Thread: low level program in C

> void main(char *argv[])
Wrong in 2 places

int main(int argc, char *argv[])

I've no idea what you're opening, but is sure isn't the filename you typed in.

> inhandle = open(argv[1],O_RDONLY|O_BINARY);
Check for success/failure

> bytes=read(inhandle,buffer,512);
Unlike higher level functions like fgets(), this does not add a \0 to the end of the buffer (see your use of strlen() later on)
Ditto on the error checking

> j=strlen(buffer);
j = bytes;
would be better
Which kinda makes j redundant

The basic problem is that you need to count newlines in the buffer you read in.

How else are you supposed to know that you've printed just 24 lines.

This kinda means you can't just blast out a whole block of characters and hope it all fits nicely on screen.

Standard fopen/fgets seems to be better, at least you know where all the newlines are then

Code:

while ( fgets( buff, sizeof buff, fp ) != NULL ) {
    fputs( buff, stdout );
    if ( ++count == 25 ) {
        count = 0;
        /* pause */
    }
}

Originally posted by orthanc
Hi,

Thanks a lot for the rep. i was able to get the output.

But i still have two problems

1. how can i use write to print the result. ( for now i am using the for loop)

2. how to incorporate the end of page thing.

1) As Salem mentioned, switch to fopen() and fgets() instead of open/read

Then for your output use fprintf() specifying stdout for the screen. Depending on your compiler, stdprn may be defined for the printer. If not, fopen() the printer for output.

2) The trouble with adding the end-of-page thing is figuring out how big a page is. 24 lines used to be normal but I for one have used only 43, 50, or larger for years. depending on your OS and compiler, there may be functions you can call to get the window/screen size.