M Programmer's Guide

Welcome to The M Programmer's Guide!

Main YottaDB Documentation Page
About this Manual
- Intended Audience
- Purpose of the Manual
- How to use this Manual
1. About YottaDB
- Programming Environment
2. YottaDB Language Extensions
- Operating System Interface Facilities
- Debugging Facilities
- Exception Handling Facilities
- Interrupting Execution Flow
- Journaling Extensions
- Extensions for Additional Capability
- Device Handling Extensions
- Alias Variable Extensions
- Extensions for Unicode® standard support
3. Development Cycle
- Overview of the Program Development Cycle
- Defining Environment Variables
- Preparing the Database
- Creating and Editing a Source Program
  - Editing from YottaDB
  - Editing from the Shell
- Compiling a Source Program
- Executing a Source Program
  - Executing in the Direct Mode
  - Locating the Source File Directory
- Executing from the Shell
- Processing Errors from Direct Mode and Shell
4. Operating and Debugging in Direct Mode
- Operating in Direct Mode
- Debugging a Routine in Direct Mode
- Summary of Debugging Tools
5. General Language Features of M
- Data Types
- M Names
- Variables
- Literals
  - String Literals
  - Numeric Literals
- Expressions
- Operators
- Commands
- M Locks
- Intrinsic Functions
- Intrinsic Special Variables
- Routines
- Indirection
- Parameter Passing
- External Calls
- Extrinsic Functions
- Extrinsic Special Variables
- Transaction Processing
6. Commands
- Break
  - Examples of BREAK
- Close
- Do
  - Examples of DO
- Else
  - Examples of ELSE
- For
  - Examples of FOR
- Goto
  - Examples of GOTO
- HALT
- HANG
  - Examples of HANG
- If
  - Examples of IF
- Job
  - The JOB Environment
    - JOB Implications for Directories
  - JOB processparameters
  - Examples of JOB
- Kill
  - Examples of KILL
- Lock
  - Deadlock Situation
  - Using Locks within Transactions
    - Lock Command Operation Summary
  - Examples of LOCK
- Merge
  - Examples of MERGE
- New
  - Examples of NEW
- Open
- Quit
  - Examples of Quit
- READ
- Set
  - Examples of SET
- TCommit
- TREstart
- TROllback
- TStart
  - S[ERIAL]
  - T[RANSACTIONID]=expr
- Use
- View
  - Keywords in VIEW Command
  - Examples of VIEW
- Write
- Xecute
  - Examples of XECUTE
- ZAllocate
  - Examples of ZALLOCATE
    - Deadlock Situation
  - ZAllocate Operation Summary
- ZBREAK
  - Examples of ZBREAK
- ZCOMpile
  - Examples of ZCOMPILE
- ZContinue
- ZDeallocate
  - Examples of ZDEALLOCATE
- ZEdit
  - Examples of ZEDIT
- ZGoto
  - Examples of ZGOTO
- ZHALT
  - Examples of ZHALT
- ZHelp
  - Examples of ZHELP
- ZKill
- ZLink
  - ZLink Operation Summary
  - ZLINK Compilation
  - Examples of ZLINK
  - Auto ZLINK
  - ZLINK, auto-ZLINK and Routine Names
  - Auto-Relink Setup
    - Auto-Relink Benefits and Example
- ZMessage
  - Examples of ZMESSAGE
- ZPrint
  - Examples of ZPRINT
- ZRUPdate
- ZSHow
  - ZSHOW Information Codes
  - Examples of ZSHOW
  - ZSHOW Destination Variables
  - Use of ZSHOW
- ZSTep
  - ZSTEP INTO
  - ZSTEP OUtof
  - ZSTep OVer
  - ZStep Actions
  - ZStep Interactions
  - Use of ZSTEP
  - Examples of ZSTEP
- ZSYstem
  - Examples of ZSYSTEM
- ZTCommit
  - Examples of ZTCOMMIT
- ZTRigger
- ZTStart
- ZWIthdraw
  - Examples of ZWITHDRAW
- ZWRite
  - ZWRITE Format for Alias Variables
  - Examples of ZWRITE
7. Functions
- $ASCII()
  - Examples of $ASCII()
- $CHAR()
  - Examples of $CHAR()
- $DATA()
  - $DATA() Results
  - Examples of $DATA()
- $EXTRACT()
  - Examples of $EXTRACT()
- $FIND()
  - Examples of $FIND()
- $FNUMBER()
  - Examples of $FNUMBER()
- $GET()
  - Examples of $GET()
- $INCREMENT()
  - Examples of $INCREMENT()
- $JUSTIFY()
  - Examples of $JUSTIFY()
- $LENGTH()
  - Examples of $LENGTH()
- $NAME()
  - Examples of $NAME()
- $NEXT()
- $ORDER()
  - Examples of $ORDER()
- $PIECE()
  - Examples of $PIECE()
- $QLENGTH()
  - Examples of $QLENGTH()
- $QSUBSCRIPT()
  - Examples of $QSUBSCRIPT()
- $QUERY()
  - Examples of $QUERY()
- $RANDOM()
  - Examples of $RANDOM()
- $REVERSE()
  - Examples of $REVERSE()
- $SELECT()
  - Examples of $SELECT()
- $STACK()
  - Examples of $STACK()
- $TEXT()
  - Examples of $TEXT()
- $TRANSLATE()
  - Examples of $TRANSLATE()
- $VIEW()
  - Argument Keywords of $VIEW()
  - Examples of $VIEW()
- $ZAHANDLE()
  - Examples of $ZAHANDLE()
- $ZASCII()
  - Examples of $ZASCII()
- $ZATRANSFORM()
  - Examples of $ZATRANSFORM()
- $ZAUditlog()
  - Examples of $ZAUDITLOG()
- $ZBIT Functions
  - $ZBITAND()
  - $ZBITCOUNT()
  - $ZBITFIND()
  - $ZBITGET()
  - $ZBITLEN()
  - $ZBITNOT()
  - $ZBITOR()
  - $ZBITSET()
  - $ZBITSTR()
  - $ZBITXOR()
  - Examples of $ZBIT Functions
- $ZCHAR()
  - Example of $ZCHAR()
- $ZCOLLATE()
  - Examples of $ZCOLLATE()
- $ZCONVERT()
  - Examples of $ZCONVERT()
- $ZDATA()
  - Examples of $ZDATA()
- $ZDATE()
  - $ZDATE() Format Specification Elements
  - Examples of $ZDATE()
- $ZEXTRACT()
  - Examples of $ZEXTRACT()
- $ZFIND()
  - Examples of $ZFIND()
- $ZGETJPI()
  - Examples of $ZGETJPI()
- $ZJOBEXAM()
  - Examples of $ZJOBEXAM()
- $ZJUSTIFY()
  - Examples of $ZJUSTIFY()
- $ZLENGTH()
  - Examples of $ZLENGTH()
- $ZMESSAGE()
  - Examples of $ZMESSAGE()
- $ZPARSE()
  - Examples of $ZPARSE()
- $ZPEEK()
- $ZPIECE()
  - Examples of $ZPIECE()
- $ZPREVIOUS()
- $ZQGBLMOD()
- $ZSEARCH()
  - Examples of $ZSEARCH()
- $ZSIGPROC()
  - Examples of $ZSIGPROC()
- $ZSOCKET()
- $ZSUBSTR()
  - Examples of $ZSUBSTR()
- $ZSYSLOG()
- $ZTRANSLATE()
  - Examples of $ZTRANSLATE()
- $ZTRIGGER()
  - Examples of $ZTRIGGER()
- $ZTRNLNM()
  - Examples of $ZTRNLNM()
- $ZWIDTH()
  - Examples of $ZWIDTH()
- $ZWRITE()
  - Examples of $ZWRITE()
- $ZYHASH()
  - Examples of $ZYHASH()
- $ZYISSQLNULL()
  - Examples of $ZYISSQLNULL()
- $ZYSUFFIX()
  - Examples of $ZYSUFFIX()
8. Intrinsic Special Variables
- $DEVICE
- $ECODE
- $ESTACK
- $ETRAP
- $HOROLOG
- $IO
- $JOB
- $KEY
- $PRINCIPAL
- $QUIT
- $REFERENCE
- $STACK
- $STORAGE
- $SYSTEM
- $TEST
- $TLEVEL
- $TRESTART
- $X
- $Y
- $ZA
- $ZALLOCSTOR
- $ZAUDIT
- $ZB
- $ZCHSET
- $ZCLOSE
- $ZCMDLINE
- $ZCOMPILE
- $ZCSTATUS
- $ZDATEFORM
- $ZDIRECTORY
- $ZEDITOR
- $ZEOF
- $ZERROR
- $ZGBLDIR
- $ZHOROLOG
- $ZININTERRUPT
- $ZINTERRUPT
- $ZIO
- $ZJOB
- $ZKEY
- $ZLEVEL
- $ZMALLOCLIM
- $ZMAXTPTIME
- $ZMODE
- $ZONLNRLBK
- $ZPATNUMERIC
- $ZPIN
- $ZPOSITION
- $ZPOUT
- $ZPROMPT
- $ZQUIT
- $ZREALSTOR
- $ZRELDATE
- $ZROUTINES
  - Establishing the value from $ydb_routines
  - Setting a Value for $ZROUTINES
  - $ZROUTINES Examples
  - $ZROUTINES Search Types
  - $ZROUTINES Search Examples
  - Shared Library File Specification in $ZROUTINES
- $ZSOURCE
- $ZSTATUS
- $ZSTEP
- $ZSTRPLLIM
- $ZSYSTEM
- $ZTEXIT
- $ZTIMEOUT
- $ZTRAP
- $ZUSEDSTOR
- $ZUT
- $ZVERSION
- $ZYERROR
- $ZYINTRSIG
- $ZYRELEASE
- $ZYSQLNULL
- Trigger ISVs
  - $ZTDATA
  - $ZTDELIM
  - $ZTLEVEL
  - $ZTNAME
  - $ZTOLDVAL
  - $ZTRIGGEROP
  - $ZTSLATE
  - $ZTUPDATE
  - $ZTVALUE
  - $ZTWORMHOLE
9. Input/Output Processing
- I/O Intrinsic Special Variables
  - Device Name Variables
    - $IO
    - $PRINCIPAL
    - $ZIO
    - $ZPIN
    - $ZPOUT
  - Cursor Position Variables
  - Status Variables
    - $DEVICE
    - $KEY
    - $ZA
    - $ZB
    - $ZEOF
- I/O Devices
- Using Terminals
- Using Sequential Files
- FIFO Characteristics
- Using NULL Devices
  - NULL Deviceparameter Summary
  - NULL Device Examples
- Using PIPE Devices
- Using Socket Devices
- I/O Commands
  - Open
    - APPEND
    - ATTACH
    - CHSET
    - COMMAND
    - CONNECT
    - DELIMITER
    - EXCEPTION
    - EMPTERM
    - FFLF
    - FIFO
    - FIXED
    - FOLLOW
    - GROUP
    - ICHSET
    - INDEPENDENT
    - IKEY
    - IOERROR
    - KEY
    - LISTEN
    - MOREREADTIME
    - NEWVERSION
    - OCHSET
    - OKEY
    - OWNER
    - OPTIONS
    - PAD
    - PARSE
    - READONLY
    - RECORDSIZE
    - REWIND
    - SEEK=strexpr
    - SHELL
    - STDERR
    - STREAM
    - TRUNCATE
    - UIC
    - VARIABLE
    - WORLD
    - WRAP
    - WRITEONLY
    - ZBFSIZE
    - ZDELAY
    - ZFF
    - ZIBFSIZE
  - USE
    - ATTACH
    - CANONICAL
    - CENABLE
    - CLEARSCREEN
    - CONNECT
    - CONVERT
    - CTRAP
    - DELIMITER
    - DETACH
    - DOWNSCROLL
    - ECHO
    - EDITING
    - EMPTERM
    - ERASELINE
    - ESCAPE
    - EXCEPTION
    - FFLF
    - FILTER
    - FOLLOW
    - HOSTSYNC
    - HUPENABLE
    - IKEY
    - INREWIND
    - INSEEK=strexpr
    - INSERT
    - IOERROR
    - KEY
    - LENGTH
    - OKEY
    - OPTIONS
    - OUTREWIND
    - OUTSEEK=strexpr
    - PASTHRU
    - READSYNC
    - REWIND
    - SEEK=strexpr
    - SOCKET
    - TERMINATOR
    - TRUNCATE
    - TTSYNC
    - TYPEAHEAD
    - UPSCROLL
    - WIDTH
    - WRAP
    - X
    - Y
    - ZBFSIZE
    - ZDELAY
    - ZFF
    - ZIBFSIZE
  - READ
    - READ * Command
    - Read X#maxlen command
  - WRITE
  - WRITE *
  - CLOSE
    - DELETE
    - DESTROY
    - EXCEPTION
    - GROUP
    - OWNER
    - RENAME
    - REPLACE
    - SOCKET
    - TIMEOUT
    - UIC
    - WORLD
  - Deviceparameter Summary Table
10. Utility Routines
- Using the Utilities
- Date and Time Utilities
  - %D
  - %DATE
  - %H
  - %T
  - %TI
  - %TO
- Conversion Utilities
  - %DH
  - %DO
  - %HD
  - %HO
  - %JSWRITE
  - %LCASE
  - %OD
  - %OH
  - %UCASE
- Mathematic Utilities
  - %EXP
  - %SQROOT
- String Utilities
  - %MPIECE
  - %RANDSTR
  - %TRIM
- Global Utilities
  - %G
  - %GC
  - %GCE
  - %GD
  - %GED
  - %GI
  - %GO
  - %GSE
  - %GSEL
  - %ZSHOWVTOLCL
- Routine Utilities
  - %FL
  - %RCE
  - %RD
  - %RI
  - %RO
  - %RSE
  - %RSEL
- Internationalization Utilities
- System Management Utilities
- UTF-8 Mode Utility Routines
  - %UTF2HEX
  - %HEX2UTF
- Miscellaneous utilities
  - %ZMVALID
- Utilities Summary Table
11. Integrating External Routines
- Introduction
- Access to non-M Routines
- Creating a Shareable Library
- Using External Calls: Call-Outs
- Calls from External Routines: Call-Ins
- Type Limits for Call-Ins and Call-Outs
- Error cases for ydb_buffer_t*
- Choosing the right parameter type for strings
12. Internationalization
- Collation Sequence Definitions
- Creating the Alternate Collation Routines
- Implementing an Alternative Collation Sequence for Unicode® Characters
- Matching Alternative Patterns
  - Pattern Code Definition
  - Pattern Code Selection
13. Error Processing
- Compile Time Error Message Format
- Processing Compile Time Errors
- Run Time Error Message Format
- Processing Run-Time Errors
  - Run-Time Errors in Direct Mode
  - Run-Time Errors Outside of Direct Mode
- Program Handling of Errors
- Error Actions
14. Triggers
- Triggers
- Trigger Definition File
- Trigger ISVs Summary
- Chained and Nested Triggers
- A Simple Example
- Trigger Definition Storage
- Trigger Invocation and Execution Semantics
- Triggers in Journaling and Database Replication
  - Journaling
  - Multisite Database Replication
- MUPIP Trigger and $ZTRIGGER()
15. Database Encryption Extensions to the YottaDB External Interface
Appendix A: M Coding Standards - Do's and Don'ts
- M Coding Standards - Do's and Don'ts
  - Do's
  - Don'ts
Appendix B: Creating Shebang Scripts
LICENSE

Indices and tables