libmawk_initialize_stage.3libmawk - Man Page

create a new libmawk context in 3 stages


#include <libmawk.h>

mawk_state_t *libmawk_initialize_stage1(void);

mawk_state_t *libmawk_initialize_stage2(mawk_state_t * m,int s ,char*"argv[]);

mawk_state_t *libmawk_initialize_stage3(mawk_state_t * m);


The libmawk_initialize_stage*() functions together do the same as libmawk_initialize() but allows the application to take actions between different stages. libmawk_initialize_stage1() returns a pointer to a newly created libmawk context. Any amount of libmawk contexts can live in parallel in an application.

libmawk_initialize_stage2() can be called after a succesful stage1 call.
Stage2 is responsible for processing the command line arguments and loading any script.

Arguments are the same as for a command line mawk session. Scripts are loaded (either from command line or from files using -f), variables are set (with -v), special options are set (with -W), etc. Unlike with libmawk_initialize(), the application may decide not to provide any script at this stage. All command line arguments are processed.

The most common case is that the application calls stage1 with no script, then already having a context makes some manipulations on it (for example registers some C functions that would be already called in the BEGIN part of the script that will be later loaded). Optionally before calling stage2 the application loads the actual script(s) using mawk_append_input_file().

libmawk_initialize_stage3() is called as a final step of the three-stage initialization process. Stage3 is responsible for running all the BEGIN parts of all scripts loaded at stage1 or stage2. It is useful to have stage3 in a separate call to allow applications to manipulate the context right before initializing the scripts.

Stage2 gets the pointer returned by stage1 and stage3 gets the pointer returned by stage2. Subsequent calls to libmawk functions should get the pointer returned by stage3.

Return Value

At stage 1 a pointer to a new libmawk context or NULL on error. Subsequent stages will return the same pointer or NULL on error.

See Also

libmawk_initialize_stage(3libmawk), libmawk_uninitialize(3libmawk), mawk_append_input_file(3libmawk).


2009-08-10 libmawk manual