DOCSLIB.ORG

Debugging Makefiles Is Somewhat of a Black Art

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

,ch12.8053 Page 229 Friday, March 25, 2005 2:55 PM Chapter 12 CHAPTER 12 Debugging Makefiles Debugging makefiles is somewhat of a black art. Unfortunately, there is no such thing as a makefile debugger to examine how a particular rule is being evaluated or a variable expanded. Instead, most debugging is performed with simple print state- ments and by inspection of the makefile. GNU make provides some help with various built-in functions and command-line options. One of the best ways to debug a makefile is to add debugging hooks and use defen- sive programming techniques that you can fall back on when things go awry. I’ll present a few basic debugging techniques and defensive coding practices I’ve found most helpful. Debugging Features of make The warning function is very useful for debugging wayward makefiles. Because the warning function expands to the empty string, it can be placed anywhere in a makefile: at the top-level, in target or prerequisite lists, and in command scripts. This allows you to print the value of variables wherever it is most convenient to inspect them. For example: $(warning A top-level warning) FOO := $(warning Right-hand side of a simple variable)bar BAZ = $(warning Right-hand side of a recursive variable)boo $(warning A target)target: $(warning In a prerequisite list)makefile $(BAZ) $(warning In a command script) ls $(BAZ): yields the output: $ make makefile:1: A top-level warning makefile:2: Right-hand side of a simple variable makefile:5: A target 229 This is the Title of the Book, eMatter Edition Copyright © 2005 O’Reilly & Associates, Inc. All rights reserved. ,ch12.8053 Page 230 Friday, March 25, 2005 2:55 PM makefile:5: In a prerequisite list makefile:5: Right-hand side of a recursive variable makefile:8: Right-hand side of a recursive variable makefile:6: In a command script ls makefile Notice that the evaluation of the warning function follows the normal make algorithm for immediate and deferred evaluation. Although the assignment to BAZ contains a warning, the message does not print until BAZ is evaluated in the prerequisites list. The ability to inject a warning call anywhere makes it an essential debugging tool. Command-Line Options There are three command-line options I find most useful for debugging: --just- print (-n), --print-data-base (-p), and --warn-undefined-variables. --just-print The first test I perform on a new makefile target is to invoke make with the --just- print (-n) option. This causes make to read the makefile and print every command it would normally execute to update the target but without executing them. As a con- venience, GNU make will also echo commands marked with the silent modifier (@). The option is supposed to suppress all command execution. While this may be true in one sense, practically speaking, you must take care. While make will not execute command scripts, it will evaluate shell function calls that occur within an immedi- ate context. For instance: REQUIRED_DIRS = ... _MKDIRS := $(shell for d in $(REQUIRED_DIRS); \ do \ [[ -d $$d ]] || mkdir -p $$d; \ done) $(objects) : $(sources) As we’ve seen before, the purpose of the _MKDIRS simple variable is to trigger the cre- ation of essential directories. When this is executed with --just-print, the shell command will be executed as usual when the makefile is read. Then make will echo (without executing) each compilation command required to update the $(objects) file list. --print-data-base The --print-data-base (-p) option is another one you’ll use often. It executes the makefile, displaying the GNU copyright followed by the commands as they are run by make, then it will dump its internal database. The data is collected into groups of 230 | Chapter 12: Debugging Makefiles This is the Title of the Book, eMatter Edition Copyright © 2005 O’Reilly & Associates, Inc. All rights reserved. ,ch12.8053 Page 231 Friday, March 25, 2005 2:55 PM values: variables, directories, implicit rules, pattern-specific variables, files (explicit rules), and the vpath search path: # GNU Make 3.80 # Copyright (C) 2002 Free Software Foundation, Inc. # This is free software; see the source for copying conditions. # There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A # PARTICULAR PURPOSE. normal command execution occurs here # Make data base, printed on Thu Apr 29 20:58:13 2004 # Variables … # Directories … # Implicit Rules … # Pattern-specific variable values … # Files … # VPATH Search Paths Let’s examine these sections in more detail. The variables section lists each variable along with a descriptive comment: # automatic <D = $(patsubst %/,%,$(dir $<)) # environment EMACS_DIR = C:/usr/emacs-21.3.50.7 # default CWEAVE = cweave # makefile (from `../mp3_player/makefile', line 35) CPPFLAGS = $(addprefix -I ,$(include_dirs)) # makefile (from `../ch07-separate-binaries/makefile', line 44) RM := rm -f # makefile (from `../mp3_player/makefile', line 14) define make-library libraries += $1 sources += $2 $1: $(call source-to-object,$2) $(AR) $(ARFLAGS) $$@ $$^ endef Automatic variables are not printed, but convenience variables derived from them like $(<D) are. The comment indicates the type of the variable as returned by the origin function (see the section “Less Important Miscellaneous Functions” in Chapter 4). If the variable is defined in a file, the filename and line number of the definition is given. Simple and recursive variables are distinguished by the Debugging Features of make | 231 This is the Title of the Book, eMatter Edition Copyright © 2005 O’Reilly & Associates, Inc. All rights reserved. ,ch12.8053 Page 232 Friday, March 25, 2005 2:55 PM assignment operator. The value of a simple variable will be displayed as the evalu- ated form of the righthand side. The next section, labeled Directories, is more useful to make developers than to make users. It lists the directories being examined by make, including SCCS and RCS subdi- rectories that might exist, but usually do not. For each directory, make displays imple- mentation details, such as the device number, inode, and statistics on file pattern matches. The Implicit Rules section follows. This contains all the built-in and user-defined pattern rules in make’s database. Again, for those rules defined in a file, a comment indicates the file and line number: %.c %.h: %.y # commands to execute (from `../mp3_player/makefile', line 73): $(YACC.y) --defines $< $(MV) y.tab.c $*.c $(MV) y.tab.h $*.h %: %.c # commands to execute (built-in): $(LINK.c) $^ $(LOADLIBES) $(LDLIBS) -o $@ %.o: %.c # commands to execute (built-in): $(COMPILE.c) $(OUTPUT_OPTION) $< Examining this section is a great way to become familiar with the variety and struc- ture of make’s built-in rules. Of course, not all built-in rules are implemented as pat- tern rules. If you don’t find the rule you’re looking for, check in the Files section where the old-style suffix rules are listed. The next section catalogs the pattern-specific variables defined in the makefile. Recall that pattern-specific variables are variable definitions whose scope is precisely the execution time of their associated pattern rule. For example, the pattern variable YYLEXFLAG, defined as: %.c %.h: YYLEXFLAG := -d %.c %.h: %.y $(YACC.y) --defines $< $(MV) y.tab.c $*.c $(MV) y.tab.h $*.h would be displayed as: # Pattern-specific variable values %.c : # makefile (from `Makefile', line 1) # YYLEXFLAG := -d # variable set hash-table stats: # Load=1/16=6%, Rehash=0, Collisions=0/1=0% 232 | Chapter 12: Debugging Makefiles This is the Title of the Book, eMatter Edition Copyright © 2005 O’Reilly & Associates, Inc. All rights reserved. ,ch12.8053 Page 233 Friday, March 25, 2005 2:55 PM %.h : # makefile (from `Makefile', line 1) # YYLEXFLAG := -d # variable set hash-table stats: # Load=1/16=6%, Rehash=0, Collisions=0/1=0% # 2 pattern-specific variable values The Files section follows and lists all the explicit and suffix rules that relate to specific files: # Not a target: .p.o: # Implicit rule search has not been done. # Modification time never checked. # File has not been updated. # commands to execute (built-in): $(COMPILE.p) $(OUTPUT_OPTION) $< lib/ui/libui.a: lib/ui/ui.o # Implicit rule search has not been done. # Last modified 2004-04-01 22:04:09.515625 # File has been updated. # Successfully updated. # commands to execute (from `../mp3_player/lib/ui/module.mk', line 3): ar rv $@ $^ lib/codec/codec.o: ../mp3_player/lib/codec/codec.c ../mp3_player/lib/codec/codec.c .. /mp3_player/include/codec/codec.h # Implicit rule search has been done. # Implicit/static pattern stem: `lib/codec/codec' # Last modified 2004-04-01 22:04:08.40625 # File has been updated. # Successfully updated. # commands to execute (built-in): $(COMPILE.c) $(OUTPUT_OPTION) $< Intermediate files and suffix rules are labeled “Not a target”; the remainder are tar- gets. Each file includes comments indicating how make has processed the rule. Files that are found through the normal vpath search have their resolved path displayed. The last section is labeled VPATH Search Paths and lists the value of VPATH and all the vpath patterns. For makefiles that make extensive use of user-defined functions and eval to create complex variables and rules, examining this output is often the only way to verify that macro expansion has generated the expected values. --warn-undefined-variables This option causes make to display a warning whenever an undefined variable is expanded. Since undefined variables expand to the empty string, it is common for typographical errors in variable names to go undetected for long periods. The problem Debugging Features of make | 233 This is the Title of the Book, eMatter Edition Copyright © 2005 O’Reilly & Associates, Inc. All rights reserved. ,ch12.8053 Page 234 Friday, March 25, 2005 2:55 PM with this option, and why I use it only rarely, is that many built-in rules include unde- fined variables as hooks for user-defined values.
Recommended publications
  • 7843 Directory Management

    7843 Directory Management

    7843 Directory Management Tired of using existing badly written operating systems, Hieu decided to write his new one. Of course, his new operating system will be awesome, bug-free, fast and easy to use. He has finished most of the work, and now he is asking you to do one lasttask: Implement a directory manager. Initially, Hieu’s computer directory is empty. The current directory is the root directory. The directory manager keeps the directory in a rooted-tree structure. In each directory, the children are sorted in lexicographical order. He can do one of the following actions: • MKDIR s: create a child directory named s inside the current directory where s is a string. – If the current directory already contains a child directory named s, print “ERR” and do nothing. – Otherwise, print “OK” • RM s: remove a child directory named s inside the current directory where s is a string. Figure 1 – If there is no child directory named s, print “ERR”. Otherwise, print “OK”. • CD s: change the current directory to a child directory named s where s is a string. – If s is equal to the string “..” and the current directory is the root directory, print “ERR” and do nothing. – If s is equal to the string “..” and the current directory is not the root direc- tory, then you need to change the current directory to the parent directory Figure 2 and print “OK”. – If there is no child directory named s, print “ERR” and do nothing. – If there is a child directory named s then you need to change the current directory to s and print “OK”.
  • Print Wizard 3 Manual

    Print Wizard 3 Manual

    Print Wizard User Guide and Technical Manual Version 3.0 and later Rasmussen Software, Inc. 10240 SW Nimbus Ave., Suite L9, Portland, Oregon 97223 (503) 624-0360 www.anzio.com [email protected] Copyright © 2004-2005 by Rasmussen Software, Inc., All Rights Reserved Rasmussen Software, Inc. Page 1 Print Wizard Manual Table of Contents Table of Contents PRINT WIZARD USER GUIDE.......................................................................................................................................... 7 1 PRINT WIZARD INTRODUCTION ......................................................................................................................................... 7 1.1 What is Print Wizard?............................................................................................................................................... 7 1.2 Concept..................................................................................................................................................................... 7 1.3 Profiles and Services .............................................................................................................................................. 10 1.3.1 Introduction to print profiles................................................................................................................................................11 1.3.2 Introduction to services .......................................................................................................................................................12
  • Disk Clone Industrial

    Disk Clone Industrial

    Disk Clone Industrial USER MANUAL Ver. 1.0.0 Updated: 9 June 2020 | Contents | ii Contents Legal Statement............................................................................... 4 Introduction......................................................................................4 Cloning Data.................................................................................................................................... 4 Erasing Confidential Data..................................................................................................................5 Disk Clone Overview.......................................................................6 System Requirements....................................................................................................................... 7 Software Licensing........................................................................................................................... 7 Software Updates............................................................................................................................. 8 Getting Started.................................................................................9 Disk Clone Installation and Distribution.......................................................................................... 12 Launching and initial Configuration..................................................................................................12 Navigating Disk Clone.....................................................................................................................14
  • Tutorial for VCS

    Tutorial for VCS

    Tutorial for VCS STEP 1: login to the Linux system on Linuxlab server. Start a terminal (the shell prompt). Click here to open a shell window Fig. 1 The screen when you login to the Linuxlab through equeue STEP 2: In the terminal, execute the following command: module add ese461 You could perform “module avail” in the terminal to find the available modules on Linuxlab. Make sure ese461 is presented when you execute this command. 1.Find the available modules 2.Make sure ese461 is presented 3.This command will set up the work environment for class ESE461 Fig. 2 Build work environment for class ESE461 using module 1 STEP 3: Getting started with Verilog • Creating a new folder (better if you have all the files for a project in a specific folder). • Enter into this new folder and start writing your Verilog script in a new file (.v file). Example code for modeling an counter is here • In addition to model code, Test Bench script has to be given in order to verify the functionality of your model (.v file). Example code of test bench for counter is here. Use gedit to edit the .v files (gedit is a commonly used GUI editor on Linux ) Fig. 3 Open gedit through teminal STEP 4: Compiling and simulating your code • In the terminal, change the directory to where your model and test bench files (Counter.v and Counter_tb.v) are present by using this command: cd <path> For example: cd ~/ESE461/VcsTutorial/ (Remark: ‘~’ means home directory on Linux) • Compile the files by typing in the terminal: vcs <file>.v <file_tb>.v In the above example, it should be: vcs Counter.v Counter_tb.v There should be no error presented in the terminal.
  • Mac Keyboard Shortcuts Cut, Copy, Paste, and Other Common Shortcuts

    Mac Keyboard Shortcuts Cut, Copy, Paste, and Other Common Shortcuts

    Mac keyboard shortcuts By pressing a combination of keys, you can do things that normally need a mouse, trackpad, or other input device. To use a keyboard shortcut, hold down one or more modifier keys while pressing the last key of the shortcut. For example, to use the shortcut Command-C (copy), hold down Command, press C, then release both keys. Mac menus and keyboards often use symbols for certain keys, including the modifier keys: Command ⌘ Option ⌥ Caps Lock ⇪ Shift ⇧ Control ⌃ Fn If you're using a keyboard made for Windows PCs, use the Alt key instead of Option, and the Windows logo key instead of Command. Some Mac keyboards and shortcuts use special keys in the top row, which include icons for volume, display brightness, and other functions. Press the icon key to perform that function, or combine it with the Fn key to use it as an F1, F2, F3, or other standard function key. To learn more shortcuts, check the menus of the app you're using. Every app can have its own shortcuts, and shortcuts that work in one app may not work in another. Cut, copy, paste, and other common shortcuts Shortcut Description Command-X Cut: Remove the selected item and copy it to the Clipboard. Command-C Copy the selected item to the Clipboard. This also works for files in the Finder. Command-V Paste the contents of the Clipboard into the current document or app. This also works for files in the Finder. Command-Z Undo the previous command. You can then press Command-Shift-Z to Redo, reversing the undo command.
  • Powerview Command Reference

    Powerview Command Reference

    PowerView Command Reference TRACE32 Online Help TRACE32 Directory TRACE32 Index TRACE32 Documents ...................................................................................................................... PowerView User Interface ............................................................................................................ PowerView Command Reference .............................................................................................1 History ...................................................................................................................................... 12 ABORT ...................................................................................................................................... 13 ABORT Abort driver program 13 AREA ........................................................................................................................................ 14 AREA Message windows 14 AREA.CLEAR Clear area 15 AREA.CLOSE Close output file 15 AREA.Create Create or modify message area 16 AREA.Delete Delete message area 17 AREA.List Display a detailed list off all message areas 18 AREA.OPEN Open output file 20 AREA.PIPE Redirect area to stdout 21 AREA.RESet Reset areas 21 AREA.SAVE Save AREA window contents to file 21 AREA.Select Select area 22 AREA.STDERR Redirect area to stderr 23 AREA.STDOUT Redirect area to stdout 23 AREA.view Display message area in AREA window 24 AutoSTOre ..............................................................................................................................
  • JAMS 7.X User Guide

    JAMS 7.X User Guide

    User Guide JAMS Scheduler 7.3 Copyright Terms and Conditions Copyright Help/Systems LLC and its group of companies. The content in this document is protected by the Copyright Laws of the United States of America and other countries worldwide. The unauthorized use and/or duplication of this material without express and written permission from HelpSystems is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to HelpSystems with appropriate and specific direction to the original content. HelpSystems and its trademarks are properties of the HelpSystems group of companies. All other marks are property of their respective owners. 202108110755 JAMS 7.X User Guide Table of Contents JAMS 7.X Client Features 3 Jobs In JAMS 4 Working with Jobs 5-19 Scheduling Recurring Jobs 20-22 Execution Methods 23-27 Submitting Jobs Manually 28-29 Sequence Jobs 30-34 Managing Sequence Parameters 35-38 Sequence Tasks 39-47 Workflow Jobs 48-51 Workflow Activities 52-59 Migrating JAMS Objects 60-61 File Transfer Features 62-67 Variables 68 Working with Variables 69-71 Elements 72 Documentation Elements 73-74 EventHandler Elements 75-79 Prerequisite Elements 80-83 Result Elements 84-86 Trigger Elements 87-92 Folders 93 Working with Folders 94-104 Dates and Times 105 Date Properties 106-107 Creating Special Date Definitions 108-111 Specifying Dates Using Natural Language 112-114 Named Times in JAMS 115-118 Dashboards and Reports 119 Custom Dashboards 120-129 Creating New Report Templates and Customizing Existing Reports
  • Project1: Build a Small Scanner/Parser

    Project1: Build a Small Scanner/Parser

    Project1: Build A Small Scanner/Parser Introducing Lex, Yacc, and POET cs5363 1 Project1: Building A Scanner/Parser Parse a subset of the C language Support two types of atomic values: int float Support one type of compound values: arrays Support a basic set of language concepts Variable declarations (int, float, and array variables) Expressions (arithmetic and boolean operations) Statements (assignments, conditionals, and loops) You can choose a different but equivalent language Need to make your own test cases Options of implementation (links available at class web site) Manual in C/C++/Java (or whatever other lang.) Lex and Yacc (together with C/C++) POET: a scripting compiler writing language Or any other approach you choose --- must document how to download/use any tools involved cs5363 2 This is just starting… There will be two other sub-projects Type checking Check the types of expressions in the input program Optimization/analysis/translation Do something with the input code, output the result The starting project is important because it determines which language you can use for the other projects Lex+Yacc ===> can work only with C/C++ POET ==> work with POET Manual ==> stick to whatever language you pick This class: introduce Lex/Yacc/POET to you cs5363 3 Using Lex to build scanners lex.yy.c MyLex.l lex/flex lex.yy.c a.out gcc/cc Input stream a.out tokens Write a lex specification Save it in a file (MyLex.l) Compile the lex specification file by invoking lex/flex lex MyLex.l A lex.yy.c file is generated
  • GNU M4, Version 1.4.7 a Powerful Macro Processor Edition 1.4.7, 23 September 2006

    GNU M4, Version 1.4.7 a Powerful Macro Processor Edition 1.4.7, 23 September 2006

    GNU M4, version 1.4.7 A powerful macro processor Edition 1.4.7, 23 September 2006 by Ren´eSeindal This manual is for GNU M4 (version 1.4.7, 23 September 2006), a package containing an implementation of the m4 macro language. Copyright c 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.” i Table of Contents 1 Introduction and preliminaries ................ 3 1.1 Introduction to m4 ............................................. 3 1.2 Historical references ............................................ 3 1.3 Invoking m4 .................................................... 4 1.4 Problems and bugs ............................................. 8 1.5 Using this manual .............................................. 8 2 Lexical and syntactic conventions ............ 11 2.1 Macro names ................................................. 11 2.2 Quoting input to m4........................................... 11 2.3 Comments in m4 input ........................................ 11 2.4 Other kinds of input tokens ................................... 12 2.5 How m4 copies input to output ................................ 12 3 How to invoke macros........................
  • GNU M4, Version 1.4.19 a Powerful Macro Processor Edition 1.4.19, 28 May 2021

    GNU M4, Version 1.4.19 a Powerful Macro Processor Edition 1.4.19, 28 May 2021

    GNU M4, version 1.4.19 A powerful macro processor Edition 1.4.19, 28 May 2021 by Ren´eSeindal, Fran¸coisPinard, Gary V. Vaughan, and Eric Blake ([email protected]) This manual (28 May 2021) is for GNU M4 (version 1.4.19), a package containing an implementation of the m4 macro language. Copyright c 1989{1994, 2004{2014, 2016{2017, 2020{2021 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled \GNU Free Documentation License." i Table of Contents 1 Introduction and preliminaries ::::::::::::::::: 3 1.1 Introduction to m4 :::::::::::::::::::::::::::::::::::::::::::::: 3 1.2 Historical references :::::::::::::::::::::::::::::::::::::::::::: 3 1.3 Problems and bugs ::::::::::::::::::::::::::::::::::::::::::::: 4 1.4 Using this manual :::::::::::::::::::::::::::::::::::::::::::::: 5 2 Invoking m4::::::::::::::::::::::::::::::::::::::: 7 2.1 Command line options for operation modes ::::::::::::::::::::: 7 2.2 Command line options for preprocessor features ::::::::::::::::: 8 2.3 Command line options for limits control ::::::::::::::::::::::: 10 2.4 Command line options for frozen state ::::::::::::::::::::::::: 11 2.5 Command line options for debugging :::::::::::::::::::::::::: 11 2.6 Specifying input files on the command line :::::::::::::::::::::
  • An AWK to C++ Translator

    An AWK to C++ Translator

    An AWK to C++ Translator Brian W. Kernighan Bell Laboratories Murray Hill, NJ 07974 [email protected] ABSTRACT This paper describes an experiment to produce an AWK to C++ translator and an AWK class definition and supporting library. The intent is to generate efficient and read- able C++, so that the generated code will run faster than interpreted AWK and can also be modified and extended where an AWK program could not be. The AWK class and library can also be used independently of the translator to access AWK facilities from C++ pro- grams. 1. Introduction An AWK program [1] is a sequence of pattern-action statements: pattern { action } pattern { action } ... A pattern is a regular expression, numeric expression, string expression, or combination of these; an action is executable code similar to C. The operation of an AWK program is for each input line for each pattern if the pattern matches the input line do the action Variables in an AWK program contain string or numeric values or both according to context; there are built- in variables for useful values such as the input filename and record number. Operators work on strings or numbers, coercing the types of their operands as necessary. Arrays have arbitrary subscripts (‘‘associative arrays’’). Input is read and input lines are split into fields, called $1, $2, etc. Control flow statements are like those of C: if-else, while, for, do. There are user-defined and built-in functions for arithmetic, string, regular expression pattern-matching, and input and output to/from arbitrary files and processes.
  • Toolkit Feature Interactive Debug Facility User's Guide

    Toolkit Feature Interactive Debug Facility User's Guide

    High Level Assembler for z/OS & z/VM & z/VSE IBM Toolkit Feature Interactive Debug Facility User's Guide Version 1 Release 6 GC26-8709-09 High Level Assembler for z/OS & z/VM & z/VSE IBM Toolkit Feature Interactive Debug Facility User's Guide Version 1 Release 6 GC26-8709-09 Note Before using this information and the product it supports, be sure to read the general information under “Notices” on page 311. This edition applies to IBM High Level Assembler for z/OS & z/VM & z/VSE Toolkit Feature, Release 6, Program Number 5696-234 and to any subsequent releases until otherwise indicated in new editions. Make sure that you are using the correct edition for the level of the product. Order publications through your IBM representative or the IBM branch office serving your locality. IBM welcomes your comments. For information on how to send comments, see “How to send your comments to IBM” on page xv. © Copyright IBM Corporation 1992, 2017. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Figures ............... ix Building a module on z/OS ........ 17 Building a module on CMS ........ 17 About this book ........... xi Building a phase on z/VSE ........ 17 Running ASMLANGX ........... 18 Syntax notation ............. xi Extraction file allocation on z/OS ...... 18 Online language extraction on TSO ..... 19 How to send your comments to IBM .. xv Batch language extraction on z/OS ..... 19 If you have a technical problem ....... xv Online language extraction on CMS ..... 20 Batch language extraction on z/VSE ....