Bash Pre-Processor

There are certain instances where you need to statically include other scripts within a primary single script. For example, RPM spec %pre scripts can't utilise any scripts that are deployed during the installation of an RPM, because those scripts just simply aren't available. In those situations, you need a mechanism through which you can perform CPP style static inclusions of other files. The Bash Pre-Processor hopes to solve this problem, by providing the functionality of the C Pre-Processor, targeted at Bash scripts.

This tool is written in Bash, so itt may not perform as well as other scripts written in Python or Perl, but Bash Pre-Processor aims to be as portable as possible, requiring only Bash and core utilities.

Controlling Bash Pre-Processor

You can control the behaviour of the Bash Pre-Processor through the use of environment variables or through command line switches.

Supported Directives

#include

Include a file defined in the standard include path, defined by the BASHINC environment variable or paths specified with the -I dir flag.

#include "path/filename"

Include a file relative to the directory of the file being processed. If the path starts with a forward slash, then the path is searched relative to the root file system.

#define NAME VALUE

Create a new definition. If NAME is already defined, bashpp will terminate with an error message.

#undef NAME

Undefine the NAME definition if defined. If NAME is not defined, NAME will remain undefined.

#ifdef NAME

If NAME is defined, everything that follows to the #endif or #else statement is written to the output file. If NAME is undefined, everything that follows is omitted.

#ifndef NAME

Negated implementation of #ifdef

#else

Inverse of the preceding #ifdef or #ifndef expression.

Command Line Options

For command line options, see the usage by running:

$ bashpp --help

Here are the options as of 7 Aug 2015.

Usage: bashpp [options] file...
Options:
  -I dir                Add the directory defined by dir to the include path.

  -D name               Predefine name as a macro, with definition 1.

  -D name=definition    The contents of definition are tokenized and processed
                        as if they appeared during translation in a #define
                        directive.

                        If you are invoking the preprocessor from a shell or
                        shell-like program you may need to use the shell's
                        quoting syntax to protect characters such as spaces that
                        have a meaning in the shell syntax.

                        -D and -U options are processed in the order they are
                        given on the command line.

  -o file               Place the output into <file>

  -v                    Verbose mode.

Arguments:
    file                Specify an input file.  By default, input is read from
                        standard input.

Copyright (C) 2015 Craig Phillips.  All rights reserved.