copy one file to another : Sin ASin « Math « C / ANSI-C
copy one file to another
/*
Practical C Programming, Third Edition
By Steve Oualline
Third Edition August 1997
ISBN: 1-56592-306-5
Publisher: O'Reilly
*/
/* Usage *
* copy <from> <to> *
* *
* <from> -- the file to copy from *
* <to> -- the file to copy into *
****************************************/
#include <stdio.h>
#ifndef __MSDOS__ /* if we are not MS-DOS */
#define __UNIX__ /* then we are UNIX */
#endif /* __MSDOS__ */
#include <stdlib.h>
#ifdef __UNIX__
#include <sys/types.h> /* file defines for UNIX filesystem */
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#endif /* __UNIX__ */
#ifdef __MSDOS__
#include <fcntl.h> /* file defines for DOS filesystem */
#include <sys\stat.h>
#include <io.h>
#endif __MSDOS__
#ifndef O_BINARY
#define O_BINARY 0 /* Define the flag if not defined yet */
#endif /* O_BINARY */
#define BUFFER_SIZE (16 * 1024) /* use 16K buffers */
int main(int argc, char *argv[])
{
char buffer[BUFFER_SIZE]; /* buffer for data */
int in_file; /* input file descriptor */
int out_file; /* output file descriptor */
int read_size; /* number of bytes on last read */
if (argc != 3) {
fprintf(stderr, "Error:Wrong number of arguments\n");
fprintf(stderr, "Usage is: copy <from> <to>\n");
exit(8);
}
in_file = open(argv[1], O_RDONLY|O_BINARY);
if (in_file < 0) {
fprintf("Error:Unable to open %s\n", argv[1]);
exit(8);
}
out_file = open(argv[2], O_WRONLY|O_TRUNC|O_CREAT|O_BINARY, 0666);
if (out_file < 0) {
fprintf("Error:Unable to open %s\n", argv[2]);
exit(8);
}
while (1) {
read_size = read(in_file, buffer, sizeof(buffer));
if (read_size == 0)
break; /* end of file */
if (read_size < 0) {
fprintf(stderr, "Error:Read error\n");
exit(8);
}
write(out_file, buffer, (unsigned int) read_size);
}
close(in_file);
close(out_file);
return (0);
}
