--- freem/doc/freem.texi 2025/04/28 14:52:54 1.34 +++ freem/doc/freem.texi 2025/05/02 15:16:36 1.37 @@ -4,7 +4,8 @@ @settitle The FreeM Manual @copying -This manual is for FreeM, (version 0.64.0-rc1), which is a free and open-source implementation of the M programming language. +This manual is for FreeM, (version 0.64.0-rc1), which is a free software@footnote{FreeM subscribes to the software licensing philosophy described in @emph{Free Software, Free Society: +Selected Essays of Richard M. Stallman}.} implementation of the M programming language. Copyright @copyright{} 2014-2025 Coherent Logic Development LLC @@ -42,9 +43,11 @@ This is the official manual for the Free @menu * Introduction:: About the FreeM Project, its history, and its goals. +* Document Conventions:: Conventions used in this manual. * FreeM Invocation:: How to invoke FreeM from the command line. * The FreeM Environment Daemon:: Managing shared resources in the FreeM environment. * The FreeM Direct-Mode Environment:: Executing M programs interactively. +* Debugging:: The program development cycle of FreeM. * Directives:: Per-Routine Language Directives. * Intrinsic Special Variables:: Intrinsic Special Variables. @@ -91,7 +94,6 @@ This is the official manual for the Free * Interrupt Handling:: How FreeM handles interrupts. * Error Processing:: How to handle errors in M program code. * FreeM Error Codes:: Explanations of each FreeM error code. -* Debugging:: The program development cycle of FreeM. * System Configuration:: Configuring your FreeM installation. * Accessing FreeM from C Programs:: How to use the mlib interface. @@ -109,11 +111,11 @@ This is the official manual for the Free @node Introduction @unnumbered Introduction -FreeM started its life as @emph{FreeMUMPS}, written for MS-DOS and ported to SCO UNIX by a mysterious individual going by the name of "Shalom ha-Ashkenaz". It was released to MUG Deutschland in 1998. In 1999, Ronald L. Fox ported FreeM to the Red Hat Linux 5 of the GNU/Linux operating system. Thereafter, maintenance was taken over by the Generic Universal M Project, which changed its name first to Public Standard MUMPS and then by popular request to FreeM. +FreeM started its life as @emph{FreeMUMPS}, written for MS-DOS and ported to SCO UNIX by a mysterious individual going by the name of "Shalom ha-Ashkenaz". It was released to MUG Deutschland in 1998. In 1999, Ronald L. Fox ported FreeM to the Red Hat Linux 5 distribution of the GNU/Linux operating system. Thereafter, maintenance was taken over by the Generic Universal M Project, which changed its name first to Public Standard MUMPS and then by popular request to FreeM. When GT.M was open-sourced in late 1999, FreeM and GUMP were essentially abandoned. L.D. Landis, the owner of the original GUMP SourceForge project, and one of FreeM's significant contributors, passed maintenance of FreeM and ownership of its SourceForge project to Serena Willis in 2014. At this point, FreeM would not compile or run on modern Linux systems, so steps were taken to remedy the most pressing issues in the codebase. Limitations on the terminal size (previously hard-coded to 80x25) were lifted, and new @code{$VIEW} functions were added to retrieve the terminal size information. @code{$X} and @code{$Y} intrinsic special variables were updated to support arbitrary terminal sizes, and FreeM was once again able to build and run. -In February of 2020, work began in earnest to build a development and support infrastructure for FreeM and begin the careful process of refining it into a more stable and robust product. +In February of 2020, work began in earnest to build a development and support infrastructure for FreeM and begin the careful process of refining it into a more stable and robust application. @section Production Readiness @@ -224,6 +226,56 @@ Serena Willis (Current Maintainer and Pr Steve Zeck (Code) @end itemize + +@node Document Conventions +@chapter Document Conventions +@cindex document conventions +@cindex conventions + +@section Formatting Conventions + +This manual uses the following formatting conventions: +@itemize +@item Code examples, filesystem paths, and commands are presented in @code{monospace} +@item Placeholders where the reader is expected to supply a replacement value are presented in @code{@emph{monospace italics}}, and depending on context, may be surrounded by angle brackets +@item New terminology is introduced in @emph{proportional italics} +@end itemize + +@section Definitions + +FreeM uses abbreviations for common language elements: + +@table @asis +@item @emph{$PREFIX} +Refers to the base filesystem location within which FreeM is installed. For most distribution methods of FreeM, @emph{$PREFIX} represents either @code{/} or @code{/usr/local}. +@item @emph{dlabel} +Refers to a label in an M routine, beginning in the first column of the line. Can be a @emph{name} or an @emph{intlit}. +@item @emph{entryref} +Refers to an M routine entry point, denoted in the format @code{@emph{dlabel} [+@emph{intexpr}][^@emph{routine}]}. +@item @emph{expr} +Refers to any expression. Often presented in the format @emph{expr V }, where @emph{V} means @emph{giving}; e.g., @emph{expr V lvn} means @emph{expression giving local variable name}. +@item @emph{glvn} +Refers to the name of an M global, local, or structured system variable. +@item @emph{gvn} +Refers to the name of an M global variable. +@item @emph{intexpr} +Refers to an integer expression. +@item @emph{intlit} +Refers to an integer literal. +@item @emph{ISV}, @emph{isv} +Refers to an M intrinsic special variable; @code{$JOB} and @code{$IO} are examples of ISVs. +@item @emph{L} +Indicates a @emph{list} of the following item, e.g., @emph{L gvn} means @emph{list of global variable names}. +@item @emph{lvn} +Refers to the name of an M local variable. +@item @emph{strlit} +Refers to an M string literal. +@item @emph{ssvn} +Refers to the name of an M structured system variable. +@item @emph{tvexpr} +Refers to a truth-valued expression. +@end table + @node FreeM Invocation @chapter FreeM Invocation @cindex invocation, command-line @@ -240,7 +292,7 @@ When @code{-r} or @code{--routine} are p @section %SYSINIT Routine -The @code{%SYSINIT} routine runs every time a FreeM interpreter process starts. This routine defines some useful constants, enables handling of @code{TRIGGER} events, and handles the execution of code passed via the @code{-x\--execute} or routines passed via @code{-r|--routine}. +The @code{%SYSINIT} routine runs every time a FreeM interpreter process starts. This routine defines some useful constants, enables handling of @code{TRIGGER} events, and handles the execution of code passed via the @code{-x|--execute} or routines passed via @code{-r|--routine}. Do not modify the supplied @code{%SYSINIT} routine to add site-specific startup items. Instead, create a @code{LCLINIT} routine in the @code{USER} namespace of one or more environments. @code{%SYSINIT} will automatically run @code{LCLINIT} each time it starts. @@ -522,6 +574,43 @@ DEFAULT.USER> Such expressions will be immediately evaluated, and the result printed on @code{@ref{$IO}}. +@node Debugging +@chapter Debugging +@cindex debugging + +@section Debugging Synopsis +FreeM includes an interactive debugger, entered using the @code{BREAK "DEBUG"} command. The debugger is also entered if @code{Ctrl-C} is pressed, @code{Ctrl-C} handling is enabled, and you are in direct mode. + +If you would like to enter the debugger automatically each time an error is encountered, add the following to your @code{LCLINIT} routine: + +@example +S $ETR="B ""DEBUG""" +@end example + +@section Debugging Commands +The debugger uses its own unique command language, where M commands are unavailable. Commands are as follows: + +@table @asis +@item @code{exit}, @code{quit} +Exits the debugger and returns to direct mode or normal program execution. +@item @code{e} @emph{glvn}, @code{examine} @emph{glvn} +Prints the value of @emph{glvn} to the terminal. +@item @code{t}, @code{trace} +Toggles @emph{trace mode} on and off. When trace mode is on, FreeM will display information about each @code{DO} or @code{GOTO} command encountered, including the routine which invoked the branch, which type of branch was invoked, and the target of the branch. +@item @code{s}, @code{step} +Single-steps through FreeM code command-by-command. +@item @code{n}, @code{next} +Single-steps through FreeM code line-by-line. +@item @code{c}, @code{cont}, @code{continue} +Resumes normal program execution, disabling single-step mode. +@item @code{bt}, @code{backtrace} +Produces a stack trace. +@item @code{h}, @code{halt} +Halts the process being debugged and returns control to the operating system. +@item @code{w [[+|-|?]@emph{}]}, @code{watch [[+|-|?]@emph{}]} +With no arguments, toggles watchpoints on and off. With @code{+}, adds @emph{} to the watchlist. With @code{-}, removes @emph{} from the watchlist. With @code{?}, queries the watch status of @emph{}. +@end table + @node Directives @chapter Directives @cindex directives @@ -2215,10 +2304,12 @@ In its argumentless form, @code{BREAK} s @emph{FreeM Extension} -In its single-argument form, @code{BREAK} sets @emph{Ctrl-C} handling and error handling characteristics, provided the optional @emph{postcondition} is @emph{true} or omitted. +In its single-argument form, @code{BREAK} enters the interactive debugger or sets @emph{Ctrl-C} handling and error handling characteristics, provided the optional @emph{postcondition} is @emph{true} or omitted. The following table enumerates the possible values of @emph{breakflag} @table @code +@item "DEBUG" +Enters the interactive debugger @item 0 Disables @emph{Ctrl-C} handling @item -2 @@ -2280,6 +2371,14 @@ In its inclusive form, transfers program DO[@emph{:postcondition}] @emph{entryref}[@emph{:postcondition}[,...]] @end example +@cartouche +@quotation +@emph{Non-Standard Behavior} + +FreeM allows @code{DO} @emph{entryref}s to follow the format of @code{+@emph{intexpr}}. In this case, the value of @emph{intexpr} will be interpreted as an offset from the first line of the current routine. +@end quotation +@end cartouche + In its argumentless form, transfers control to the following block of code where the line level is one greater than the level at which @code{DO} was encountered, provided the optional @emph{postcondition} evaluates to @emph{true} or is omitted. @emph{Syntax} @@ -2307,7 +2406,7 @@ ELSE[@emph{:postcondition}] FreeM allows a @emph{postcondition} on @code{ELSE}. While explicitly forbidden in the @emph{standard}--and for good reason--it was decided that FreeM should allow postconditions everywhere, both for the sake of foolish consistency (the likes of which Emerson warned against), and for the benefit of entrants to a hypothetical future obfuscated M contest, and those with a Machiavellian predisposition to wicked perversions and undue cleverness. -Using postconditions on @code{ELSE} should be strictly avoided in production code, as they have no practical use, and may contribute to technical debt, hardening of the arteries, hobgoblins, a small mind, a surfeit of logic, climate change, Daily WTF rants, or meltdown of global financial markets. +Using postconditions on @code{ELSE} should be strictly avoided in production code, as they have no practical use, and may contribute to technical debt, hardening of the arteries, hobgoblins, a small mind, a surfeit of logic, climate change, @emph{Daily WTF} rants, or the meltdown of global financial markets. @end quotation @end cartouche @@ -2403,6 +2502,15 @@ Transfers program execution to another l GOTO[@emph{:postcondition}] @emph{entryref} @end example +@cartouche +@quotation +@emph{Non-Standard Behavior} + +FreeM allows @code{GOTO} @emph{entryref}s to follow the format of @code{+@emph{intexpr}}. In this case, the value of @emph{intexpr} will be interpreted as an offset from the first line of the current routine. +@end quotation +@end cartouche + + @node HALT @section HALT @cindex HALT @@ -4411,7 +4519,30 @@ A @code{REAL} is a numeric interpretatio @cindex data types, STRING @cindex types, STRING -A @code{STRING} is any data in FreeM. +The @code{STRING} is the fundamental FreeM data type. Other types are inferred from the context of their usage. + +@subsection String Rules + +The following rules apply to all FreeM strings: + +@itemize +@item Must not exceed 255 characters +@item Must not contain @code{$C(0)}, @code{$C(201)}, or @code{$C(202)} +@end itemize + +@subsection String Quoting Rules +Strings in FreeM must be surrounded in double quotes: + +@example +SET MYSTRING="This is a string literal" +@end example + +If you want to include double quotes inside of a string, simply double them: + +@example +SET MYSTRING="This is a ""string literal"" with embedded double quotes" +@end example + @node Custom Types (Classes) @section Custom Types (Classes) @@ -4450,7 +4581,7 @@ Optionally, one or more comma-delimited A value of up to 255 characters in length @end itemize -The percent sign will force the named global into the @code{SYSTEM} namespace of the current FreeM environment. +A leading percent sign in the global name will force the named global into the @code{SYSTEM} namespace of the current FreeM environment. @node Creating Globals @section Creating Globals @@ -5602,9 +5733,6 @@ Raised when an attempt is made to use a @end table -@node Debugging -@chapter Debugging -@cindex debugging @node System Configuration @chapter System Configuration @@ -5613,56 +5741,101 @@ Raised when an attempt is made to use a @section Installing FreeM @cindex installation -@section Build Configuration -@cindex build configuration - -When configuring FreeM with the supplied @code{configure} script, there are some FreeM-specific options that may be used to compile in optional features, or exclude default ones: +@subsection Installation Methods +FreeM allows the following installation methods: @table @asis +@item Binary Repository +On recent versions the Ubuntu and Debian distributions of GNU/Linux, we provide package repositories from which FreeM may easily be installed. See the @emph{FreeM Wiki} for more information, and @emph{https://packages.coherent-logic.com} for instructions. -@item @code{--enable-mwapigtk} (EXPERIMENTAL) -Enables experimental support for the M Windowing API using the GTK3 libraries. Requires that you have GTK 3 libraries, their headers, and their dependencies installed on your system. +If available, this is the simplest method of installing FreeM. +@item Binary Packages +We provide binary packages of FreeM for @emph{dpkg} and @emph{rpm}-based distributions of GNU/Linux, and @emph{pkgadd} packages for Solaris 8-10. If you cannot use repositories, this is the easiest option. + +See @emph{https://freem.coherent-logic.com/binaries.cfm} for downloads and instructions. +@item Source Archive +If you prefer installing from source, we recommend that you download the latest @emph{.tar.gz} file from @emph{https://freem.coherent-logic.com/downloads.cfm}, and follow these steps: + +@example +$ gunzip freem-@emph{}.tar.gz +$ tar xf freem-@emph{}.tar +$ cd freem +$ ./configure # see the Build Configuration section for optional flags +$ make +$ sudo make install +@end example -Please consult your operating system's documentation for the correct commands to install the required libraries. +Once this process has been completed, you may proceed to @emph{Initial Configuration}. -@emph{Example} +Installation from source archive is the most challenging but flexible supported option for advanced users. +@item CVS Repository +If you wish to try the bleeding-edge development version of FreeM, you may do so by following these steps: -@example -$ ./configure --enable-mwapigtk +@verbatim +$ cvs -d :pserver:anonymous@cvs.coherent-logic.com:/home/cvsroot co freem +$ cd freem +$ ./autogen.sh +$ ./configure # see the Build Configuration section for optional flags $ make $ sudo make install -@end example +@end verbatim -@item @code{--enable-berkeleydb} (EXPERIMENTAL) -Enables experimental support for using the BerkeleyDB database as a global handler for FreeM global namespaces. Requires that you have the @code{libdb} library, headers, and dependencies installed on your system. +Once this process has been completed, you may proceed to @emph{Initial Configuration}. -Please consult your operating system's documentation for the correct commands to install the required libraries. +This installation method is by far the most complicated, and is intended only for those who wish to contribute to FreeM development. It is not intended for end users, and no technical support will be provided. -@emph{Example} +See the @emph{Contributor Guide} on the @emph{FreeM Wiki} for more information. +@end table +@subsection Build Configuration +@cindex build configuration -@example -$ ./configure --enable-berkeleydb -$ make -$ sudo make install -@end example +When configuring FreeM with the supplied @code{configure} script, there are some FreeM-specific options that may be used to compile in optional features, or exclude default ones: +@table @asis -@item @code{--without-readline} -Builds FreeM without GNU @code{readline} support, even if @code{readline} is installed on your system. +@item @code{--enable-mwapi} (EXPERIMENTAL) +Enables experimental support for the M Windowing API (ANSI @emph{X11.6-1995}) using the OSF/Motif widget toolkit. Requires that you have the @code{X11}, @code{Xt}, @code{ICE}, and @code{Xm} libraries, as well as all of their C header files. -Please note that building FreeM without GNU @code{readline} will also exclude REPL functionality and all direct-mode utility commands, i.e. @code{events}, @code{tdump}, @code{shmstat}, and @code{shmpages}. +Please consult your operating system's documentation for the correct commands to install the required libraries. @emph{Example} @example -$ ./configure --without-readline +$ ./configure --enable-mwapi $ make $ sudo make install @end example - @end table +@subsection Initial Configuration +Once FreeM is installed, you will need to configure it: + +@enumerate +@item Create a user and group, each named @emph{freem}, under which FreeM will run +@item Add any user accounts that will need to run FreeM to the @emph{freem} group +@item Have all users added in step 2 sign out and sign in for the new group membership to take effect +@item Run @code{fmadm configure} with superuser privileges to create the @code{DEFAULT} environment with @code{SYSTEM} and @code{USER} namespaces and default after-image journal settings, and populate the bundled vendor routines +@item Run @code{fmadm start environment} with superuser privileges to start the @code{DEFAULT} environment +@item Make sure the environment is ready by running @code{fmadm status environment} with superuser privileges +@end enumerate + +@subsubsection Creating Additional Environments +To create additional environments, do the following steps: + +@enumerate +@item Create a new user and group for the environment @emph{(optional)} +@item Run @code{fmadm configure -e=@emph{} -u=@emph{} -g=@emph{} [-E=@emph{true|false}]} @emph{(the @code{-E} flag enables or disables the environment)} +@item Run @code{fmadm start environment -e=@emph{}} to start the environment +@item Run @code{fmadm status environment} to make sure the environment is healthy +@end enumerate + +@subsubsection Additional Customization + +See the FreeM @emph{environment catalog} at @code{@emph{$PREFIX}/etc/freem/env.conf}, and the @emph{fmadm}(1) @code{man} page for more information. + +@emph{$PREFIX} represents the root location of your FreeM installation. This can be @code{/usr/local}, @code{/}, or others, depending on how FreeM was built and installed. + @node Accessing FreeM from C Programs @chapter Accessing FreeM from C Programs