Unix system calls 5 Unix System Calls (open, read, write, close) // Unix system calls // open, read, write, close system calls #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> int main (int argc, char *argv[]) { int fd; int n_char=0; char buffer[10]; fd=open(argv[1],O_RDONLY); if (fd==-1) { printf(“File open error.”); exit(1); } while( (n_char=read(fd, buffer, 1))!=0) n_char=write(1,buffer,n_char); close(fd) return 0; }