Thread: Start of file probs

Sorry to keep pestering people but I'm getting an error I can't seem to bypass.

Code:

char process (void) {       
   char read;   
   while (read=fgetc(fptr)!=EOF) {
   	if ((read >= 65) && (read <= 90)) {
      	read = convert (read);};//converts to lower class if needed
      insert_node (&tree,read);
		return read;
}

This isn't the full code but a function I've written. The idea is to basically read a text file ( containing something like "hello" ) a character at a time and return the value it got.
My problem is that I only get one value returned whatever the contents of the file. ASCII 1, the start of file ( equivalent to EOF but at the start ) character. Any ideas why its only returning one and not just reading them all.
Thanks

> while (read=fgetc(fptr)!=EOF) {

Generally it's considered a GoodThing(TM) to write it this way:

while( (read=fgetc(fptr)) != EOF ) {

Also, you may not want to use 'read' for a variable name. There are low level read / write functions called, oddly enough, 'read' and 'write'.

Quzah.

If your intention was:
while( (read=fgetc(fptr)) != EOF )

then
>> char read;
Would be wrong. fgetc returns an int type. You need to use this to compare with EOF. Otherwise if you happen to read in a char with value 0xff, it will equal EOF and break unexpectedly. Declare it as an int type and if it's not EOF, treat it as a char.

I can't believe I spent so long racking my brain because I messed up my brackets. I'm sure it wont be the last time though, its annoying how you can read something so many times and yet not see it.

I have a function that creates a node in a binary tree:

Code:

void insert_node ( struct node **root, char data ) {
    if ( *root == NULL ) {
        // a new leaf is needed
        struct node *newnode = (struct node*) malloc( sizeof( struct node ) );
        newnode->data = data;
        newnode->left = NULL;
        newnode->right= NULL;
        *root = newnode;
    } else {
        // decide which way to go
        if ( data < (*root)->data ) {
            insert_node( &(*root)->left, data );
        } else {
            insert_node( &(*root)->right, data );
        }
    }
}

( Thanks all who ironed out my errors with it )
If I call it myself multiple times it works fine:
insert_node (&tree,'c')
insert_node (&tree,'d')
insert_node (&tree,'e')

Inside my loop however it will only create one node, despite how many times its called:

Code:

while( (read=fgetc(fptr)) != EOF )  {
   	if ((read >= 65) && (read <= 90)) {
      	read = convert (read);};
      insert_node (&tree,read);

Do you think this be caused by the value of read not being updated properly or maybe it's my insersion function that doesn't like being called multiple times?
Thanks

I didn't know you could do that.

Originally posted by crag2804
I didn't know you could do that.

Welcome to the poor man's debugger:

printf("%c has been added to the list\n", data );

Quzah.