Can a running C program access its own symbol table?

Question

I have a linux C program that handles request sent to a TCP socket (bound to a particular port). I want to be able to query the internal state of the C program via a request to

Answer 1

file: reflect.c

#include 
#include "reflect.h"

struct sym_table_t gbl_sym_table[1] __attribute__((weak)) = {{NULL, NULL}};

void * reflect_query_symbol(const char *name)
{
    struct sym_table_t *p = &gbl_sym_table[0];

    for(; p->name; p++) {
        if(strcmp(p->name, name) == 0) {
            return p->addr;
        }
    }
    return NULL;
}

file: reflect.h

#include 

struct sym_table_t {
    char *name;
    void *addr;
};

void * reflect_query_symbol(const char *name);

file: main.c

just #include "reflect.h" and call reflect_query_symbol

example:

#include 
#include "reflect.h"

void foo(void)
{
    printf("bar test\n");
}

int uninited_data;

int inited_data = 3;

int main(int argc, char *argv[])
{
    int i;
    void *addr;

    for(i=1; i

file:Makefile

objs = main.o reflect.o

main: $(objs)
        gcc -o $@ $^
        nm $@ | awk 'BEGIN{ print "#include "; print "#include \"reflect.h\""; print "struct sym_table_t gbl_sym_table[]={" } { if(NF==3){print "{\"" $$3 "\", (void*)0x" $$1 "},"}} END{print "{NULL,NULL} };"}' > .reflect.real.c
        gcc -c .reflect.real.c -o .reflect.real.o
        gcc -o $@ $^ .reflect.real.o
        nm $@ | awk 'BEGIN{ print "#include "; print "#include \"reflect.h\""; print "struct sym_table_t gbl_sym_table[]={" } { if(NF==3){print "{\"" $$3 "\", (void*)0x" $$1 "},"}} END{print "{NULL,NULL} };"}' > .reflect.real.c
        gcc -c .reflect.real.c -o .reflect.real.o
        gcc -o $@ $^ .reflect.real.o