Reading in integers only from a file.

[UNH1995]

I have a file that I need to read in line coordinates from inorder to find the vectors and cross products. I always struggle with inputting from a file so I need some help.

The file is in this format:

L1= (35,70) (35,4) L2 =(63,4) (75,91)
L1= (65,91) (16,26) L2 =(92,61) (93,89)
L1= (77,3) (50,35) L2 =(39,5) (27,32)
L1= (10,30) (68,47) L2 =(51,23) (30,82)
L1= (9,95) (64,64) L2 =(17,52) (27,91)
L1= (3,11) (64,84) L2 =(2,24) (54,43)
L1= (56,45) (41,2) L2 =(68,65) (84,48)
L1= (20,75) (54,99) L2 =(2,20) (90,84)

The numbers represent the endpoints of each lines (2 lines). I need to extract only the numbers, prefferably in order and perform some calculations on them. Can anyone tell me how to evaluate a line at a time or pull out only the numbers?

 

[bearsite4]

If you know the format of your file is always going to be like the one you gave above you can just read in 5 char's at the beginning 'L1= (' and then read a integer '35' then a char ',' and so on.

 

[fireblade]

L1= (35,70) (35,4) L2 =(63,4) (75,91)

I would read in an entire line as a string and then
search the string for a ( character, copy the next set of
characters to a buffer (i.e. a character string) until a ) is encountered. Continue searching for another ( and again place the characters into a second buffer until ) is encountered. Repeat procedure for third and fourth buffers.

The buffers will then contain

Buffer1 35,70
Buffer2 35,4
Buffer3 63,4
Buffer4 75,91

You can simply do a sscanf on the four buffers to get the
required numbers (i.e. sscanf (Buffer1, "%d,%d", &L1, &L2))

 

[Guest_imported]

you get a line from the file to char array chmessage, and then try this,

int x[10];
sscanf(chmessage,"L%d= (%d,%d) (%d,%d) L%d =(%d,%d) (%d,%d)",
&x[0], //
&x[1],&x[2],&x[3],&x[4], // (35,70)(35,4)
&x[5], //
&x[5],&x[6],&x[7],&x[8]); // (63,4)(75,91)