#include #include #define MAXREADS 3 void main(void) { int fd, i; char buf[4]; fd = open("/mnt/acpi/battery", OREAD); if(fd < 0) sysfatal("couldn't open it"); for(i = 0; i < MAXREADS; i++){ pread(fd, buf, sizeof buf, 0); buf[sizeof(buf)-1] = '\0'; print(buf); } close(fd); exits("done"); }