Struct in header file produces error in source file

Question

I have a struct defined inside capi_utils.h that looks like the following:

#ifndef _CAPI_UTILS_H_
# define _CAPI_UTILS_H_

...

struct ScalarVariable{
    char name[63];
    float value;
    uint8_T DataID;
    char type[50];
};

...
#endif

Inside of capi_utils.c I tried creating a variable to hold the struct like this

struct ScalarVariable sVariable;

Which only produces an error when I try setting a value inside the struct like this:

sVariable.name = paramName;

Error message is:

capi_utils.c:27: error: invalid use of undefined type `struct ScalarVariable'

What am I doing wrong?

EDIT 1:

I just had to include capi_utils.h. Didn't think I had to because I had understood source files and headers different for some reason.

EDIT 2:

To clarify, I even got errors when trying to set DataID, not only the array.

void GetValueFromAdress(const char_T*  paramName,
                     void*          paramAddress,
                     uint8_T        slDataID,
                     unsigned short isComplex,
                     uint_T*        actualDims,
                     uint_T         numDims,
                     real_T         slope,
                     real_T         bias) {

sVariable.DataID = slDataID;

}

Would produce error: invalid use of undefined type 'struct ScalarVariable'

Also, the name field is an array. So sVariable.name = paramName; is wrong. — Andrew Henle
– Andrew Henle, Commented Jun 25, 2018 at 14:18
@Stargateur, Oh you have to do that? I thought they somehow were connected because it's a header for the source or something, heh.. Seems like it's working now though! Thanks :) — Kvixen
– Kvixen, Commented Jun 25, 2018 at 14:19
You can't assign arrays with =, simple as that. It has nothing to do with structs. Use strcpy. — Lundin
– Lundin, Commented Jun 25, 2018 at 14:21

gsamaras · Accepted Answer · 2018-06-25 14:34:42Z

1

In cape_utlis.c, you need to include the header file, like this:

#include cape_utlis.h

Moreover, change this:

sVariable.name = paramName;

to this:

strcpy(sVariable.name, paramName)

in order to copy the NULL-terminated string in C, you use the function strcpy, and not the assignment operator.

answered Jun 25, 2018 at 14:34

gsamaras

73.7k50 gold badges210 silver badges330 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Struct in header file produces error in source file

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related