Import guile-1.8 as multiple upstream tarball component

[lilypond.git] / guile18 / examples / scripts / hello

diff --git a/guile18/examples/scripts/hello b/guile18/examples/scripts/hello
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+#! /usr/local/bin/guile -s
+!#
+;;; Commentary:
+
+;;; This is the famous Hello-World-program, written for Guile.  It is a
+;;; little bit enhanced in that it understands the command line options
+;;; `--help' (-h) and `--version' (-v), which print a short usage
+;;; decription or version information, respectively.
+
+;;; Author: Martin Grabmueller
+;;; Date: 2001-05-29
+
+;;; Code:
+
+(use-modules (ice-9 getopt-long))
+
+;; This is the grammar for the command line synopsis we expect.
+;;
+(define command-synopsis
+  '((version (single-char #\v) (value #f))
+    (help    (single-char #\h) (value #f))))
+
+;; Display version information.
+;;
+(define (display-version)
+  (display "hello 0.0.1\n"))
+
+;; Display the usage help message.
+;;
+(define (display-help)
+  (display "Usage: hello [options...]\n")
+  (display "  --help, -h           Show this usage information\n")
+  (display "  --version, -v        Show version information\n"))
+
+;; Interpret options, if --help or --version was given, print out the
+;; requested information and exit.  Otherwise, print the famous
+;; message.
+;;
+(define (main options)
+  (let ((help-wanted (option-ref options 'help #f))
+       (version-wanted (option-ref options 'version #f)))
+    (if (or version-wanted help-wanted)
+       (begin
+         (if version-wanted
+             (display-version))
+         (if help-wanted
+             (display-help)))
+       (begin
+         (display "Hello, World!") (newline)))))
+
+;; Call the main program with parsed command line options.
+;;
+(main (getopt-long (command-line) command-synopsis))
+
+;; Local variables:
+;; mode: scheme
+;; End: