xv6-65oo2/user/cat.c
2019-09-11 10:04:40 -04:00

44 lines
604 B
C

#include "kernel/types.h"
#include "kernel/stat.h"
#include "user/user.h"
char buf[512];
void
cat(int fd)
{
int n;
while((n = read(fd, buf, sizeof(buf))) > 0) {
if (write(1, buf, n) != n) {
printf("cat: write error\n");
exit(1);
}
}
if(n < 0){
printf("cat: read error\n");
exit(1);
}
}
int
main(int argc, char *argv[])
{
int fd, i;
if(argc <= 1){
cat(0);
exit(1);
}
for(i = 1; i < argc; i++){
if((fd = open(argv[i], 0)) < 0){
printf("cat: cannot open %s\n", argv[i]);
exit(1);
}
cat(fd);
close(fd);
}
exit(0);
}