System I/O

Hello

I am trying to open 2 inputfiles and create 1 outputfile.
This outputfile will be a concatenation of the 2 inputfiles.

I want to copy the first file to the outputfile but when i try to read the outputfile I get an error : U dont have permission to open the document ......

Is there someone who knows the problem?

Code:

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>

#define BUFSIZE 512
char buff[BUFSIZE];

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

	int file1, file2, output;
	int bytes;

	if (argc != 4){
		perror("ERROR");
		exit(0);
	}

	if ((file1 = open(argv[1], O_RDONLY)) < 0){
		perror("ERROR");
		exit(0);
	}

	if ((file2 = open(argv[2], O_RDONLY)) < 0){
		perror("ERROR");
		exit(0);
	}

	if ((output = open(argv[3], O_CREAT | O_WRONLY| S_IWRITE)) < 0){
		perror("ERROR");
		exit(0);
	}

	while ((bytes = read(file1, buff, BUFSIZE)) > 0)
		write(output, buff, BUFSIZE);
	
	return 0;
}

Originally Posted by thescratchy

Code:

	if ((output = open(argv[3], O_CREAT | O_WRONLY| S_IWRITE)) < 0){

Should be

Code:

	if ((output = open(argv[3], O_CREAT | O_WRONLY, S_IWRITE)) < 0){

k ty, but it still doesnt work

Originally Posted by thescratchy

I get an error : U dont have permission to open the document ......

Why don't you post the actual error message? Is there anything else you're saying/not saying that isn't accurate? The code (after the fix by brewbuck) seems to work fine for me. Do you have permission to read/write the various files? Verify the 2 files can be read, and that you have permission to write to wherever you're specifying.

Yes i have permission to read the input files. They are just on my desktop
and i am writing the output file also to my desktop.

When i try and open the output file, i get an error :

U heeft geen toestemming om het document 'concat.txt"' te openen.
Vraag uw computer of netwerkbeheerder om assistentie.

Translation:

U dont have permission to open the file.
Ask help at your networkmanger.

I am using mac btw.

Oh, you mean read with an editor, not like read the file in the program.

Originally Posted by http://www.warpspeed.com.au/cgi-bin/inf2html.cmd?..\html\book\Toolkt40\XPG4REF.INF+205

S_IWRITE Writing permitted

S_IREAD Reading permitted

When you create the file its only given "write" permissions, you probably want to give it (at least) also "read" permissions.

Yes, that is indeed the problem. TYVM

I thaught that the S_IREAD, S_IWRITE were used to read and write in your c program.
Thanx for the clarification