How to open .ttcn file using C file open functions? - c

Question

I am working on TTCN-3 (Testing and Test Control Notation) scripting language. I wanted to prepare on guideline checker for this code files.
For that I want to read lines of TTCN-3 script file( some thing like file.ttcn ) one by one into a buffer. But for me fopen / sopen / open / fgetc / fscanf are not able to work properly and are not reading the file correctly. It is giving NULL. Is there any way I can read characters of it into a buffer. I think C cannot read files with more than three extension characters (like .ttcn). Forgive me if my assumption is wrong.
My Environment is Turbo C on windows.
Edit:
Yes I checked those errors also but they are giving unknown error for read()
and no such file or directory exists.
My code is as follows
#include <errno.h>
#include <io.h>
#include <fcntl.h>
#include <sys\stat.h>
#include <process.h>
#include <share.h>
#include <stdio.h>
int main(void)
{
int handle;
int status;
int i=0;
char ch;
FILE *fp;
char *buffer;
char *buf;
clrscr();
handle = sopen("c:\\tc\\bin\\hi.ttcn", O_BINARY, SH_DENYNONE, S_IREAD);
/here even I used O_TEXT and others/
if (!handle)
{
printf("sopen failed\n");
// exit(1);
}
printf("\nObtained string %s #",buf);
close(handle);
fp=fopen("c:\\tc\\bin\\hi.ttcn","r"); \\sorry for the old version of one slash
if(fp==NULL) \\I was doing it with argv[1] for opening
{ \\user given file name
printf("\nCannot open file");
}
ch=fgetc(fp);
i=0;
while(i<10)
{
printf("\ncharacter is %c %d",ch,ch);
i++; //Here I wanted to take characters into
ch=fgetc(fp); //buffer
}
getch();
return 0;
}

Answer 1

The most likely culprit is your Turbo C, an ancient compiler. It's techincally a DOS compiler, not Windows. That would limit it's RunTme Library to 8.3 filenames. Upgrade to something newer - Turbo C++ seems like a logical successor, but Microsoft's VC++ Express would work as well.

Answer 2

Your assumption is wrong about extensions. If fopen is returning NULL, you should output the result of strerror(errno) or use the perror() function to see why it failed.
Edit: The problem is probably because you have "c:\tc\bin\hi.ttcn". in C, "\t" is interpreted as tab, for example.
You could do
"c:\\tc\\bin\\hi.ttcn"
But this is extremely ugly, and your system should accept:
"c:/tc/bin/hi.ttcn"

Answer 3

MS-DOS does not know about long file names, thos including files with extensions longer than 3 characters. Therefore, the CRT provided by Turbo C most probably does not look for the name you are providing, but a truncated one - or something else.
Windows conveniently provides a short (i.e. matching the 8.3 format, most of the time ending in ~1 unless you play with files having the same 8-character prefix) file name for those; one way to discover it is to open a console window and to run "dir /x" in the folder your file is stored.
Find the short name associated to your file and patch it into your C source file.
Edit: Darn, I'll read the comments next time. All credits to j_random_hacker.

Answer 4

Now that you've posted the code, another problem comes to light.
The following line:
fp=fopen("c:\tc\bin\hi.ttcn","r");
Should instead read:
fp=fopen("c:\\tc\\bin\\hi.ttcn","r");
In C strings, the backslash (\) is an escape character that is used to encode special characters (e.g. \n represents a newline character, \t a tab character). To actually use a literal backslash, you need to double it. As it stands, the compiler is actually trying to open a file named "C:<tab>c<backspace>in\hi.ttcn" -- needless to say, no such file exists!