falcon

falcon(1)                     Falcon User Manuals                    falcon(1)



NAME
       falcon - The Falcon Programming Language command line interpreter


SYNOPSIS
       falcon [options] [main_script] [script_options]


DESCRIPTION
       The falcon command line interpreter is used to launch, compile,
       assemble or debug scripts written in the Falcon Programming Language.
       The command line interpreter pushes the core module and the rtl module
       in the script load table, so they are available by default to all the
       scripts.

       The default operation is that of launching the given script, or read it
       from the standard input if the script name is not given. By default,
       falcon saves also the compiled module of the script in the same
       directory where it is found, changing the extension to ".fam".

       The main_script can be a "logical" module name, a relative path or an
       absolute path. In case it's a logical module name, that is, a script
       name without extension nor leading path, it is searched through the
       load path. The default load path is determined by the compilation
       options of the interpreter, and usually it includes the current
       directory. The environment variable FALCON_LOAD_PATH and the command
       line option -L can change the default module search path.

       When the main module is found, its path is added to the module search
       path; in other words, there isn't any need to specify the path
       containing the main module to have other modules in its same directory
       to get loaded. The main module and other source Falcon module it loads
       can be stored in a directory that is not listed in the module search
       path; indicating an absolute or relative path as the main_script
       parameter will add that path on top of the active search path.

       If not differently specified, falcon will search for .fam modules newer
       than the relative .fal source scripts and will load those ones instead
       of compiling the sources.

       Options past the script name will be directly passed in the args[]
       global variable of the script.

       The interpreter is compatible with the UNIX script execution directive
       "#!".  A main script can have on the very first line of the code the
       directive

       #!/path/to/falcon

       to declare to the shell that the falcon command line is to be loaded.
       If falcon command line interpreter is also in the system PATH
       environment variable, which is usually the case of a normal
       installation, then the interpreter directive may also be simply

       #!/bin/env falcon

       It is then simply necessary to make the main script executable with

       chmod 744 script_name

       to be able to call the script directly.

       Scripts executed in this way will add their path to the falcon module
       load path as soon as they are loaded, so other modules referenced by
       them will be searched in the directory where they resides before being
       searched elsewhere.

       Options to the falcon compiler may be passed normally by writing them
       after the execution directive in the main script.

       Since version 0.8.12, the falcon command line interpreter has also an
       interactive mode which accepts statements and provide results as the
       expressions are evaluated.



OPTIONS
       -c     Compile but do not execute. This makes falcon to compile the
              given module into a .fam file and then terminate.  By default,
              the .fam file is written to a file with the same name as the
              input one, with the .fam extension.

       -C     Check for memory leaks in VM execution. Like the -M option of
              faltest, this function sets the falcon engine memory allocators
              to slower functions that checks for memory to be allocated and
              deallocated correctly during the execution of a module. If the
              script is executed, before Falcon exits it writes a small report
              to the standard output.

       -d <directive>=<value>
              Sets the given directive to the desired value. Compilation
              directives and their values are the ones that scripts can set
              through the directive statement.

       -D <constant>=<value>
              Sets the given constant to the desired value. Constants are made
              available at compile time, and can be employed in macro and meta
              compilation.

       -e <enc>
              Set given encoding as default for VM I/O. Unless the scripts
              select a different I/O encoding, the streams that are provided
              to the falcon VM (like the output stream for printf) are encoded
              using the given ISO encoding. This overrides the default
              encoding that is detected by reading the environment settings.
              In example, if your system uses iso-8859-1 encoding by default,
              but you want your script to read and write utf-8 files, use the
              option -e utf-8

              The -e option also determines the default encoding of the source
              files. To override this, use -E

       -E <enc>
              Set source script encoding. As -e , but this determines only the
              encoding used by falcon when loading the source scripts. This
              options overrides -e values, so it can be used to set the script
              encoding when they have to read and write from different
              encodings.

       -f     Force recompilation of modules even when .fam are found.

       -h or -?
              Prints a brief help on stdout and exits.

       -i     Interactive mode. Falcon interpreter reads language statements
              from a prompt and present evaluation results to the user.

       -l <lang_code>
              Select a different language code for internationalized programs.
              This option loads an alternate string table for all the modules
              loaded. If the table doesn't exist or if the modules doesn't
              have a .ftr file containing the translation, the operation
              silently files and the original strings are used instead.
              Language codes should be in the international ISO format of five
              characters with a language name, an underscore and the regional
              code, like in en_US

       -L <path>
              Changes the default load path. This overrides both the internal
              built in settings and the contents of environment variable
              FALCON_LOAD_PATH. Each directory in the path should be separated
              by ";" and use forward slashes, like this:

              falcon -L


       -m     Use temporary files for intermediate steps. By default
              compilation is completely performed in memory; this option makes
              falcon to use temporary files instead.

       -M     Do NOT save the compiled modules in '.fam' files.


       -o <fn>
              Redirects output to <fn>. This is useful to control the output
              of falcon when using options as -c, -a, -S etc.  If <fn> is a
              dash (-) the output is sent to stdout.

       -p <module>
              Preloads the given module as if it were loaded by the main
              script.

       -P     Ignore default load paths and uses only the paths set via the -L
              switch.

       -r     Ignore source files and only use available .fam. This does not
              affects the main script; use the -x option if also the main
              script is a pre-compiled .fam module and source script must be
              ignored.

       -S     Produce an assembly output. Writes an assembly representation of
              the given script to the standard output and the exit. Use -o to
              change file destination.

       -t     Generates a syntactic tree of the source and writes it to the
              standard output, then exits. The syntactic tree is a
              representation of the script that is known by the compiler and
              used by the generators to create the final code. This option is
              useful when debugging the compiler and to test for the correct
              working of optimization algorithm.

       -T     Force input parsing as .ftd (Falcon Template Document).
              Normally, only files ending with ".ftd" (case sensitive) are
              parsed as template document; when this switch is selected, the
              input is treated as a template document regardless of its name.

       -v     Prints copyright notice and version and exits.

       -w     After execution, requires the user to confirm program
              termination by pressing <enter>.  This helps in point & click
              environments, where Falcon window is closed as soon as the
              program terminates.

       -x     Executes a pre-compiled .fam module.

       -y     Creates a template file for internationalization.  This option
              creates a single .ftt file from a single source, .fam module or
              binary module. By default, the name of the template is the same
              as the module plus ".temp.ftt" added at the end; it is possible
              to change the destination template file using the -o option.


FILES
       /usr/lib/libfalcon_engine.so
              Default location of the Falcon Engine loadable module.

       /usr/lib/falcon
              Default directory containing Falcon binary modules.


ENVIRONMENT
       FALCON_LOAD_PATH
              Default search path for modules loaded by the scripts.


       FALCON_SRC_ENCODING
              Default encoding for the source scripts loaded by falcon (when
              different from the system default).


       FALCON_VM_ENCODING
              Default encoding for the VM I/O streams (when different from
              system default).


AUTHOR
       Giancarlo Niccolai <gc@falconpl.org>


SEE ALSO
       falrun(1) faldisass(1) fallc.fal(1)


LICENSE
       This document is released under the "GNU Free Documentation License,
       version 1.2".  On Debian systems, the complete text of the Free
       Documentation License, version 1.2, can be found in
       /usr/share/common-licenses/.




Falcon toolset                    April 2007                         falcon(1)