Thread: functions won't work together

Hi,

I'm reading in a file called openInFile and then passing it line by line to two functions as follows....

while (fgets(line, sizeof(line), openedInFile) != NULL) {
test_4_globalVariable(line);
test_4_function(line);
}

These two functions both work fine if I comment the other out, but if I try to call both of them, the first one works fine and the other produces strange results.

Any ideas?


Bill

How did you declare line?

If it's
char *line;

Then your code is broken


Also, if you have

test_4_globalVariable( char *line);
test_4_function( char *line);

Make them
test_4_globalVariable( const char *line);
test_4_function( const char *line);

Because if either modify the line, the other is in for a surprise.

I take it that 'line' is pointing to an array or something like that?
it's important that 'line' is pointing to something before using it

"line" is decalred as...

char line[1000];

i'm trying to read a text file line by line. the two functions that i call don't modify the line, though i am ready the tokens by splitting it...


char *x = strtok(line, delim);

and reading it token by token...

x = strtok(NULL, delim);

these shouldn't actually modify the line though........should they?!

Bill

i sort of know what the problem is but still need a little bit of help...

char line[1000] is getting passed to the 1st function where it is being tokenised. When the 2nd function tries to use "line", it is getting the tokenised version. That is why the two functions work independently, but not together (I assume). Therefore, I need to pass the original version of "line" to both functions. How do I do this? Do I have to make "line" a constant (and if so, how)?

I appreciate any help!

Bill

Then read the manual page for strtok much more carefully!!!

For example:
BUGS

Never use this function. This function modifies its first argument. The identity of the delimiting character is lost. This function cannot be used on constant strings.

Of course the 2nd function is going to have problems if the first has trampled all over the buffer with strtok

The fix is to make a copy of the line, then strtok the copy