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The C main program,

StrVarMain.c

#include <stdio.h> #include <string.h>

struct TVarLenStr {

int nbytes; char a[25];

};

extern void StrVar(char *, char *, struct TVarLenStr *);

int main(void)

{

struct TVarLenStr vls;

char s10[10], s80[80], s25[25];

vls.nbytes = 0; StrVar(s10, s80, &vls); strncpy(s25, vls.a, vls.nbytes);

printf(" s10 = '%s' \n s80 = '%s' \n s25 = '%s' \n", s10, s80, s25);

printf(" strlen(s25) = %d \n", strlen(s25));

}

The commands to compile and execute StrVar.p and StrVarMain.c

hostname% pc -c StrVar.p

hostname% cc StrVar.o StrVarMain.c -lpc hostname% a.out

s10='abcdefghi'

s80='abcdefghijklmnopqrtstuvwxyz'

s25='varstr'

strlen(s25)=6

Fixed Arrays

For a fixed array parameter, pass the same type and size by reference, as shown in the following example:

The C–Pascal Interface

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