Question

The following will only read until the next white space occurs, excluding it

fscanf (list_in, "%s", keywords);

Answer 1

If I understand your question correctly, you could use a character class:

fscanf( list_in, "%[^ \r\n\t]", keywords );

Of course, to avoid buffer overruns, you should always set a maximum length when reading strings with (f)scanf, as in:

char keywords[81];

fscanf( list_in, "%80[^ \r\n\t]", keywords );

---

Edit: If you want to include the trailing whitespace character in the string, you could read it separately into a char variable using a %c directive, and either process it that way or append it to the string:

char keywords[82], space;
int n;

fscanf( list_in, "%80[^ \r\n\t]%c", keywords, &space );

n = strlen( keywords );
keywords[n] = space;
keywords[n+1] = '\0';

(Of course, to be extra careful, you should also check the return value of fscanf to make sure you didn’t, for example, hit the end of the input file.)