The simplest way to use GASP is to run it as a filter and assemble its output; for example, use the following input.
% gasp prog.asm | as -o prog.o
Naturally, there are also a few GASP command-line options to allow you to request variations on this basic theme. Here is the full set of possibilities for the GASP command line.
gasp [
-a | --alternate ]
[-c char
| --commentchar char ]
[ -d | --debug
] [ -h | --help ] [ -M | --mri ]
[-o outfile
| --output outfile ]
[ -p | --print
] [ -s | --copysource ]
[ -u | --unreasonable
] [ -v | --version ]
infile...
infile...
The input file
names. You must specify at least one input file; if you specify more, gasp
preprocesses them all, concatenating the output in the order you list the
infile
arguments. Mark the end of each input file with the preprocessor command
.END.
See Miscellaneous
commands.
-a
--alternate
Use alternative
macro syntax. See Alternate
macro syntax for a discussion of how this syntax differs from
the default GASP syntax.
-c 'char'
--commentchar 'char'
Use char
as the comment character. The default comment character is !.
For example, to use a semicolon as the comment character, specify -c';'
on the GASP command line. Since assembler command characters often have
special significance to command shells, it is a good idea to quote or escape
char
when you specify a comment character.
For the sake of simplicity, in Using GASP, all examples use the
default comment character, !.
-d
--debug
Show debugging
statistics. In this version of GASP, this option produces statistics about
the string buffers that GASP allocates internally. For each defined buffersize
s,
GASP shows the number of strings n
that it allocated, using the following input.
strings size s : n
GASP displays these statistics on the standard error stream, when done preprocessing.
-h
--help
Display a summary
of the GASP command line options.
-M
--mri
Use MRI compatibility
mode. Using this option causes GASP to accept the syntax and pseudo-ops
used by the Microtec Research ASM68K
assembler.
-o outfile
--output outfile
Write the
output in a file called outfile.
If you do not use the -o
option, GASP writes its output on the standard output stream.
-p
--print
Print line numbers.
GASP obeys this option only if you also specify -s
to copy source lines to its output. With -s
-p, GASP displays
the line number of each source line copied (immediately after the comment
character at the beginning of the line).
-s
--copysource
Copy the source
lines to the output file. Use this option to see the effect of each preprocessor
line on the GASP output. GASP places a comment character (!,
by default) at the beginning of each source line it copies, so that you
can use this option and still assemble the result.
-u
--unreasonable
Bypass “unreasonable
expansion” limit. Since you can define GASP macros inside other macro definitions,
the preprocessor normally includes a sanity check. If your program requires
more than 1,000 nested expansions, GASP normally exits with an error message.
Use this option to turn off this check, allowing unlimited nested expansions.
-v
--version
Display the GASP
version number.