#pragma not working right in C?

Question

my first time really working with #pragma and for some reason I don't get the same output as the ones posted online, the functions don't print out, I use GCC v5.3 and clang v. 3.7. Here's the code

#include<stdio.h>

void School();
void College() ;

#pragma startup School 105
#pragma startup College
#pragma exit College
#pragma exit School 105

void main(){
    printf("I am in main\n");
}

void School(){
    printf("I am in School\n");
}

void College(){
    printf("I am in College\n");
}

and I compile with "gcc file.c" and "clang file.c". The output I get is "I am in main"

Answer 1

#pragma is not consistent across compilers. It is only meant to be used in odd situations with specific compilers/platforms. For a general program like this it should never be used.

A better way to accomplish this is with #define and #if. For example:

#include<stdio.h>

#define SCHOOL 1
#define COLLEGE 2

#define EDUCATION_LEVEL COLLEGE

void None();
void School();
void College();

void main(){
    #if EDUCATION_LEVEL == SCHOOL
        School();
    #elif EDUCATION_LEVEL == COLLEGE
        College();
    #else
        None();
    #endif
}

void None(){
    printf("I am in neither school nor college\n");
}

void School(){
    printf("I am in School\n");
}

void College(){
    printf("I am in College\n");
}