Struct pointer problem

[fkheng]

I am facing a problem involving a pointer to a struct here, and i'm not sure if i'm getting the concept right...

i've attached the zip file, once unzipped, open the startup.c file and after compiling it, enter 'Francis' for username and 'Kheng' for password...

for menu, choose number 4, and for the next submenu, choose 1.

then for intake, type 'hf0271c'

and then press to see some text on the screen followed by an error message which will pop up...

this error can be traced to file reporting.h

under the displayReporting() function i hvae commented the problem, which involves a pointer to a struct...did i declare it properly, and am i allowed to use it in such a way? as i've used it elsewhere and it worked, w hereas now it makes the program hang...with an error message...

[fkheng]

to summarise my problem, i declared a pointer to a struct like this...

ACADEMICPROF *details;

then, in a function, i immediately assigned a value to the data member of the struct type it points to...

details->studentID[j] = *resultFields[i]; //this is a character assignment

is this wrong since i have not assigned any address to this pointer yet?

but this method did not give me problems when i used it earlier in my SESFunctions.h file...just that i substituted the struct name for USERPROF and the pointer name as *prof

[saravanan_ts]

In your reporting.h make this change.

struct ACADEMICPROF{
	char studentID[27];
	int semesterNumber;
	char subject[10];
	float incourse;
	float exam;
	float overall;
	struct ACADEMICPROF *next;
};

Is it working now?

[fkheng]

nope, if i take away that one, i get many errors, some of which state the i have a missing identifier ACADEMICPROF...

[saravanan_ts]

Oh!! Dear. just declare one structure of that type.

[fkheng]

sorry, but wat do u mean by that?

[Hammer]

With this:
>>details->studentID[j]= *resultFields[i];
are you trying to copy the string? If so, you need strcpy().

[fkheng]

yeap, i am trying to assign or copy, so i have to use strcpy()?

i'll try, thank you!

[fkheng]

okay, yeah i know, coz i rush into things without planning...

anyway, i tried with strcpy but it still didn't work...i really do not know wat the problem is...

[Hammer]

>>anyway, i tried with strcpy but it still didn't work...i really do not know wat the problem is
Then you didn't use it properly. Try writing a small program using those structs, just to get used to using strcpy on them. Post it here when you have trouble.

[anonytmouse]

to summarise my problem, i declared a pointer to a struct like this...

ACADEMICPROF *details;

then, in a function, i immediately assigned a value to the data member of the struct type it points to...

details->studentID[j] = *resultFields[i]; //this is a character assignment

is this wrong since i have not assigned any address to this pointer yet?

Yes. To avoid this problem you may want to prepend pointer names with p eg. pAcProfDetails. This tells you it is a pointer to an ACADEMICPROF struct. You must initialise a pointer before dereferencing it.

but this method did not give me problems when i used it earlier in my SESFunctions.h file...just that i substituted the struct name for USERPROF and the pointer name as *prof

Ok, so what is this?

prof = (USERPROF *) malloc (sizeof (USERPROF));

Looks like initialisation of prof to my simple mind.