xv6/cat.c
kaashoek 8b58e81077 i/o redirection in sh
better parsing of sh commands (copied from jos sh)
cat: read from 1 if no args
sbrk system call, but untested
getpid system call
moved locks in keyboard intr, but why do we get intr w. null characters from keyboard?
2006-08-23 01:09:24 +00:00

44 lines
567 B
C

#include "types.h"
#include "stat.h"
#include "user.h"
char buf[513];
void
rfile(int fd)
{
int cc;
while((cc = read(fd, buf, sizeof(buf) - 1)) > 0){
buf[cc] = '\0';
puts(buf);
}
if(cc < 0){
puts("cat: read error\n");
exit();
}
}
int
main(int argc, char *argv[])
{
int fd, i;
if (argc <= 1) {
rfile(0);
} else {
for(i = 1; i < argc; i++){
fd = open(argv[i], 0);
if(fd < 0){
puts("cat: cannot open ");
puts(argv[i]);
puts("\n");
exit();
}
rfile(fd);
close(fd);
}
}
exit();
}