REXX for OS/2
                                Test 015


TEST INFORMATION:

- Elective for Certified OS/2 Engineer and Certified LAN Server
  Engineer
- Number of questions:  121
- Passing % Score:      68
- Length (in minutes):  120


PREPARATION:

- Self Study

PUB # S10G6269     REXX User's Guide
PUB # S10G6268     REXX Reference Manual

- IBM Courses

P1066              REXX Programming for OS/2






































                                REXX for OS/2
                                Test 015 Objectives
                                Version 1

SECTION 1 - REXX BASICS

- Identify uses of REXX for OS/2.
- Identify features that make REXX for OS/2 a popular programming language.
- Identify features associated with REXX for OS/2:  possible components
  of a REXX for OS/2 installation, steps involved in creating and running
  an OS/2 REXX program, the distinction between an OS/2 REXX program and
  an OS/2 .CMD file, and the result of running a REXX for OS/2 program
  without the initial comment.
- Determine the difference between an interpretive vs. a compiled language;
  identify whether REXX for OS/2 is an interpretive or compiled language.
- Identify features and purpose of the tokenized image associated with a REXX program.            	
- Identify types of REXX clauses and how each type is handled by REXX.
- Identify features and uses of the various REXX tokens.
- Identify valid REXX expressions; use the order of precedence chart to resolve
  complex expressions.
- Identify and use the four types of REXX operators: string concatenation,
  arithmetic operators, comparison operators, and Boolean operators.
- Identify features of compound symbols, including their components and the
  constraints associated with them; given code examples, determine the
  results of using a compound symbol.

SECTION 2 - PROGRAM CONTROL

- Identify features of REXX branching instructions: IF-THEN-ELSE and SELECT;
  given code examples, determine the results of using these instructions.
- Identify features and components of DO groups and DO loops, including simple
  do groups, controlled repetitive loops, conditional loops, and the LEAVE and
  ITERATE instructions; given code examples, determine the results of using the
  various types of loops.

SECTION 3 - USING OS/2 COMMANDS

- Identify the REXX instruction used to pass commands to alternate external
  environments.
- Identify the three methods used to issue OS/2 commands from a REXX program.
- Given a set of code examples, determine the results of OS/2 commands
 -- both correctly and incorrectly coded.
- Identify when REXX determines that a clause is a command clause.
  identify how a command clause is treated by REXX.
- Identify when to use CALL vs. "CALL".
- Identify error conditions associated with issuing commands from a REXX program.
- Identify features and constraints of RC when used to capture OS/2 command
  return codes.


SECTION 4 - DEBUGGING TOOLS

- Identify features and constraints of REXX debugging tools, including REXXTRY,
  PMREXX, TRACE, interactive TRACE, and RXTRACE.

SECTION 5 - FUNCTIONS AND SUBROUTINES

- Identify features of REXX that foster adherence to structured programming techniques.
- Distinguish between REXX functions and subroutines.
- Identify features and constraints of internal routines; given code examples,
  determine the results of using internal routines.
- Given code examples, determine the contents of the RESULT special variable
  after execution of internal routines.
- Identify two ways in which to use the ARG statement; given code examples,
  determine the results of using ARG and PARSE ARG.
- Identify features and constraints of the ARG() built-in function; given
  a code example that uses the ARG() built-in function, determine the results.
- Identify features of the PROCEDURE and PROCEDURE EXPOSE instructions; given code
  examples, determine the results of using these instructions.
- Identify the search order REXX uses when it encounters a CALL instruction or
  function invocation.
- Identify the correct syntaxes for using a built-in function; given code examples
  and reference information, determine the results of using built-in functions.
- Given code examples, determine the results of using external routines.

SECTION 6 - QUEUES

- Given code examples, determine the results of using the PULL and PARSE PULL
  instructions, both when there is information on the queue and when the
  queue is empty; distinguish between PULL and PARSE PULL.
- Given code examples, determine the results of using the PUSH and QUEUE instructions.
- Given a code example using the QUEUED() function, determine the results.
- Identify features of the session queue.
- Identify features of private queues; given code examples, determine the results
  of using private queues, both within and between programs.
- Identify features of the RXQUEUE filter of OS/2; given code examples, determine
  the results of using the RXQUEUE filter.

SECTION 7 - PARSING

- Describe parsing and how it is used in REXX programs.
- Given several choices, identify the types of patterns that can be used to parse
  character strings.
- Given code examples that parse with words, determine the results.
- Identify the differences between PARSE VALUE and PARSE VAR.
- Given code examples, determine the results of using PARSE VALUE and PARSE VAR.
- Given code examples that parse with literal strings, determine the results.
- Given code examples that parse by position, determine the results.
- Given a code example that combines patterns (words, literals, position), determine
  the results.

SECTION 8 - HANDLING ERRORS

- Determine when the following conditions would be raised: ERROR, FAILURE, HALT,
  NOTREADY, NOVALUE, SYNTAX.
- Given a set of choices, determine the results when various conditions are raised
  and no traps have been set.
- Distinguish between the CALL ON and SIGNAL ON instructions; given code examples,
  determine the results of using these instructions.
- Given code examples, determine the results of using features provided by REXX
  which aid in error handling.


SECTION 9 - INPUT/OUTPUT

- Identify features of the REXX built-in functions that handle I/O.
- Given code examples, determine the results of using the REXX built-in functions
  that handle I/O.


SECTION 10 - REXX AND APPLICATIONS

- Given a set of choices, identify the most common way of extending the function of
  OS/2 REXX.
- Identify the prerequisite to using an external function package, including
  the type of instruction necessary to perform this prerequisite, frequency
  required for this prerequisite, and result of not
  performing this prerequisite.
- Given a set of choices, identify features of REXXUTIL.
- Identify features and constraints of the REXXUTIL functions that modify
  the Workplace Shell.


                                REXX for OS/2
                                Sample Test 015
                                Version 2

SECTION 1 - REXX BASICS

1. Which are valid REXX variables?

a.  4some
b.  some4
c.  !some4
d.  .some.4

2. Which character is used to separate multiple REXX clauses on the same line?

a.  ;
b.  ,
c.  :
d.  \

3. What is the result of the expression 3**2**2?

a.  12
b.  36
c.  64
d.  81

SECTION 2 - PROGRAM CONTROL

4. What is the final value of CTR after executing DO CTR = 1 to 25 by 5?

a.  21
b.  25
c.  26
d.  unknown

SECTION 3 - USING OS/2 COMMANDS

1)  /*   */
2)
3)  type filename
4)  "type" filename
5)  type filename "³ more"
6)  type filename ³ more

5. Given the above code sample and given that filename is a variable, which lines
would execute successfully?

a.  Line 3
b.  Line 4
c.  Line 5
d.  Line 6

6. Which conditions are associated with OS/2 commands?

a.  HALT
b.  ERROR
c.  FAILURE
d.  NOTREADY

SECTION 4 - DEBUGGING TOOLS

7. What are two ways to activate tracing without putting a trace
instruction in a program?

a.  PMREXX
b.  PMTRACE
c.  RXTRACE
d.  REXXTRY

8. When interactive trace pauses, which options are valid?

a.  pressing the + key
b.  pressing the enter key
c.  turning interactive trace off
d.  changing the source code

SECTION 5 - FUNCTIONS AND SUBROUTINES

9. What is the effect of the RETURN instruction in a main routine?

a.  It ends the program.
b.  It produces a syntax error.
c.  It returns to the beginning of the program.
d.  It displays a return value at the command prompt.

10. Which statements describe the ARG instruction?

a.  It leaves lowercase alphabetic characters in lowercase.
b.  It converts lowercase alphabetic characters to uppercase. 	
c.  It can be used to receive arguments from the queue.
d.  It can be used to receive arguments from the command prompt.

1)  /*  NAMES.CMD   */
2)  arg first second third
3)  say "first is "first
4)  say "second is "second
5)  say "third is "third

11. Given the above code sample and given that the program name is NAMES.CMD, if the
user runs it by typing  --  names Groucho Chico Harpo Zeppo -- at the command
prompt, what would line 5 display ?

a.  third is Harpo
b.  third is HARPO
c.  third is Harpo Zeppo
d.  third is HARPO ZEPPO

SECTION 6 - QUEUES

12. Which statements describe private queues?

a.  they can be deleted with RXQUEUE()
b.  they are deleted when the session is closed
c.  there can only be one private queue per OS/2 session
d.  there can be multiple private queues per OS/2 session

1)  /*  */
2)
3)  push "North"
4)  queue "South"
5)  push "East"
6)  queue "West"

13. Given that the queue is empty when the above program begins, which
item would be at the top of the queue after the program has run?

a.  North
b.  South
c.  East
d.  West

SECTION 7 - PARSING

1)  /*   */
2)
3)  pull name
4)  say name
5)  parse pull name
6)  say name

14. Given the above code sample and given that the session queue is
empty when the program begins, if at line 3 the user types in --
Franklin D. Roosevelt -- what would line 4 display  ?

a.  Franklin
b   FRANKLIN
c.  Franklin D. Roosevelt
d.  FRANKLIN D. ROOSEVELT

1)  /*   */
2)
3)  pull first last
4)  say "*"last"*"
5)  parse pull first last
6)  say "*"last"*"

15. Given the above code sample and given that the session queue is empty
when the program begins, if at line 5 the user types in --  Hans
Christian Andersen -- what would line 6 display?

a.  *Christian*
b   *CHRISTIAN*
c.  *Christian Andersen*
d.  *CHRISTIAN ANDERSEN*

1)  /*   */
2)
3)  address = "Florence Italy"
4)  parse var address city "," country
5)  say "*"city"*"
6)  say "*"country"*"

16. Given the above code sample, what would line 6 display?

a.  **
b   * *
c.  * Florence Italy*
d.  * FLORENCE ITALY*

SECTION 8 - HANDLING ERRORS

17. When does the FAILURE condition occur?

a.  when a syntax error occurs
b.  when Ctrl + Break is pressed
c.  when an input/output error occurs
d.  when an uninitialized variable is used
e.  when a command issues a non-zero return code
f.  when a severe error prevents processing of a command

18. What happens when the ERROR condition occurs and no trap has been set?

a.  The condition is ignored.
b.  Interactive trace is activated.
c.  The program issues a warning message.
d.  The program ends and a message is displayed.

SECTION 9 - INPUT/OUTPUT

19. Which statements describe the LINEIN() function ?

a.  Its initial position is top of file.
b.  Its initial position is end of file.
c.  It reads from the queue as a default.
d.  It reads from the keyboard as a default.

20. Which statements describe the LINEOUT() function?

a.  Its initial position is top of file.
b.  Its initial position is end of file.
c.  It can be called as a subroutine.
d.  It can be executed as a command.

SECTION 10 - REXX AND APPLICATIONS

21. Which REXXUTIL function is used to modify Workplace Shell objects?

a.  SysModifyObject
b.  SysSetObjectData
c.  WinModifyObject
d.  WinSetObjectData

22. Which REXXUTIL function is used to modify OS2.INI?

a.  SysIni
b.  SysModifyIni
c.  WinIni
d.  WinModifyIni


ANSWER KEY


1.  bc                                                             


2.  a

3.  d

4.  c

5.  abc

6.  bc

7.  ac

8.  bc

9.  a

10. bd

11. d

12. ad

13. c

14. d

15. c

16. a

17. f

18. a

19. ad

20. bc

21. b

22. a