System I/O

[thescratchy]

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?

#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;
}

[brewbuck]

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

Should be

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

[thescratchy]

k ty, but it still doesnt work

[nadroj]

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.

[thescratchy]

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.

[nadroj]

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

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.

[thescratchy]

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