Read Txt file Language C - c

Question

Hi guys I have this file struct:
0
2 4
0: 1(ab) 5(b)
1: 2(b) 6(a)
2: 0(a) 2(b)
3: 2(a) 6(b)
4: 5(ab)
5: 2(a) 6(b)
6: 4(b) 6(ab)
Each line will feed a struct with its data (numbers + letters).
What's the best way to read the line and get the strings I want?
Example:
0
2 4
0,1,ab,5,b
1,2,b,5,a
...
The lines may vary in size because we can have 1, 2, 3, .... numbers.
I already did it :
//struct
#define MAX_ 20
struct otherstats{ //struct otherStats
int conectstat[MAX_];//conection with others stats
int transitions[MAX_];//Symbols betwen conection ASCI
}tableStats[MAX_];
struct sAutomate{
int stat_initial; //initial
int stats_finals[MAX_]; //final orfinals
struct otherstats tableStats[MAX_]; //otherStats 0 1 2 3 4 5 6
};
/* eXample that what i want ..using the example
sAutomate.stat_initial=0
sAutomate.stats_finals[0]=2
sAutomate.stats_finals[1]=4
Others Stats table
//0
sAutomate.tableStats[0].conectstat[0]=1;
sAutomate.tableStats[0].conectstat[1]=5;
sAutomate.tableStats[0].transitions[0]=ab;
sAutomate.tableStats[0].transitions[1]=b;
//1
sAutomate.tableStats[1].conectstat[0]=2;
sAutomate.tableStats[1].conectstat[1]=6;
sAutomate.tableStats[1].transitions[0]=b;
sAutomate.tableStats[1].transitions[1]=a;
///etc
*/
void scanfile(){ //function to read the file
struct sAutomate st; //initialize st struct
char filename[] = "txe.txt";
FILE *file = fopen ( filename, "r" );
char buf[81];
char parts[5][11];
fscanf(file,"%d", &st.stat_initial);//read first line
printf("initial state : %d \n", st.stat_initial);
fscanf(file,"%d",&st.stats_finals);
fscanf(file,"%d",&st.stats_finals);
while (fgets(buf, sizeof(buf), stdin) != NULL)
{
if (sscanf(buf, "%10[^:]: (%10[^(], %10[^)]), (%10[^(], %10[^)])",
parts[0], parts[1], parts[2], parts[3], parts[4]) == 5)
{
printf("parts: %s, %s, %s, %s, %s\n",
parts[0], parts[1], parts[2], parts[3], parts[4]);
}
else
{
printf("Invalid input: %s", buf);
}
}
//fclose

Answer 1

First problem I see is you're overwriting stats_finals:
fscanf(file,"%d",&st.stats_finals);
fscanf(file,"%d",&st.stats_finals);
What you wanted to do here was:
fscanf(file,"%d",&st.stats_finals[0]);
fscanf(file,"%d",&st.stats_finals[1]);
To save off both the "2" and the "4" from the text file.
Second major problem is you're reading from stdin:
while (fgets(buf, sizeof(buf), stdin) != NULL)
That doesn't read your text file, that reads input from the keyboard... So you wanted that to be:
while (fgets(buf, sizeof(buf), file) != NULL)
Third (minor) problem is that fscanf() will not read newlines, and fgets() will. This means when you go from reading your second stats_finals to the first read in the while loop, your first input will just be the left over newline character. That's not a big deal since you check for "invalid input", but it's worth noting.
Finally, your sscanf looks wrong to me:
sscanf(buf, "%10[^:]: (%10[^(], %10[^)]), (%10[^(], %10[^)])",
^ ^
That's a width of 10, Why are you checking for commas? You didn't
I don't think that's have any in your text file
what you wanted...
I think this is more what you were looking for:
sscanf(buf, "%[0-9]: %[0-9](%[^)]) %[0-9](%[^)])",
^
takes a digit (0 to 9)
EDIT
Missed your original point. If you don't know how long the strings will be that you're reading, you can't use sscanf(). It's that simple. :)
The scanf family assumes you know how many objects you'll be parsing and the format string takes in that many. There are other options however.
Read a single line with fgets as you're doing, but then you can tokenize it. Either with the C function strtok or by your own hand with a for loop.
One note however:
Since you don't know how long it is, this: char parts[5][11]; is not your best bet. This limits you to 2 entries... probably it would be better to do this dynamically (read the line then allocate the correct size to store your tokens in.)

Answer 2

If you really don't know how many numbers and letters the line will contain, why are you reading a fixed amount of numbers and letters?
You could read the whole line with fgets and then parse it with a tokenizer like strtok, something like this:
const char* const DELIMITERS = " ";
int i; // index for tableStats
char* token;
token = strtok(line, DELIMITERS);
// first integer
if (token == NULL || sscanf(token, "%d:", &i) < 1)
// error
/* it seems like you should have at least one element in your "list",
* otherwise this is not necessary
*/
token = strtok(NULL, DELIMITERS);
if (token == NULL || sscanf(token, "%d(%[^)])",
&(tableStats[i].connectstat[0]),
&(tableStats[i].transitions[0])) < 2)
// error
// read optional part
for (int j = 1; (token = strtok(NULL, DELIMITERS)) != NULL; ++j)
if (sscanf(token, "%d(%[^)])", &(tableStats[i].connectstat[j]),
&(tableStats[i].transitions[j])) < 3)
break;
Remember that strtok changes the string, make a copy of it if you still need it.
Obviusly the code is for the arbitrary long lines, reading the first two lines is trivial.