server/file.c


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/*
 * server/file.c
 */


#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "file.h"


int file_open(char *filename)
{
	int fd = open(filename, O_RDONLY);
	if (fd == -1)
		return -1;

	struct stat st;
	if (fstat(fd, &st) == -1)
		return -1;

	return fd;
}


int file_getsize(int fd, off_t *size)
{
	*size = lseek64(fd, 0, SEEK_END);

	if (*size == -1)
		return -1;

	return 0;
}


int file_read(int fd, void *buf, size_t size, off_t pos)
{
	off_t newpos = lseek(fd, pos, SEEK_SET);

	if (newpos == -1)
		return -1;

        size_t nleft = size;
        ssize_t nread;
        char *ptr = buf;

        while (nleft > 0) {
                if ((nread = read(fd, ptr, nleft)) < 0) {
                        if (errno == EINTR)
				continue;

			return -1;
		}

		if (nread == 0) {
                        break;
                }

                nleft -= nread;
                ptr += nread;
        }

        return 0;
}