Read file into array

Hey!

I've a text file (database.db) looking like this:

Code:

firstname1 lastname1 town1 country1 number1
firstname2 lastname2 town2 country2 number2
firstname3 lastname3 town3 country3 number3
firstname4 lastname4 town4 country4 number4
...

And I want to read each column in each row into a two dimensional array, so the result looks like this:

Code:

array {
 array {firstname1, lastname1, town1, country1, number1}, 
 array {firstname2, lastname2, town2, country2, number2}, 
 array {firstname3, lastname3, town3, country3, number3}, 
 array {firstname4, lastname4, town4, country4, number4},
 ...
}

How can I do this in C?

Thanks!

With regards,

Simon

What have you tried?

--
Mats

I've just made it this far:

Code:

char buffer[1024];	
db = fopen("database.db", "r");

while(fgets(buffer, 1024, db) != NULL)
{
   // Stuck here
}

I don't know how to go through each white space seperated string... :/ I tried to use fscanf inside the loop, but fscanf requires a pointer to a file descriptor (?) so I didnt get any further...

S

You could certainly use fscanf() - it uses the same pointer type as fgets(), so if db is OK for fgets() then it should work for fscanf() too.

Another option is to read the entire string and then use strtok() or sscanf() to split the string into separate data items.

--
Mats

sscanf seems to do the trick thanks! However, why doesnt this works? I get Segmentation fault.

PHP Code:

char *str = "this is a test";
char array[1][4];
sscanf(str, "%s %s %s %s", array[0][0], array[0][1], array[0][2], array[0][3]); 


It works if I read it into variables but arrays wont work...

S

not really array[1][4] is an array of char[4] with only 1 element
why not use something like this:

Code:

#define MAX_FIELD_LEN 40
struct tuple_s {
  char field1[MAX_FIELD_LEN];
  char field2[MAX_FIELD_LEN];
  char field3[MAX_FIELD_LEN];
  char field4[MAX_FIELD_LEN];
};
/* and then */
struct tuple_s * el = some_pointer_to_type_tuple_s;
sscanf(str, "%s %s %s %s", el->field1, el->field2, el->field3, el->field4);

Originally Posted by neobarn

sscanf seems to do the trick thanks! However, why doesnt this works? I get Segmentation fault.

PHP Code:

char *str = "this is a test";
char array[1][4];
sscanf(str, "%s %s %s %s", array[0][0], array[0][1], array[0][2], array[0][3]); 


It works if I read it into variables but arrays wont work...

S

Originally Posted by neobarn

sscanf seems to do the trick thanks! However, why doesnt this works? I get Segmentation fault.

PHP Code:

char *str = "this is a test";
char array[1][4];
sscanf(str, "%s %s %s %s", array[0][0], array[0][1], array[0][2], array[0][3]); 


It works if I read it into variables but arrays wont work...

S

You need to read a string into an array of characters -- you are trying to read a string into a char (array[0][0] is just a char -- array[0] is an array of chars). Probably you mean to define array as

Code:

char array[1][4][WORD_LEN];

where in your example WORD_LEN has to be at least 5.