsequent item in the original list a. Theresult of the foreach iteration is shown below.Task 3.Convert Strings Into Lists and Back Again Question 22. Do the splitChars remain in the resulting list?No, they do not. The splitChars are removed as well asidentify where the original string should be split into theresulting list.Question 23. Do spaces from the original string remain in the resultinglist?Yes they do. If an individual list element contains spaces, itwill be shown with { } to identify it as a single list elementas shown in the example below.# The o is removed from the resulting list# The space in the original list is part of the second list element# The resulting list contains 3 list elementssplit $a o→ hell { w} rld# A different example.# Notice the space is kept as part of the second list elementsplit $a e→ h {llo world}# Notice now that space is used as a splitting element# The space is removed and the resulting list is split accordinglysplit $a "e "→ h llo worldQuestion 24. Describe the result of the last command executed above.The final result is a string where all letter o’s in the origina lstring are replaced by the number 5.Task 5. Writing Custom ScriptsQuestion 25. Write a Tcl script to subtract list_2 elements from list_1 elements(i.e. list1 – list 2)proc list_sub { lis1 lis2 } {set result ""foreach el $lis1 {if {[lsearch -exact $lis2 $el] == -1} {lappend result $el}}return $result}Lab 3-16 Play with Strings and ListsQuestion 26. Write a Tcl script to check if a pin exists in the input list, and if so report the net to which it is connected. (The input list is given as “I_ORCA_TOP/pad_in[10]I_ORCA_TOP/pad_in[5] I_ORCA_TOP/sd_DQ_in[11]”)set my_pins [list I_ORCA_TOP/pad_in[10] I_ORCA_TOP/pad_in[5]I_ORCA_TOP/sd_DQ_in[11]]proc match_pins { pin_name } {global my_pinsif {[lsearch -exact $my_pins $pin_name ] != -1} {set net [get_object_name [get_attribute [get_pins $pin_name -quiet] net]]puts "The pin $pin_name is connected to the net $net"} else {puts "No pin found"}}Note: In the above script try replacing the “-exact” switch with “-glob” or “-regexp” and check what the script outputs.。