LNK2001 error for program defined external variables

[GaryMeer]

I am getting a LNK2001 error when I try to use external variables as global variables in my program,. I have used these for decades in C on Unix. Now Visual Studio is getting LNK2001 errors from the linker when trying to link a C++ program I am developing. On every other system I have used the 1st module to refer to the external allocates space for it. Is Microsoft different? The code runs along the lines of:

----------------------------------------------------------------

header.h

#include <cstdio>

extern char programName[ FILENAME_MAX ];

void subr();

void subr2();

----------------------------------------------------------------

main.cpp

#include "header.h"

int main(argc, char **argv)

{

programName = argv[0];

subr();

subr2();

}

----------------------------------------------------------------

subr.cpp

#include "header.h"

void subr()

{

}

----------------------------------------------------------------

subr2.cpp

#include "header.h"

void subr2()

{

}


All of the routines compile cleanly, but then the linker error. Any ideas?

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