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zachmargolis/demo.sh

Last active August 29, 2015 14:03
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  1. zachmargolis revised this gist Jul 10, 2014. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion demo.sh
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    Original file line number Diff line number Diff line change
    @@ -1,4 +1,4 @@
    $ ./java-the-script
    $ ./java-the-script
    Usage: ./java-the-script -e JAVA_CODE
    -i, --import PACKAGE import PACKAGE before compiling code
    --debug debug mode: print the generated Java source
  2. zachmargolis revised this gist Jul 10, 2014. 1 changed file with 4 additions and 0 deletions.
    4 changes: 4 additions & 0 deletions java-the-script
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    Original file line number Diff line number Diff line change
    @@ -43,6 +43,10 @@ import_declarations = imports.map do |import|
    "import #{import};"
    end.join("\n")

    if !java_code.end_with?(';')
    java_code << ';'
    end

    java_source = <<JAVA
    #{import_declarations}
  3. zachmargolis revised this gist Jul 10, 2014. 1 changed file with 0 additions and 0 deletions.
    Empty file modified java-the-script
    100644 → 100755
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    Empty file.
  4. zachmargolis revised this gist Jul 10, 2014. 1 changed file with 8 additions and 0 deletions.
    8 changes: 8 additions & 0 deletions demo.sh
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    Original file line number Diff line number Diff line change
    @@ -1,2 +1,10 @@
    $ ./java-the-script
    Usage: ./java-the-script -e JAVA_CODE
    -i, --import PACKAGE import PACKAGE before compiling code
    --debug debug mode: print the generated Java source
    -e JAVA_CODE Java source to compile and run
    -h, --help Show this message
    $ echo "wooooo" | ./java-the-script -e 'System.out.println(STDIN.read().toUpperCase());'
    WOOOOO
    $ ./java-the-script -i java.util.Calendar -e 'System.out.println(Calendar.getInstance().get(Calendar.YEAR));'
    2014
  5. zachmargolis created this gist Jul 10, 2014.
    2 changes: 2 additions & 0 deletions demo.sh
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    @@ -0,0 +1,2 @@
    $ echo "wooooo" | ./java-the-script -e 'System.out.println(STDIN.read().toUpperCase());'
    WOOOOO
    97 changes: 97 additions & 0 deletions java-the-script
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    @@ -0,0 +1,97 @@
    #!/usr/bin/env ruby
    require 'optparse'
    require 'tmpdir'

    java_code = ""
    imports = []
    print_usage = false
    debug_mode = false

    parser = OptionParser.new do |opts|
    opts.banner = "Usage: #{$0} -e JAVA_CODE"

    opts.on('-i', '--import PACKAGE', 'import PACKAGE before compiling code') do |lib|
    imports << lib
    end

    opts.on('--debug', 'debug mode: print the generated Java source') do
    debug_mode = true
    end

    opts.on('-e JAVA_CODE', 'Java source to compile and run') do |java_expr|
    java_code = java_expr
    end

    opts.on_tail('-h', '--help', 'Show this message') do
    print_usage = true
    end
    end

    parser.parse!(ARGV)

    if java_code.empty? || print_usage
    puts parser
    exit 1
    end

    imports << 'java.io.BufferedReader'
    imports << 'java.io.InputStream'
    imports << 'java.io.InputStreamReader'
    imports << 'java.io.IOException'

    import_declarations = imports.map do |import|
    "import #{import};"
    end.join("\n")

    java_source = <<JAVA
    #{import_declarations}
    public class JavaTheScript {
    public static class StandardIn {
    private final BufferedReader reader;
    public StandardIn(InputStream in) {
    reader = new BufferedReader(new InputStreamReader(System.in));;
    }
    public String read() {
    StringBuilder builder = new StringBuilder();
    try {
    while (reader.ready()) {
    builder.append(reader.readLine());
    }
    } catch (IOException ex) {
    // chillin.
    }
    return builder.toString();
    }
    public String readLine() {
    try {
    return reader.readLine();
    } catch (IOException ex) {
    return "";
    }
    }
    }
    public static void main(String[] args) {
    StandardIn STDIN = new StandardIn(System.in);
    #{java_code}
    }
    }
    JAVA

    if debug_mode
    puts java_source
    exit 0
    end

    Dir.mktmpdir do |dir|
    Dir.chdir(dir) do
    java_filename = 'JavaTheScript.java'
    File.open(java_filename, 'w') { |f| f.write java_source }
    system("javac", java_filename)
    exec("java", "JavaTheScript")
    end
    end