Macro processor for C and other files.
Operate interactively, unbuffered, ignoring interrupts.
Specify flag-level debugging.
Print help message, then exit.
Specify the length of debugging output.
Place output in file. Despite the name, print error messages on standard error.
Prepend m4_ to all built-in macro names.
Insert #line directives for the C preprocessor.
Insert name into symbol table as undefined. Trace macro from the point it is defined.
Print version, then exit.
Set the size of the pushback and argument collection buffers to n (default is 4096).
Define name as value or, if value is not specified, define name as null.
Consider all warnings to be fatal, and exit after the first of them.
Record m4’s frozen state in file for later reloading.
Behave like traditional m4, ignoring GNU extensions.
Set symbol-table hash array to n (default is 509).
Search directory for include files.
Change artificial nesting limit to n.
Suppress warning messages.
Load state from file before starting execution.