Making fscanf Ignore Optional Parameter

Question

I am using fscanf to read a file which has lines like
Number <-whitespace-> string <-whitespace-> optional_3rd_column

I wish to extract the number and string out of each column, but ignore the 3rd_column if it exists

Example Data:
12 foo something
03 bar
24 something #randomcomment

I would want to extract 12,foo; 03,bar; 24, something while ignoring "something" and "#randomcomment"

I currently have something like

while(scanf("%d %s %*s",&num,&word)>=2)
{ 
assign stuff 
}

However this does not work with lines with no 3rd column. How can I make it ignore everything after the 2nd string?

Answer 1

Use fgets() to read a line at a time and then use sscanf() to look for the two columns you are interested in, more robust and you don't have to do anything special to ignore trailing data.

Answer 2

I often use gets() followed by an sscanf() on the string you just, er, gots.

Bonus: you can separate the test for end-of-input from the parsing.

Answer 3

It would appear to me that the simplest solution is to scanf("%d %s", &num, &word) and then fgets() to eat the rest of the line.

Answer 4

Bit of a question dodge, but this trick with the format identifier star %*s really helped me out as I've got a constant 3rd column. But, does anyone know where I can find out about it? I've no idea where it's from or what it does, but I guess it's just another part of the format specifiers that in some way allows scanf to scan then forget the value...?