guile/scripts/README

Overview and Usage
------------------

This directory contains Scheme programs, some useful in maintaining Guile.
On "make install", these programs are copied to PKGDATADIR/VERSION/scripts.

You can invoke a program from the shell, or alternatively, load its file
as a Guile Scheme module, and use its exported procedure(s) from Scheme code.
Typically for any PROGRAM:

  (use-modules (scripts PROGRAM))
  (PROGRAM ARG1 ARG2 ...)

For programs that write to stdout, you might try, instead:

  (use-modules (scripts PROGRAM))
  (with-output-to-string (lambda () (PROGRAM ARG1 ARG2 ...)))

Note that all args must be strings.

To see PROGRAM's commentary, which may or may not be helpful:

  (help (scripts PROGRAM))

To see all commentaries and module dependencies, try: "make overview".

If you want to try the programs before installing Guile, you will probably
need to set environment variable GUILE_LOAD_PATH to be the parent directory.
This can be done in Bourne-compatible shells like so:

  GUILE_LOAD_PATH=`(cd .. ; pwd)`
  export GUILE_LOAD_PATH

[FIXME: Can someone supply the csh-compatible equivalent?]



How to Contribute
-----------------

See template file PROGRAM for a quick start.

Programs must follow the "executable module" convention, documented here:

- The file name must not end in ".scm".

- The file must be executable (chmod +x).

- The module name must be "(scripts PROGRAM)".  A procedure named PROGRAM w/
  signature "(PROGRAM . args)" must be exported.  Basically, use some variant
  of the form:

  (define-module (scripts PROGRAM)
    :export (PROGRAM))

  Feel free to export other definitions useful in the module context.

- There must be the alias:

  (define main PROGRAM)

  However, `main' must NOT be exported.

- The beginning of the file must use the following invocation sequence:

  #!/bin/sh
  main='(module-ref (resolve-module '\''(scripts PROGRAM)) '\'main')'
  exec ${GUILE-guile} -l $0 -c "(apply $main (cdr (command-line)))" "$@"
  !#

Following these conventions allows the program file to be used as module
(scripts PROGRAM) in addition to as a standalone executable.  Please also
include a helpful Commentary section w/ some usage info.


[README ends here]