Properly using sscanf

Question

I am supposed to get an input line that can be in of any of the following formats:

• There must be space between word 1 and word 2.
• There must be a comm

Answer 1

This is beyond the scope of scanf and friends, to be perfectly honest; in addition to the answers of "write your own simple parser", you could to invest in yacc to parse the grammer (the lexer is left as an exercise for the reader):

line: oneword | twowords | threewords;
oneword: word;
twowords: word word;
threewords: word word word;
word: STRING;

This may be overkill for you here, but if you ever need to parse even more than marginally complex formats, it's a lifesaver.