How to read from a file except the last line in C?

Question

I am having a file where i need to read the data and store it into a structure.

10001 john
10002 david
10003 randy
10/10/2010 15:50:55 Updated by : Name

now for the above file i need to read the data from '10001' & 'john' till '10003' & 'randy' except the last line(End of the file).

How to do it in C?

Update : last line will be dynamic.

Answer 1

read line by line. When you get EOF discard last line.

Edit:

while (fgets(line, length, file) && !feof(file))
{
   /* process the line */ 
}

Answer 2

What would you do if the file didn't have that last line? Presumably in some kind of loop, read each line and save it.

You could just add an "if" before you save, checking whether the line matched your "End of the file".

Generally, with these kind of problems, break the problem down into bits you can understand. Then fits the bits together.

You might also want to consider what you should do if the file looks like

10001 john
10002 david
Silly line in middle of file
10003 randy
End of the file
10003 mr unexepected

Your application should be resilient to weird input.

Answer 3

char line[81];
FILE *f=fopen("file","rt");

while( fgets(line,sizeof line,f) )
{
int tag1;
char tag2[81];
if( 2==sscanf(line,"%d%80s",&tag1,tag2) )
{
/* do anything */
}
}