1 #include "types.h"
2 #include "stat.h"
3 #include "user.h"
4
5 char buf[512];
6
7 void
cat(int fd)8 cat(int fd)
9 {
10 int n;
11
12 while((n = read(fd, buf, sizeof(buf))) > 0) {
13 if (write(1, buf, n) != n) {
14 printf(1, "cat: write error\n");
15 exit();
16 }
17 }
18 if(n < 0){
19 printf(1, "cat: read error\n");
20 exit();
21 }
22 }
23
24 int
main(int argc,char * argv[])25 main(int argc, char *argv[])
26 {
27 int fd, i;
28
29 if(argc <= 1){
30 cat(0);
31 exit();
32 }
33
34 for(i = 1; i < argc; i++){
35 if((fd = open(argv[i], 0)) < 0){
36 printf(1, "cat: cannot open %s\n", argv[i]);
37 exit();
38 }
39 cat(fd);
40 close(fd);
41 }
42 exit();
43 }
44